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Essais D'Hydraulique Souterraine et Fluviale
... Using the discharge data of Cokragan Karstic Spring (with at least one discharge measurement per month between February 14, 2002, andFebruary 16, 2007) obtained from the DSI (General Directorate of State Hydraulic Works), the total amount of water discharged from the spring during each year was calculated. Then, the discharge coefficient for each dry period was determined separately using the 'Maillet Formula' (Maillet 1905) and the arithmetic average was calculated, shown in the Hydrology section. Using the discharge coefficient, the dynamic reserves of the spring at the end of each period of successive years were calculated using the formula V(t) = Q(t)/α, and the change in dynamic reserve was determined from the difference between these reserves. ...
... The flow regimes of some large springs discharging from karst aquifer systems can be analyzed using discharge hydrographs. The Maillet (1905) formula, a widely-used exponential equation, Content courtesy of Springer Nature, terms of use apply. Rights reserved. ...
... is an example of an analytical solution for porous media (Dewandel et al. 2003). Maillet (1905) proposed that the flow from a spring is related to the amount of water stored in the aquifer (Milanovic 1981;Ford and Williams 2007). Even though the formula was developed for aquifers with grainlike materials, it has also been used for aquifers with cracks and fractures (karst aquifers), which are non-uniform and anisotropic (Bonacci 1993). ...
Karstic landscapes, shaped by water dissolving rocks, are unique ecosystems with complex water systems. Karst aquifers, vital for over 25% of the world’s drinking water, offer a sustainable resource but are vulnerable, such as pollution and over-extraction. Therefore, it’s important to understand the potential and capacity of karst springs in areas suffering from water shortages. Hydrogeological and speleological studies are crucial for understanding the unique characteristics of karst springs. Moreover, epiphreatic caves located near the water table at the interface between vadose and phreatic zones in karst landscapes, hold valuable information about past geological events. By identifying their former presence and location in uplifted limestone regions, we can reveal phases of uplift, lowering of the base level, and the rate of vertical karst development. Consequently, epiphreatic caves and associated karst processes are of considerable interest for understanding past geological changes. Here, we present an integrated study of a spring in the epiphreatic Cokragan Cave, which is an important water resource for the Uşak region, using both speleology and hydrogeology. The complex Cokragan Cave system, stretching over 2050 m, reveals multiple past groundwater levels through its geometry, with elevation differences suggesting tectonic influence. Between 2003 and 2007, Cokragan spring discharged an average of 63.5 million m³/yr, while recharge averaged 62.37 million m³/yr. Measured discharge ranged from a maximum of 1.488 m³/s to a minimum of 0.108 m³/yr. In-situ measurements and analysis of 13 samples revealed the groundwater’s physicochemical characteristics, including major ions such as calcium, magnesium, and bicarbonate, and trace elements such as arsenic, boron, iron, manganese, and zinc.
... Although in recent years new mathematical models have been developed that represent the phenomenon, the models of Boussinesq (1904) and Maillet (1905), both derived from the "theoretical groundwater equations", are still used due to the fundamentals that the they sustain (Darcy's Law and Dupuit-Forchheimer's assumptions in the absence of capillarity above the water table) since they are associated with Specific yield (Sy), Transmissivity (T) and Storage coefficient (Sc) (Dewandel et al. 2003;Rupp and Selker 2005;Rupp and Selker 2006;Yeh and Chang 2013;Mishra and Kuhlman 2013). Amit et al. (2002) mentioned that the Boussinesq model assumes a moderate hydraulic gradient, homogeneity, isotropy and a one-dimensional flow; the Maillet model equation represents a theoretical behavior under similar conditions. ...
... The following equations (2 and 3), used in the present study, are the expressions of the modified Boussinesq (1904) and Maillet (1905) models, respectively: ...
... The estimation, by means of non-linear regression, of the α parameters of both, the modified Maillet (1905) and Boussinesq (1904), models was carried out with the EXCEL SOLVER tool. This allowed the implementation of the calculation equations of the statistical criteria to choose the appropriate model that best represents the conditions of the Yucatan aquifer, studied, as well as the equations to perform the hypothesis tests that allow comparison of the estimates of the parameters of the models; in particular parameter α, of greatest interest in hydrological interpretations (Fiorillo 2016;Patnaik et al. 2018;Shamsi et al. 2019). ...
A number of models exists to analyze discharge recession curves (RC), such as Boussinesq (BM) and Maillet (MM) models, which were derived from theoretical equations of groundwater flow. This paper presents the results of a study, analyzing water table recession curves, whose objective was to determine the model that best represents the dynamics of the karst aquifer in the northern plain of Yucatan, Mexico. The above was achieved defining statistical criteria to select the model; implementing a statistical analysis strategy to compare the estimates of the parameters of greatest hydrological interest of the chosen decay models. Two scenarios were considered for the analysis: I.- Two wells with the same time intervals with standardized data of: different initial hydraulic head (ho); similar ho; modified ho. II.- A single well, starting from an established hydraulic head and discharge in the same period of time. Numerical methods were used to fit models to the observed RCs and a maximum likelihood function for parameters estimation. Statistical criteria were established to choose the best model. The Boussinesq model proved to be the most appropriate, whose estimates of the parameter α were explored, using fixed values of the parameter n. The comparison between the estimates of α was made based on hypothesis tests (t to compare between two values of α and F for the comparison between more than two values of α). Quasiprobability distributions obtained by a maximum likelihood estimator were also used. The best estimates of α(BM) are obtained with values of the parameter n between 0.5 and 2.
... Un serbatoio che si svuota seguendo la (6.1.1) è un serbatoio lineare; per un serbatoio di questo tipo, l'esaurimento nel tempo è descritto dalla ben nota equazione di Maillet (MAILLET, 1905): ...
... Il coefficiente α, in termini idrogeologici e con alcune assunzioni semplificative, ha il seguente significato (MAILLET, 1905;BERKALOFF,1967;KIRÁLY & MOREL, 1976a, 1976bKIRÁLY, 1998aKIRÁLY, ,1998bKIRÁLY, , 2002: ...
... Per individuare, fra tutti i periodi recessivi, l'andamento più rappresentativo del meccanismo di recessione è necessario considerare i periodi in cui non vi sono ricariche ritenute significative. In particolare, dopo vari tentativi con le funzioni diMaillet (MAILLET, 1905) e diTison (TISON, 1960), il sistema di Scirca è stato studiato con l'equazione di Maillet che meglio interpola le fasi di esaurimento. Dalle analisi effettuate risulta che i periodi maggiormente significativi sono stati registrati negli anni: ...
One of the techniques which are used to increase the water yield of springs during droughts, is the drilling of wells upstream or downstream the springs (BONI, 1968; CELICO, 1982; BONI & PETITTA, 1994). This technique implies low well efficiency, high drawdowns, high cost of withdrawals and it can lead to spring drainage. In this work a finite difference mathematical model of the Scirca spring (Umbria - Marche Apennines) was developed, which allows to simulate the effects of pumping wells located at different distances from the spring; the model was built by means of the modflow code (MCDONALD & HARBAUGH, 1984), using the porous equivalent
approach (ANDERSON & WOESSNER, 1992; ANGELINI & DRAGONI, 1997; SCANLON ET ALII, 2003).
The only input parameter for the model is the aquifer recharge, which tends to nil during the dry season, when effective rainfall is very low. The implemented model is able to simulate both the spring discharge during recession, and the variations of daily discharges, continuously measured from 1996 to 2011. Due to the lack of piezometric data and of direct measurements of hydrogeological parameters (hydraulic conductivity and effective porosity), it has been necessary to
run different simulations in order to obtain a set of Trasmissivity and Specific Yield values able to reproduce the average recession curve of Scirca spring. Afterwards a process of “inverse modelling” (DOHERTY, 2000; CARRERA ET ALII, 2005; HILL & TIEDEMAN, 2007) was performed to estimate, by means of calibration, the daily recharge of the hydro-geological system of Scirca spring throughout
several years. In order to investigate the degree of correlation between daily rainfall and simulated recharge, the two time series data sets had undergone MA Analysis; this kind of analysis allowed to “clean up” the data from the influence of short precipitations close to each other, and to highlight a periodic, similar and in phase trend of rain and recharge. An absolute maximum of recharge in the
fall-winter period and a relative maximum in the spring season, were detected. Finally, the efficiency of the management schemes was evaluated by simulating the reaction of the spring, in terms of discharge, to different pumping scenarios; in every scheme the total withdrawal (spring + well) during summer was much larger than the natural spring discharge. The wells were located at different distances from the spring (maximum 2850 m, minimum 100 m), the pumping time span was fixed to 90 days, and 3 pumping rate were used (60, 90, 120 l/s). Results show that the maximum discharge for which the drainage of the spring is avoided and the minimum vital flow (MVF) is guaranteed is 90 l/s. The higher water volumes extracted during summer are balanced by a lowering of the maximum natural discharges. Simulations indicate that, by drilling pumping wells
far from the spring, it is possible to optimize the efficiency of the whole system in terms of total withdrawal, drilling and management costs, and to reduce the environmental impact. According to the model, for the Scirca system, the optimum distance of a pumping well from the spring is 2850 m, whereas the optimum pumping scheme is a discharge of 90 l/s, running three months a year
(June, July and August). The mathematical model shows that the Scirca hydrogeological system needs 625 days to restore its “undisturbed” state, with a tolerance of 0.5 l/s. The model highlights the possibility to force the system to supply a lower amount of water in winter, with the aim to increase the summer yield. Such a management scheme can be of use to better meet the water demand during dry seasons.
... Donc, les courbes de décroissance, qui expriment la relation entre le débit et le temps en régime non influencé par les précipitations, sont des exponentielles décroissantes [16]. En manque de toute connaissance précise des configurations des aquifères du bassin étudié, la fonction utilisable se résume à la formulation de Maillet [17] : ...
... Le choix des valeurs de tarissements est une question difficile, en particulier dans les aspects liés à la détermination du débit débutant la phase de tarissement, qui forme la limite entre le ruissellement superficiel et souterrain. L'étude statistique nous permettra d'évaluer les lois fondamentales appliquées au tarissement dans le bassin de la Tassaout (amont du Barrage Moulay Youssef), en justifiant l'utilisation de la loi Maillet [17], qui s'intéresse particulièrement aux méthodes de sélection des phases de tarissement. Le climat semi-aride, qui caractérise le domaine d'étude, constitue une circonstance préférentielle pour déterminer ces phases, qui apparaissent fréquemment au cours de chaque année. ...
... linéaire et d'obtenir la relation de proportionnalité selon l'Équation (2)[17] := (2)Mohamed CHAKIR et al. ...
Les changements climatiques et les activités humaines ont affecté les équilibres environnementaux dans le monde entier. Le bassin versant de l'oued Tassaout (Amont du barrage Moulay Youssef) appartient au domaine montagnard semi-aride, caractérisé par des précipitations modérées. Par ailleurs, l'eau est au centre des enjeux économiques et sociaux dans le bassin versant (agriculture, eau potable, tourisme, etc.). En raison de la surexploitation, les ressources en eau deviennent de plus en plus fragiles. Ce travail présente une méthodologie d'évaluation quantitative des ressources en eau dans le bassin versant pendant les périodes de basses eaux. L'objectif de cette étude est de connaitre les facteurs qui les régissent les écoulements durant ces périodes dans le but d'améliorer la gestion de ces ressources. Dans cette étude les données hydrométriques de deux stations ont été utilisées : Tamsemat en aval et Ait Tamilil en amont du bassin pour la chronique (1978-2016). La méthodologie adoptée se base sur la détermination et l'analyse des phases de tarissement à partir de l'extraction des coefficients de tarissement. Nous avons adopté la méthode des courbes séquences qui se base sur un algorithme posant les deux conditions relatives à la définition du tarissement : sélectionner des débits décroissants consécutifs et des débits non influencés par les précipitations. En effet, pendant les périodes de tarissement le débit des cours d'eau correspond par définition uniquement au débit de nappe. Les résultats ont montré de forte potentialité des aquifères en amont du bassin. L'alimentation souterraine assure la pérennité régulière de l'oued de Tassaout pendant les périodes d'étiage. Cependant, l'aval du bassin est caractérisé par une moyenne potentialité, ainsi, les ressources en eau sont fortement affectées par les activités humaines. Mots-clés : Bassin versant de la Tassaout, tarissement, extraction, basses eaux, alimentation souterrain.
Abstract Extraction and Analysis of the depletion phases : application in the Tassaout basin (upstream of the Moulay Youssef Dam), Central High Atlas, Morocco (1978-2016) Climate change and human activities have affected environmental balances worldwide. the Tassaout basin (Upstream of the Moulay Youssef dam) belongs to the semi-arid mountainous domain, characterized by 130 Afrique SCIENCE 22(2) (2023) 129-141 Mohamed CHAKIR et al. moderate rainfall. In addition, water is at the center of economic and social issues in the basin (agriculture, drinking water, tourism, etc.). Due to overuse, water resources are becoming increasingly fragile. This work presents a methodology for the quantitative assessment of water resources in the watershed during periods of low flow water. The objective of this study of these flows is to know the factors which govern the flows during these periods with the aim of improving the management of these resources. In this study, hydrometric data from two stations were used : Tamsemat downstream and Ait Tamilil upstream of the basin for the chronicle (1978-2016). The adopted methodology is based on the determination and the analysis of the depletion phases from the extraction of the drying coefficients. We have adopted the method of sequence curves which is based on an algorithm setting the two conditions relating to the definition of the depletion: to select consecutive decreasing flows and flows not influenced by precipitation. In fact, during periods of drying up, the flow of the rivers corresponds only to the flow of the groundwater. The results showed high potential of the aquifers upstream of the basin. The underground supply ensures the regular continuity of the Tassaout river during periods of low water. However, the downstream of the basin is characterized by an average potentiality, thus, water resources can be strongly affected by human activities.
... El coeficiente de agotamiento (α) se obtuvo; despejado α y aplicando logaritmo común en base 10 a los modelos exponenciales y potenciales presentados en la Tabla 2. Es muy importante determinar un rango de valores del coeficiente de agotamiento que permita calibrar los modelos hidrológicos para el río Jequetepeque. Este coeficiente debe cumplir el requisito dado por Maillet (1905), que α >0. ...
... Fórmula (Maillet, 1905) Q La fórmula planteada para la simulación fue: ...
... (Brutsaert & Nieber, 1977). La correlación entre las variables de caudales observados y simulados está controlada por el coeficiente de agotamiento Maillet (1905). ...
The research proposes a hydrological model to forecast recessive flows and it estimates a depletion coefficient for the "Jequetepeque" river, water from the top of the "Gallito Ciego",Contumazá, Peru. Recessive flows were used from the third break point of the flow hydrograph of the "Yonán" station of the "Jequetepeque" river, period 1988-2019. An exponential category hydrological model (ALVI) was used. Ranges of depletion coefficients 0.0148 < α < 0.0003 day-1, and a calibration coefficient of 0.005 day-1were identified. The proposed model, ALVI, was validated, and it is based on statistical indicators, such as: NS (0.84), RMSE (0.62), R2(0.97), EEE (0.66) and IWM (0.84). The statistical indicators indicated a high degree of efficiency, it isinside within the metric of the ranges of the statistical indicators. The hydrological model (ALVI) was validated: Qb=Q0 / (1+e [1.32*Ln ((Q0/Qf) -1)-(0.00049*Ln(A)+0.0057)*t]). The observed and simulated flows were identical tothe non-parametric Mann-Whitney U test. The RStudio Cloud program was used with a significance level of 0.05, it was determined from the median that the observed and simulated flows are similar or identical.
... The earlier stages of baseflow recession usually deviate from the simple exponential formulaof Maillet [49]. Forkasiewitz and Paloc [50] realized that the decreasing limb of hydrograph peaks can usually be decomposed into several (usually three) exponential segments. These authors introduced the concept of hydrograph decomposition. ...
... decomposition, exponential terms are fitted on the flattest section of a spring hydrograph and are successively subtracted from the residual hydrograph ( Figure 2). Forkasiewitz and Paloc [50] assumed that different segments of a spring hydrograph peak represent different parallel reservoirs, all contributing to the discharge of the spring. ...
... This simple but effective model can be described by defining the hydraulic parameters of the low-permeability matrix, the hydraulic parameters of the conduit system, the conduit spacing, and the spatial extent of the aquifer. Forkasiewitz and Paloc [50] assumed that different segments of a spring hydrograph peak represent different parallel reservoirs, all contributing to the discharge of the spring. ...
This study describes a novel methodology for the prediction of spring hydrographs based on regional climate model (RCM) projections, with the goal of evaluating climate-change impact on karstic-spring discharge. A combined stochastic–analytical modeling methodology to predict spring discharge was developed and demonstrated on the Bukovica spring catchment at the Durmitor National Park, Montenegro. As a first step, climate model projections of the EURO-CORDEX ensemble were selected; and then bias correction was applied based on historical climate data. The regression function between rainfall and peak discharge was established by using historical data. Baseflow recession was described by using a double-component exponential model, where hydrograph decomposition and parameter fitting were performed on the Master Recession Curve. Rainfall time series from two selected RCM scenarios were applied to predict future spring-discharge time series. Bias correction of simulated hydrographs was performed, and bias-corrected combined stochastic–analytical models were applied to predict spring hydrographs based on RCM-simulated rainfall data. Both simulated climate scenarios predict increasing peak discharges and decreasing baseflow discharges throughout the 21st century. The model results suggest that climate change is likely to exaggerate the extremities both in terms of climate parameters and spring discharge by the end of the century both for moderate (RCP 45) and pessimistic (RCP 85) CO2 emission scenarios. To investigate the temporal distribution of extremities throughout the simulated time periods, the annual numbers of flood and drought days were calculated. Annual predicted flood days show an increasing trend during the first simulation period (2021–2050) and a slightly decreasing trend during the second simulation period (2071–2100), according to the RCP45 climate scenario. The same parameter shows a stagnant trend for the RCP 85 climate scenario. Annual predicted drought days show a decreasing trend both for the RCP 45 and RCP 85 climate scenarios. However, the annual number of drought days shows a large variation over time. There is a periodicity of extremely dry years with a frequency between 5 and 7 years. The number of drought days seems to increase over time during these extreme years. The study confirmed that the applied methodology can successfully be applied for spring-discharge prediction and that it offers a new prospect for its wider application in studying karst aquifers and their behavior under different climate-change scenarios.
... Par exemple, le ruissellement de surface, qui se situe entre le début de la crue et le pic de crue, est relativement chargé en MES issues de l'érosion physique des sols, ainsi qu'en sodium et chlorure apportés par les précipitations . (Probst, 1983;El Azzi, 2012) en utilisant la loi de Maillet (Maillet, 1905), et d'autre part, en utilisant les concentrations en éléments dissous et particulaires (Pinder and Jones, 1969;Idir et al., 1999) ou les isotopes stables de l'eau (Mcdonnell et al., 1990;Laudon and Slaymaker, 1997;Ladouche et al., 2001) dans un modèle de mélange à différents réservoirs. ...
... Cette séparation basée sur la loi de Maillet (Maillet, 1905) nous a permis d'identifier les différents coefficients de récession ou de tarissement (α) (Maillet, 1905;Mangin, 1975a) (Maillet, 1905;Mangin, 1975a) (Maillet, 1905;Mangin, 1975a (Ulrich et al., 1998). Ces derniers sont très fréquents dans les régions du sud-ouest de la Méditerranée, y compris la partie sud de la ...
... Cette séparation basée sur la loi de Maillet (Maillet, 1905) nous a permis d'identifier les différents coefficients de récession ou de tarissement (α) (Maillet, 1905;Mangin, 1975a) (Maillet, 1905;Mangin, 1975a) (Maillet, 1905;Mangin, 1975a (Ulrich et al., 1998). Ces derniers sont très fréquents dans les régions du sud-ouest de la Méditerranée, y compris la partie sud de la ...
Karst hydrosystems are very sensitive environments to anthropogenic activities (AA) and hydroclimatic variations, such as those caused by Climate Change (CC). Within the Critical Zone (CZ), these environments are the most reactive and the most vulnerable to these forces, which can alter the rapid internal transfer of dissolved elements, including contaminants. These karst systems are therefore excellent candidates to study the impact of CC and AA on water resources and on biogeochemical cycles of elements, especially C and S, strongly disturbed by land use changes, as well as by atmospheric deposition linked to AA (acid deposition). The objective of this thesis is therefore to understand the hydro-biogeochemical functioning of karst systems in temperate environments and to identify the impact of CC and AA. These questions were addressed at different spatial and temporal scales in the Baget karst watershed (BC, Ariège Pyrenees, forest basin, multilithological and quasi-pristine) and in about twenty other karst watersheds at the regional scale (Pyrenees and Massif Central). These basins have a robust database for studying their hydrogeochemical response to these impacts in the long or medium term. In BC, since the 1970s, hydroclimatic (precipitation, temperature, discharge), hydrochemical (major elements) and isotopic (13C, 34S) monitoring has allowed: (i) to identify and quantify the contribution of atmospheric, biological, anthropic and lithological sources to the fluxes of dissolved elements exported by the river; (ii) to determine the main environmental factors controlling the concentration and fluxes of dissolved elements exported by the river, such as lithology, drainage, epikarst, temperature and land use; (iii) establish the dissolved and particulate matter balance, the intensity of mechanical and chemical erosion, and the consumption of CO2 by chemical weathering of rocks and; (iv) highlight in-stream mechanisms such as calcite precipitation and CO2 outgassing, through the innovative development of 13CDIC-based mixing diagrams. In addition, the high frequency analysis allowed: (i) to identify the importance of the different types of flows (quick-response, subsurface and baseflows) on water quality; (ii) to establish a typology of floods according to their nature, intensity and element behavior; (iii) to quantify the importance of major hydrological events on the total annual fluxes of suspended solids (90%) and elements in solution (>50%) for less than one third of the time of the year. The evolution of major element concentrations in the BC is globally comparable to the trends observed in the Pyrenees (5 basins studied) and the Massif Central (15 basins). The increase in Ca+Mg (+5 µeq.L-1.yr-1) and alkalinity (+9 µeq.L-1.yr-1) in the BC drainage water over the last 40 years is statistically linked to the increase in temperature (+0.03 °C.yr-1), the decrease in flow (-4 L.s-1.yr-1) and the closure of the environment (recovery of the forest by +0.05 Km2.yr-1). This quantification was made possible by determining an original indicator of landscape evolution by image analysis since the 1940’s. Moreover, the decrease in sulphates (-2.2 µeq.L-1.yr-1) in the rivers reflects the decrease in acidic atmospheric deposition observed in French rural areas. This continuous decrease suggests that the destocking of sulphur from the soils, originating from acid atmospheric inputs, is still occurring today.
... This study aimed to comparatively evaluate the applicability of automated recession selection procedures to the late-time recession analysis of karst spring hydrograph. For the comparative evaluation of the three automated recession extraction methods (Vogel Method, Brutsaert Method, and Aksoy and Wittenberg Method), we quantified the late-time recession parameters of spring hydrographs by combining three extraction methods with four recession analysis methods (Maillet, 1905;Boussinesq, 1904;Coutagne, 1948;and Wittenberg, 1999). By applying our experimental design into the five karst springs located in Austria, we identified the possible weaknesses of the automated recession extraction procedures for the late-time recession analysis for spring hydrographs. ...
... To achieve so, we applied three automated recession extraction methods (REMs), which are specifically developed to characterize the baseflow characteristics of the streamflow hydrographs. By coupling these three REMs -Vogel; Brutsaert; and Aksoy and Wittenberg Methods -with four recession analysis methods (RAMs) - Maillet (1905); Boussinesq (1904); Coutagne (1948); and Wittenberg (1999) Methods -we comparatively evaluated the applicability of each procedures for the estimation of the late-time recession parameters of each karst springs. Doing that, we simultaneously examined the variations in the range of recession parameters in response to the applied recession extraction procedure. ...
... The REMs procedures are the Vogel Method (Vogel & Kroll, 1992); Brutsaert Method (Brutsaert & Nieber, 1977;Brutsaert, 2008), and Aksoy and Wittenberg Method (Aksoy & Wittenberg, 2011). After the extraction of each recession segment from the 10-year data record, four RAMs including Maillet (1905); Boussinesq (1904); Coutagne (1948); and Wittenberg (1999) were applied to the hydrographs for the estimation of the late-time recession parameters. Then, we compared each parameter estimation procedure by referring to the different combinations of REMs and RAMs. ...
Recession Curve Analysis is a common method to characterize karstic aquifers and their discharge dynamics. Although this technique provides crucial information on quantifying system hydrodynamic properties, the manually selected recession curves analysis is neither a practical technique to cover all candidate recession curves, nor it allows extracting the entire hydrological diversity of the recession behavior. This study aimed to comparatively evaluate the applicability of automated recession selection procedures to the late-time recession analysis of karst spring hydrograph. For the comparative evaluation of the three automated recession extraction methods (Vogel Method, Brutsaert Method, and Aksoy and Wittenberg Method), we quantified the late-time recession parameters of spring hydrographs by combining three extraction methods with four recession analysis methods (Maillet, 1905; Boussinesq, 1904; Coutagne, 1948; and Wittenberg, 1999). By applying our experimental design into the five karst springs located in Austria, we identified the possible weaknesses of the automated recession extraction procedures for the late-time recession analysis for spring hydrographs. To explore the value of the karst spring’s physicochemical data (electrical conductivity and water temperature) as a completion data for the recession curve analysis, we carried out the hydro-chemograph analysis to examine the recession time and its duration. The research provides a research direction as to how the automated recession extraction procedures for the karst spring hydrographs could be improved by the physicochemical signatures of karst springs.
... Conduit flow is represented by α 1 , fracture flow is represented by α 2 , and matrix/ baseflow is represented by α 3 . Although the Maillet (1905) equation was formulated for use in more homogenous aquifers with high porosity and was designed to be applied to recessions as a whole, it can be applied as "microregime analysis" to complex aquifer systems with heterogeneous storage and discharge flow paths (Jones et al. 2018;Kresic and Stevanovic 2010). ...
... peaks) were analyzed using a modifiedMaillet (1905) equation, solving for the recession coefficient: ...
Better characterization of the water resources of the Grand Canyon National Park (GRCA) and World Heritage Site, USA, will inform management decisions regarding a proposed water supply intake from Bright Angel Creek (BAC) and will inform the associated forecasts on water security related to climate change and the impact on spring-dependent species. Characterization of the water supply for GRCA was improved through multiyear hydrograph analyses at five springs discharging from the Redwall-Muav (R) aquifer: Roaring Springs, Emmett Spring, At Last Spring, Tapeats Spring, and Abyss River Spring. Comparison of snowmelt response timing and mean recession coefficients among the five springs show no significant differences, indicating similar timing of snowmelt-related discharge and flow regimes across 50 km of horizontal and 1,000 m of vertical distance through the aquifer system. The mean water volumes discharged during snowmelt and the mean annual discharge are significantly different between Roaring Springs, Emmett Spring, Tapeats Spring, and Abyss River Spring. Linear regression analyses indicate no annual trends in any of the evaluated aquifer characteristics for any spring, except for more stable baseflow between recessions at Tapeats Spring. Water budgets calculated for Roaring Springs are imbalanced, suggesting missing outflow components, a need to refine the recharge region through dye trace studies, and inaccurate precipitation and evapotranspiration data, requiring model improvement. Continued hydrograph comparisons, trend analyses, and water budgets for additional years and springs will be useful for future groundwater modeling and for forecasting impacts on the R aquifer.
... If, after this reduction, a segment 240 consisted of less than five data points, the segment was excluded from further analysis. Through the point cloud of the remaining elements of all remaining segments an exponential curve (nonlinear reservoir) was fitted, as suggested by Maillet (1905): ...
Low flows in the Swiss Plateau are expected to occur more often, to last longer and, hence, to be more severe under climate change. To predict and manage such periods of water scarcity effectively, more precise information on the drainage behavior of catchments is required. The drainage behavior of a catchment can be characterized by recession analysis methods (RAMs; e.g., recession curves) of which several have been developed in the last decades. Their recession parameters have been related to different aquifer characteristics or more general catchment characteristics like lithology, topography, or climatology. Such parameters vary widely, and the effects of uncertainties on the model’s outcomes are diverse and complex. Despite the obvious potential of recession curves for prediction, they have so far not been used for operational low flow prediction and guidance for hazard mitigation. In addition, recession curves of slowly draining catchment states are hardly represented by current RAMs. To fill the gap of RAMs representing slow draining catchment states we developed two novel RAMs, one fully automated and based on the matching strip method (MRC_slow), the other one (SDSC) relying on a careful expert-based selection of few recession segments with the slowest recession behavior. Alongside we used three established RAMs from the literature (one further matching strip model, linear regression and lower envelope in the discharge decay – discharge recession diagram). We applied the five RAMs on previously extracted low flow segments of 33 catchments in the Swiss Plateau and compared them on their recession curvatures, durations, and volumes. We designed a procedure that evaluates which of any selected RAMs best matches the recession behavior of individual low flow segments of a hydrograph. Applying this in a simulated prediction situation, we evaluated in retrospect, which of the five specifically selected RAMs predicted the low flow hydrographs between 2021 and 2022 most accurately. We found the variability of recession durations and volumes between catchments to be higher than between the five RAMs. Within 30 of the 33 catchments, the order of recession durations and recession volumes was the same. Hence the different recession behaviors of the RAMs could be related to different catchment states. Upon evaluating the low flow predictions, we found that the MRC_slow approach overall performed best followed by linear regression and SDSC. However, for operational low flow prediction we recommend using four of the five RAMs. This allows for changing the recession model(s) at every timestep if the recession behavior changes. It is also possible to present predictions with a model ensemble, indicating a range of uncertainties if several models perform similarly well. The described data-driven approach and the newly developed models are, therefore, very promising for improving low flow predictions in gauged catchments.
... The parameter α P has the dimension [T −1 ] and expresses the drainage characteristics of the Poiseuille reservoir. Equation (16) represents Maillet's formula [17], and the constant α P is known as the recession coefficient, which controls the exponential decay of the discharge with time. ...
Analytical solutions for turbulent and laminar water flow conditions are developed considering the drainage process of a simple tank reservoir, using the Darcy–Weisbach and the Poiseuille laws, respectively. Near the critical value of the Reynolds number, the Darcy–Weisbach and the Poiseuille laws do not match, and there is a gap regarding the possibility of describing the drainage analytically. This gap corresponds to the critical zone of the Moody diagram, where theoretically a constant discharge occurs under a decreasing hydraulic gradient. In the critical zone, this hydraulic behavior of the flow reflects the different energy losses occurring during the drainage, as the laminar flow is a more efficient flow condition than the turbulent one. In natural systems (e.g., springs and karst aquifers), a smooth transition from the turbulent to the laminar water flow occurs due to the heterogeneity in the medium.
... In regular situations without any notable 195 meteorological events, a linear interpolation method was employed to reconstruct the missing data. If the data loss occurred immediately after a precipitation event, a typical recession curve equation (Maillet, 1905) was used: ...
In the Central Eastern Alps, an increasing number of high-altitude streams display high concentrations of toxic solutes such as Al, F-, Mn, and Ni that may strongly exceed drinking water limits. Previous studies have shown that these elements are mobilized from rock glaciers occurring at the origin of the streams. This is caused by the weathering of pyrite producing sulfuric acid and therefore promoting the leaching of these elements from the crystalline host rocks. After mobilization, the elements are temporally stored and enriched in the rock glacier ice. Today, the climate-change-induced accelerated melting of rock glaciers thus leads to a quick and focused export in summer when ice melt export rates are high. The temporal storage of mobilized elements in the rock glacier ice opens up the opportunity to use the strong chemical signal in the streams to track rock glacier melt dynamics and to identify the governing processes controlling the export of ice melt. To test this and to assess the consequences of accelerated rock glacier melt on streamwater quality, here we present a two-year dataset (2021, 2022) of monitoring a high-alpine stream originating from an intact rock glacier located in Eastern Switzerland. The monitoring includes monthly sampling and discharge measurements at the rock glacier outlet, as well as continuous tracking of the geogenic fluxes of toxic solutes using a pressure and conductivity probe. Our monitoring revealed high annual fluxes with strong seasonal variation, whereby the fluxes were highest during the warm summer months. In 2021, the annual fluxes were up to several tons each, which is remarkable given that the area of the rock glacier covers only about 40’000 m2. Interestingly, in 2022 the fluxes were about 30 % lower despite the record-high summer temperatures. A similar difference was observed for the annual discharge recorded for the two years. This suggests that the export of both ice melt and toxic solutes are strongly controlled by the amount of water from snowmelt and precipitation infiltrating into the rock glacier system. The dry weather and low discharge rates in 2022 thus likely lead to lower export rates compared to 2021, when snow height and precipitation rates were above average. Nevertheless, in both monitoring years the degradation of the rock glacier significantly contributed to the discharge of the downhill stream. Based on these aspects, we present conceptual models for accumulation of toxic solutes in rock glacier ice well as for their water driven mobilization during accelerated rock glacier degradation. Finally, we argue that monitoring solute fluxes exported from rock glaciers is a promising future research direction for obtaining more reliable estimates of the amount of ice melt exported from rock glaciers.
... where b k is derived from b kÀ1 multiplied by alpha (notice that in the referred manuscript this parameter is defined as 'a', but in the R function is computed as 'alpha', nomenclature that we decided to keep in the manuscript). This might lead to confusion, since the recession constant in hydrogeological literature is usually presented as α, and defined as in the following equation (Maillet 1905;Zhu et al. 2010): ...
Hydrological models can benefit from soft calibration, a process by which the proper simulation of hydrological variables is proved while or before addressing hard calibration. Soft calibration reduces the probability of obtaining a statistically accurate but unrealistic model. However, it requires soft data, which is often hard to acquire or unavailable. This work presents HydRoVars, an R tool developed to facilitate the estimation of data which can be implemented in a soft calibration procedure. It allows to estimate two key hydrological indices (the runoff coefficient and the baseflow index) and weather-related variables at the catchment scale for one or numerous basins. The runoff coefficient is calculated automatically from precipitation and streamflow datasets. Groundwater contribution is estimated through a semi-automatic process based on a baseflow filter which considers hydrogeological properties. Modellers would benefit from incorporating soft calibration in their calibration procedures, and this tool might help to estimate these relevant hydrological variables in their modelled area. The tool has been tested in 19 subbasins of the Tagus River basin (Spain) located in different geological regions. In the test cases, we demonstrate the usefulness of this tool to improve the model representation and gain an understanding of the catchments' hydrology.
... where, Q (t) is discharge at time t, ψ (t) is the quick flow, and φ (t) the baseflow segment (Padilla et al., 1994). The base flow recession follows Equation (2) from Maillet (1905): ...
Karst aquifers consist of complex networks of conduits in which groundwater flows and recharge/discharge processes are generally more dynamic than in other types of aquifers. Due to their intrinsic heterogeneity and anisotropy, monitoring, quantifying, and analysing natural responses of karst springs is an efficient tool. Unlike Cenozoic and Mesozoic rocks, in Neoproterozoic karst systems, groundwater circulates and stores generally in dissolution features known as tertiary porosity, as the rock's primary porosity is recrystallized, considered negligible. This article studies the hydrodynamics of a karst portion of the São Miguel River basin, southwest of the state of Minas Gerais, Brazil. The region is predominantly composed of Neoproterozoic carbonate rocks, dating from about 570 to 540 million years ago. During a hydrological year (2019–2020), three karst springs (S1, S2, and S3) were daily monitored through their natural responses (variations of electrical conductivity, EC, temperature, T, and discharge, Q) to rainfall episodes. The data were interpreted based on the analysis of spring hydrographs, time series, recession curves (seasonal and intra‐annual), and statistics of EC, T, and Q variations. The results show the three springs generally exhibit quick flow, typically karstic, in the case of hydrosystems with a well‐structured and functional underground drainage network. The time series indicate the hydrosystem drained by S1 presents slower circulation and a lower degree of linearity, resulting from the higher sinuosity of the system, while the hydrosystems of S2 and S3 have similar behaviours, of quick water circulations immediately after a rainy episode. The degrees of karstification classify S1 and S2 as complex and extensive karst systems consisting of several subsystems, and S3 as a system in which the conduit network is more developed at the upper epiphreatic zone than near the outlet.
... where Q t is the discharge at time t, Q 0 reveals the discharge at the initial time, and α is a recession coefficient (Maillet 1905). Based on the HSP5B spring recession curve, during the α micro-regime, the spring discharge decreased from 0.2 to 0.15 l/s over 6 months (from April 2019 to October 2019). ...
This research aimed to determine the origin of ions and the type of flow system in groundwater flowing out through two types of atmospheric and hydrothermal springs by hydrochemical and hydrodynamic approaches in a volcanic aquifer. The indings revealed that the major ion types in atmospheric waters are calcic and magnesium bicarbonate, whereas hydrothermal springs predominantly have a chloride-sodic composition. It shows an evolving pattern resulting from the mixing of hydrothermal and atmospheric waters. Investigating the ionic ratios and the saturation index helps to determine the origin of ions, which suggests that the presence of ions in the waters can be attributed to the weathering of silicates and plagioclase-bearing minerals in the volcanic units and the ionic exchange in some cases. The results of the recession curve analysis revealed a predominance of conduit flow with α = 0.144 in the system feeding the representative hydrothermal spring. Two micro-regimes with α1 = 0 = 0.46 and α2 = 2.68 were detected on the hydrograph of the atmospheric representative spring, which indicates the development of systems with two types of flow regimes. The Qmax/Qmin ratio for selected hydrothermal and atmospheric springs was 2.3 and 36.8, respectively, and the calculation of the electrical conductivity coefficient confirmed the result of rescission curve analysis, with values of 11% for hydrothermal springs and 18% for atmospheric springs, respectively.
... The definition of baseflow is perceived differently by different authors (Smakhtin 2001;McMillan 2019). The basic idea of separating baseflow (the part of streamflow affected mainly by the water supply in the basin) and stormflow (the part affected by precipitation) has been studied for over a hundred years (Boussinesq 1904;Maillet 1905;Horton 1933); its use has not lost its importance even in recent studies (Xie et al. 2020;Taormina et al. 2015). In forested catchments, baseflow can be understood as runoff of surplus water that the forest stands (plant-soil system) did not physiologically use under standard hydroclimatic conditions (Filoso et al. 2017). ...
We performed a comparative paired catchment study of three headwater upland forest micro-catchments with different forest types in the precipitation-abundant year 2020. The analysis was based on baseflow separation and resulting baseflow index (BFI). The year 2020 was intentionally chosen as a way to reflect the expected effects of climate change in the region where more extreme hydroclimatic events are expected. Our team demonstrated that in case of hydroclimatic extremes, there are significant differences in the runoff response from these catchments, depending especially on the tree species composition in the forest stands. Three forest types with the predominance of European beech (Fagus sylvatica), Norway spruce (Picea abies), and mixed forest were analyzed. The observed different values of BFI were interpreted in relation to the ability of forest stands to retain water and slow runoff in extreme runoff events determined by the stormflow component as an indication of their flood control efficiency. A significantly worse flood control efficiency and an overreaction of runoff response to precipitation events were observed in the spruce catchment. This also suggests that the spruce catchment is more prone to suffer from drought since twice as much water was lost from the system during extreme hydroclimatic events as opposed to the other two with less spruce in the stands and less water is thus available for groundwater recharge.
... The quantitative recession analysis for spring discharge is useful for identifying flow dynamics and aquifer characteristics. One widely used model to analyse spring recession curves is the exponential attenuation method, which was proposed by Boussinesq (1877) and improved by Maillet (1905). Then, Barnes (1939) and Schoeller (1948) suggested using the sum of several (n) exponential segments to decompose the recession limbs (Equation 4). ...
... The quantitative recession analysis for spring discharge is useful for identifying flow dynamics and aquifer characteristics. One widely used model to analyse spring recession curves is the exponential attenuation method, which was proposed by Boussinesq (1877) and improved by Maillet (1905). Then, Barnes (1939) and Schoeller (1948) suggested using the sum of several (n) exponential segments to decompose the recession limbs (Equation 4). ...
The quantitative analysis of karst spring hydrographs aids in characterizing the hydro-dynamic properties of aquifer systems. However, the relationships between spring hydrographs and hydrologic functions of different media lack in-depth research. This study detected the rainfall-discharge processes of covered karst systems using two combined discrete-continuum models (a coupled continuum-pipe model and a hybrid model) developed based on laboratory experiments. An improved exponential function was used to decompose spring recession hydrographs with a great performance, and the results indicate that the slow drainage controlled by the porous medium dominates the whole recession process. There is a shift in the contribution of the matrix to karst discharge systems with the increase of its hydraulic conductivity. Although spring hydrographs have a great dependency on the hydraulic process of fracture networks, the variation in permeability of the matrix significantly changes the storage capacity of fractured rocks and spring discharge behaviours. The changing process of water storage rate of the matrix and fractures with spring hydrographs reveals three stages: a period of steep rise and fall, a period with slight fluctuations, and a gentle descent stage. The parameter sensitivity analysis in both models shows that the covering porous layer has a strong effect on the patterns of karst spring hydrographs, and the specific yield is more sensitive than hydraulic conductivity. While these simulations were conducted at the laboratory scale, the findings provide insights into practical applications of spring protection and water resources management. K E Y W O R D S covered karst system, discrete-continuum approaches, fractured rocks, matrix permeability, numerical simulation, porous medium, rainfall-discharge process, spring hydrograph
... An exponential decrease of flow rate is a well-known characteristic of discharging linear reservoirs (Maillet, 1905;Fiorillo, 2011; Figure 11). These idealized systems comprise a pressurized chamber of fluid and a pathway through which it can exit. ...
Volcano crater lakes, while picturesque, can sometimes mask the occurrence of small eruptions or hydrothermal fluid release events. However, these seemingly hidden events hold a wealth of valuable information about the underlying volcanic conduit and may pose risks to those near the volcano’s summit. This study presents a novel method for identifying these hard‐to‐detect fluid release events by examining seismic data from Ruapehu volcano in New Zealand. We undertake a multi‐timescale template‐matching analysis that uses a newly discovered seismic eruption precursor, to identify patterns related to the rapid consolidation of hydrothermal seals, pressurization processes, and the subsequent release of hydrothermal fluids. As a result, we identified a potential instance of sudden fluid‐release events that were previously unnoticed due to the presence of the crater lake. Our findings support a conceptual model of cyclic pressure variation within the conduit beneath an active crater lake. This model involves the formation and disruption of seals, followed by depressurization through hydrothermal fluid release events. Fluid discharge recession recorded as seismic amplitude decay, provides information about the properties of the reservoir, conduit, and the fluid being discharged. We also applied this technique to Kawah‐Ijen (Indonesia) and Copahue (Chile‐Argentina), identifying multiple potential events at these volcanoes. These findings enhance our understanding of the conditions leading to explosive eruptions, including those that could breach the crater lake.
... For a 5 year warm-up period of the model as well as for the testing period, evaporation data from the GLEAM dataset (Miralles et al. 2011;Martens et al. 2017;Gleam 2021) and precipitation data from MSWEP (multi-source weighted-ensemble precipitation) (Beck et al. 2019;GloH2O 2021) The vadose zone is represented in the model as a linear reservoir. In this simple and commonly used approach, discharge from the reservoir is proportional to the stored water volume in the reservoir (Maillet 1905;Dewandel et al. 2003). ...
The freshwater resource in karst is subjected to both sea level rise and an increasing pressure caused by the high-water demand. Therefore, developing an understanding of the hydrogeological dynamics of the karst aquifer can be a useful tool for improving protection and management actions. Vora Bosco cave (Apulia, Southern Italy) was instrumented with a multi-parameter probe for groundwater level measurements, aimed at exploring the system behavior within the cave recharge area. To characterize and quantify the natural recharge and discharge behavior of the system, a simple reservoir model was developed, initially also with the intention of predicting groundwater dynamics. Based on the original time-series of water level observations, different calibration datasets were established using different split-sample and bootstrapping approaches, and a regional sensitivity analysis was executed. Furthermore, in addition to the original observation time-series, a 3-month extension was used as a model testing period. Using these analyses, the parameters identifiability and the predictions robustness for the model testing period were evaluated. Results reveal that while the calibration on the whole dataset, as well as the bootstrapping approaches, lead to better performances in the calibration and validation period of the original time-series, and to a higher model precision with smaller uncertainty ranges. their performance in the model testing period becomes very poor and the observed water level data no longer plots within the uncertainty bands. Based on this extensive analysis, the model is finally rejected. Our study therefore also confirms the importance of model validation, especially when only a short time-series of observations are available.
... To investigate how the groundwater is stored in the different BA sectors, the hydrographs of the recession periods were examined by using the Maillet equation [77], which allows the depletion coefficient (α) and amount of W0 to be calculated. ...
The combination of several factors related both to human pressure as well as natural issues could lead to a marked alteration of the groundwater budget terms and a decrease in groundwater availability. The basal aquifer of the Sibillini Mts. is a strategic resource of drinking water in the central sector of Apennine (Italy). The seismic sequence that occurred in this area in 2016 induced transient and sustained modifications in the aquifer settings. Springs located on the western side of the Sibillini Mts. were characterized by an increased discharge, while in contrast, the eastern springs suffered an intense drop in their groundwater discharge. In 2017, a drought period started immediately after the exhaustion of the seismic sequence effect. The comparison between the recharge and discharge of the major springs in the 2000-2020 period allowed the definition of the different responses of the aquifer to the co-occurrence of earthquakes and climatic events. The hydrodynamic alteration triggered by the earthquake induced a huge depletion of the groundwater stored in the eastern sector of the basal aquifer (at least 50 × 10 6 m 3). The scarce recharge occurring in the following drought period (more than 30% of the average annual value) was not enough to restore the groundwater resources, causing a serious drinking water supply crisis in the main tapped springs in the eastern sector of the aquifer.
... Consequently, it is possible to hypothesize that the aquifer behaves like a double permeability medium, where the water mainly flows in the macropore/cracks/fissures even if a secondary flow is possible. These assumptions are confirmed by the hydrograph recession analysis (Maillet, 1905). In fact, the semi-logarithmic plot of a single recession segments shows, most of the time, changing in slope, demonstrating that the flow comprises at least two different components. ...
The present work provides new insights on some factors controlling the groundwater flow in low-permeability media affected by deep Apennine landslide, involving several million cubic meters of soil and rock. Rainfall and groundwater circulation are among the major triggers of landslides. However, if the first factor is well studied, only few research deal with the hydrogeological processes in the landslide. Thus, in this study, combined hydrogeological, geochemical and isotopic investigation were performed in order to: (1) characterize infiltration and flow processes and (2) understand the role of sliding surface on groundwater circulation in a complex landslide that mainly involves sandstones and clay materials. Results indicate that at least two circuits coexist: a faster one, where rainfall preferentially infiltrates and flows in a well-connected network of macropores, cracks and soil pipes, which mainly feeds the springs; a slower and a deeper one that flows in the soil matrix and fractures of the landslide body. Moreover, the investigated slip zones show an aquiclude characteristic in terms of groundwater circulation, where the flow is very slow and precipitation influence is negligible. These results could be helpful in an accurate slope stability considerations and to improve the reliability of landslide risk assessment.
... Extreme maximum values or very steep recession limb may indicate high development of karst conduits, i.e., high Karstification degree, (Bonacci 1993;Fiorillo 2014). Even though there are several methods for recession curve analysis (Bonacci 1993;Fiorillo 2011Fiorillo , 2014, Maillet's (1905) exponential equation (Eq. 1) was applied for the recession curve analysis of Mokra and Divljana karst springs: ...
This paper deals with karst aquifer characterization using time series and stochastic analysis and modelling as well as groundwater quality analyses. Such a methodological approach was applied on the eastern Suva Planina Mt. karst aquifer by evaluating data for the period of 2015–2018, which included monitoring and analysis of major karst springs Mokra and Divljana and their quantity and quality parameters. Quantitative characterization of these karst springs utilised for water supply of Niš city, has shown high karstification degree and very well retention capacity of both, Mokra and Divljana sub-systems with slightly lower storativity of the Divljana sub-system. In addition, simulation models have proved that precipitation is the main driving force of the hydraulic behaviour of the karst groundwater circulation and discharge in this area. Qualitative characterization has shown very small variation of chemical parameters, with expected karst groundwater fingerprint, and isotopic analysis confirmed that water replenishment is relatively fast. Results also speculate that these two springs actually represent discharging points of one aquifer that is fragmented into two interconnected sub-systems. The study proves the necessity for karst groundwater characterization to manage this important natural resource in a sustainable way.
... The analysis of hydrographs started mainly after the publication of Maillet (1905). However, continuous monitoring of karst springs really started only since the 1950s. ...
... Recession curve analysis has been widely developed over the past century (Barnes 1939;Boussinesq 1903;Coutagne 1948;Drogue 1972;Horton 1933;Kullman 2000;Maillet 1905;Mangin 1975;Padilla et al. 1994). It consists in calibrating numerical models on a selection of recession curves from a hydrograph and interpreting the parameters of the equations. ...
Karst spring discharge time series analyses are often used to gain preliminary insights into the hydrological functioning of a karst system. KarstID is an R Shiny application that facilitates the completion of such analyses and allows the identification of karst system hydrological functioning. The application permits (i) to perform statistical, recession curves, classified discharges and signal (simple correlational and spectral) analyses; (ii) to calculate relevant indicators representative of distinct hydrological characteristics of karst systems, (iii) to classify karst systems hydrological functioning; and (iv) to compare the results to a database of 78 karst systems. The KarstID software is free, open source, and actively developed on a developer community platform. The user-friendly installation and launch make it especially accessible even for non-programmers; therefore, KarstID can be used for both research and educational purposes. The application and its user manual are both available on the French SNO KARST website (https://sokarst.org/en/softwares-en/karstid-en/).
... período de estiaje donde, de acuerdo con el grado de penetración del río en el acuífero, este es capaz de mantener un determinado caudal debido, exclusivamente, al aporte de agua subterránea. Este puede ser así separado y procesado individualmente aplicando la ecuación general de Maillet (1905), que describe perfectamente el agotamiento de caudales: ...
RESUMEN: Se describe la metodología de cálculo de los recursos de explotación de las aguas subterráneas en el karst de montaña de Cuba, basada en el análisis y procesamiento de las curvas de agotamiento de caudales de manantiales y de los sistemas fluviales autóctonos a partir de la data histórica registrada en las estaciones hidrométricas. La metodología se ha extendido a la cuantificación de variables del campo de propiedades físicas de los acuíferos y a la actividad geoquímica. ABSTRACT: A description of the methodology used to compute the ground water resources of the Cuban mountain karst is described. The methodology, extended to the quantification of the physical variables and the geochemical activity is based in the analysis of the discharge curves of the streams and springs draining the systems during recession and registered at the hydrometric stations.
... during recession may be characterized by an exponential or generalized power-59 law function (Maillet, 1905;Dewandel et al, 2003; Hergarten and Birk, 2007; 60 Kovács and Sauter, 2008; Birk and Hergarten, 2010); the detailed modelling 61 of karst systems is, however, complicated due to heterogeneity, data scarcity, 62 and system non-linearity. ...
Karst aquifers are important sources of fresh water on a global scale. The hydrological modelling of karst spring discharge, however, still poses a challenge. In this study we apply a transfer function noise (TFN) model in combination with a bucket-type recharge model to simulate and predict karst spring discharge. The application of the noise model for the residual series has the advantage that it is more consistent with assumptions for optimization such as homoscedasticity and independence. In an earlier hydrological modeling study, named Karst Modeling Challenge (KMC; Jeannin et al (2021)), several modelling approaches were compared for the Milandre Karst System in Switzerland. This serves as a benchmark and we apply the TFN model to KMC data, subsequently comparing the results to other models. Using different data-model combinations, the most promising data-model combination is identified in a three-step least-squares calibration. To quantify uncertainty, the Bayesian approach of Markov-chain Monte Carlo (MCMC) sampling is subsequently used with uniform priors for the previously identified best data-model combination. The MCMC maximum likelihood solution is used to predict spring discharge for the evaluation period, indicating a superior performance compared to all other models in the KMC. It is found that the model gives a physically feasible representation of the system, which is supported by field measurements. While the TFN model simulated rising limbs and flood recession especially well, medium and baseflow conditions were not represented as accurately. The TFN approach poses a well-performing data-driven grey-box alternative to other approaches that should be considered in future studies.
... Since the data is hourly, monthly moving average values were used to demonstrate a clearer view of the data. Then, recession coefficient calculations performed using the Maillet (1905) ...
In this thesis, Muğla Karst aquifer, discharge points Azmak Springs and Azmak
Stream recharged by these springs were investigated. It is important to make a research
on this aquifer as it is the only groundwater resource in the region and because it has
both ecological and touristic value in the discharge area. In the studies carried out
within the scope of the thesis, geophysical 3-dimensional modeling, time series
analyses and thermal remote sensing with unmanned aerial vehicle were performed by
focusing only on the discharge region. In order to determine the spring conduit
structure, the underground electrical resistivity in the upstream was modeled in 3-
dimension. It is found that some of the springs are being recharged by different
conduits. The water levels of the springs were analyzed by correlation & spectral
methods, and the karst aquifer system in the region was evaluated. It was determined
that the aquifer system has a low level of karstification but high storage capacity. This
might be caused by the complex geology of the region which may have different
karstification levels. In addition, it is found out that the alluvial plains have a great
effect on the karst system. With the aim of the karst discharge investigation, thermal
aerial photographing of the springs and the stream were performed by using an
unmanned aerial vehicle. New discharges were determined in the study area. In
addition, a methodology for collecting data with a thermal camera loaded unmanned
aerial vehicle has been established. This methodology is expected to be useful for
researchers who want to collect data in similar studies.
... More than a century ago, Maillet (1905) suggested the linear reservoir where discharge Q is directly proportional to the stored volume V , 20 Q(t) = αV (t). ...
Understanding the properties of preferential flow patters is a major challenge in subsurface hydrology. Most of the theoretical approaches in this field stem from research on karst aquifers, where typically two or three distinct flow components with different time scales are considered. This study starts from a different concept, where a continuous spatial variation in transmissivity and storavity over several orders of magnitude is assumed. Distribution and spatial pattern of these properties are derived from the concept of minimum energy dissipation. While the numerical simulation of such systems is challenging, it is found that a reduction to a dendritic flow pattern, similar to rivers at the surface, works well. It is also shown that spectral theory can allow for investigating the fundamental properties of such aquifers. As a main result, the long-term recession of the spring draining the aquifer during periods of drought becomes slower for large catchments. However, the dependence of the respective recession coefficient on catchment size is much weaker than for homogeneous aquifers. Concerning the short-term behavior after an instantaneous recharge event, strong deviations from the exponential recession of a linear reservoir are observed. In particular, it takes a considerable time span until the spring discharge reaches its peak. This rise time is in an order of magnitude of one-seventh of the e-folding recession time. Despite the strong deviations from the linear reservoir at short times, the exponential component typically contributes more than 80 % to the total discharge. This fraction is much higher than expected for karst aquifers and even exceeds the fraction predicted for homogeneous aquifers.
... where Q t is the discharge measured at time t, Q 0 is the discharge at the start of recession t = 0 (note that Q 0 is not peak flow Q max ), t is the time elapsed between Q 0 and Q t , and α is the recession coefficient (Maillet 1905). From this equation, the response time t R can be obtained, being t R = 1/α. ...
The study of the occurrence of groundwater, its movement and quality is designated as groundwater hydrology (or hydrogeology). This chapter explains how groundwater moves in different karst settings, and which methods can be used to analyze karst drainage systems. Karst aquifers are groundwater flow systems in which water moves through different types of permeability features: the interconnected primary porosity of the rocks, the fissured system, and the conduit system. Underground water flow in karst is mainly controlled by the hydraulic gradient, with water following the most easily penetrable pathways such as bedding planes and interconnected fissures and pores. To be able to make an estimation of the water budget in a karst aquifer one needs to know the boundaries of the groundwater basin. In most types of aquifers, the hydraulic characteristics of the rock masses are obtained drilling a series of boreholes in which a number of physical tests can be carried out.
... All nine karst flood recession hydrographs were separated into two stages, namely the rapid-flow-drainage stage and the slow-flowdrainage stage, to represent the recessions of a homogeneous and isotropic aquifer as a single exponential decrease (Chang et al., 2015). A simple mathematical model proposed by Maillet (1905) was selected to simulate karst flood recessions in the rapid-flow-drainage stage and the slow-flow-drainage stage, and the model has been expressed as follows: ...
Study region
Hekou karst basin, southwestern China.
Study focus
The duality and complexity of hydrological behavior of karst systems pose challenges in precipitation-streamflow modelling, reliable hydrological models with high temporal resolution are warranted for predicting floods in humid flood-prone karst-dominated basins. This study proposes a grid-based distributed karst Xin’anjiang hydrological model (DK-XAJ), the model structure of each grid was developed using the conceptual Xin’anjiang model. Water exchange among each grid and the spatial heterogeneities of land use types and the karstification in each grid were considered. Information on two new linear reservoirs was added to represent the rapid-conduit and slow-matrix underground flow to improve the karst dual-porosities, the range of the underground runoff partitioning parameter was estimated from the observed flood recessions.
New hydrological insights
The DK-XAJ model demonstrated good successive hourly streamflow modelling performance with mean values of 0.84, 0.83, 0.28, and 0.88 for NSE, KGE, RRE, and R², and results during validation of one nested interior grid without recalibration was also good. The results indicate that the DK-XAJ model can help obtain detailed results for successive streamflow processes, the peaks of floods under different magnitudes and the marked increase and recession of the flash floods can be accurately reproduced and depicted. The DK-XAJ model can therefore be considered a new tool for the prediction of sub-daily precipitation-streamflow and flood events in karst-dominated basins.
... Finally, the daily discharge data that were recorded at St2 were used to study the depletion coefficient throughout the analysed years. The recession periods were determined by fitting the data with the Maillet equation [50]. Several authors working on this area [48,[51][52][53] have shown that this equation is the most suitable to fit the springs recession curves of the Sibillini Mts. ...
Carbonate aquifers are characterised by strong heterogeneities and their modelling is
often a challenging aspect in hydrological studies. Understanding carbonate aquifers can be more
complicated in the case of strong seismic events which have been widely demonstrated to influence
groundwater flow over wide areas or on a local scale. The 2016–2017 seismic sequence of Central
Italy is a paradigmatic example of how earthquakes play an important role in groundwater and
surface water modifications. The Campiano catchment, which experienced significant discharge
modifications immediately after the mainshocks of the 2016–2017 seismic sequence (Mmax = 6.5)
has been analysed in this study. The study area is within an Italian national park (Sibillini Mts.)
and thus has importance from a naturalistic and socio-economic standpoint. The research strategy
coupled long-period artificial tracer tests (conducted both before and after the main earthquakes),
geochemical and discharge analyses and isotope hydrology with hydrogeological cross-sections.
This study highlights how the seismic sequence temporarily changed the behaviour of the normal
faults which act predominantly as barriers to flow in the inter-seismic period, with water flow being
normally favoured along the fault strikes. On the contrary, during earthquakes, groundwater flow
can be significantly diverted perpendicularly to fault-strikes due to co-seismic fracturing and a
consequent permeability increase. The interaction between groundwater and surface water is not
only important from the point of view of scientific research but also has significant implications at an
economic and social level.
... Because of the abundance of groundwater, the influx into the sea is rather continuous, as suggested by ten flow rate measurements taken over expressly for this research in the period 2021/02/18-2021/06/07 (Fig. 4). By applying a simple linear reservoir model to the data (Maillet, 1905) we infer a "mean residence time" of 53 days (dotted curves in Fig. 4) implying the flow rate at the mouth vanishes only after 165 consecutive dry days. ...
Almost 140 years of industrial exploitation have severely degraded the environment of Bagnoli Coroglio (BC), the westernmost neighborhood of the city of Naples (Italy). In this peculiar area, however, geogenic processes overlap with the impact of human activities, making it difficult to distinguish between anthropogenic and geogenic pollution sources. This is particularly true for Arsenic, the concentration of which in the marine sediments largely exceeds the tolerable level for human health and the background value for local pyroclastics.
After several studies have used traditional tools based on multivariate statistics, this article attempts at tackling the problem via numerical modeling, which provides a deeper insight into the physics that governs the pollution process.
Therefore, we use a particle tracking model to assess whether arsenic levels in the seabed can be affected by the influx of thermal water from an artificial channel outfalling at the westernmost part of the coast The climatic forcings that drive the marine circulation are simplified to basic “scenarios”, in which wind and waves are stationary in strength and direction. Since the simulation time is much less than the contamination timescale, the comparison between numerical results and measurements is essentially qualitative and concerns the shape of contamination contours.
It was found the primary forcing that enables seabed pollution is the tidal circulation, which, moreover, acts continuously in time.
Quantitative arguments based on regression analysis suggest the discharge of thermal water explains almost a quarter of the observed pollution, which is consistent with previous research based on multivariate statistics.
... Già alla fine del mese di gennaio 1981, quando l'incremento delle portate indotto dal terremoto si era ormai esaurito è stata effettuata (Celico, 1981a, b) una preliminare previsione dello svuotamento (circa 30×10 6 m 3 ; Fig. 12a) che avrebbe potuto subire l'acquifero carbonatico per effetto della sollecitazione sismica. Il calcolo è stato eseguito ipotizzando (anche sulla base del comportamento assunto dalla sorgente durante il terremoto del 23 luglio 1930) che il decremento delle portate avvenisse secondo un modello matematico molto simile a quello di Maillet (1905) e che l'andamento dell'idrogramma, in condizioni indisturbate, potesse non discostarsi molto da quello dell'anno medio. Lo scarto tra le previsioni effettuate al mese dicembre 1981 e le portate realmente misurate è risultato pari al 20% circa. ...
ACQUE SOTTERRANEE Nel presente lavoro è riportata la sintesi delle attuali conoscenze idrogeologiche quali-quantitative del territorio irpino. La raccolta e l'omogeneizzazione di dati pregressi e l'integrazione con nuove e più recenti acquisizioni, derivanti da attività di rilevamento idrogeologico di campo, hanno consentito di effettuare un'ampia caratterizzazione quali-quan-titativa dei principali acquiferi ricadenti nel territorio irpino. Infatti, nell'ambito di ciascuno di essi sono stati definiti, con differenti gradi di approfondimento, l'assetto idrostratigrafico e idrostrutturale, gli schemi di circolazione idrica sotterranea delle principali falde, le caratteristiche chimico-fisiche delle acque sotterranee, la potenzialità delle princi-pali risorse e la loro attuale utilizzazione. Sono state inoltre analizzate alcune problematiche connesse con la salvaguardia dall'inquinamento di talune risorse ricadenti in aree carbonatiche ed esaminate le modificazioni idrogeologiche indotte dai fenomeni sismici sul regime naturale di alcune sorgenti. I dati acquisiti hanno permesso di individuare le principali risorse termo-minerali e di delineare un primo modello con-cettuale interpretativo dei meccanismi di mineralizzazione delle acque sotterranee. L'analisi integrata dei dati geologici e idrogeologici ha consentito, infine, di definire le principali caratteristiche di vul-nerabilità intrinseca degli acquiferi all'inquinamento e di identificare quei fattori che, localmente, possono accrescere il rischio di contaminazione della risorsa. L'insieme delle conoscenze e dei risultati acquisiti vengono esplicitati, oltre che mediante la presente memoria, anche attraverso una rappresentazione cartografica, in cui sono contenuti: a) la carta idrogeologica; b) la carta della vulne-rabilità all'inquinamento degli acquiferi; c) alcune ricostruzioni di scenari idrodinamici esemplificativi delle più impor-tanti risorse dell'Irpinia. I numerosi elementi idrogeologici, idrochimici e di vulnerabilità all'inquinamento ottenuti costituiscono un presupposto fondamentale per la salvaguardia quali-quantitativa delle acque sotterranee e l'ottimizzazione della gestione e uso delle risorse, in un territorio di rilevanza strategica per l'approvvigionamento idrico di diverse regioni dell'Italia meri-dionale. Parole chiave: Risorse idriche sotterranee, Potenzialità, Chimismo delle acque, Vulnerabilità all'inquinamento, Irpinia, Ita-lia meridionale. In this paper a synthesis of the current knowledge about the hydrogeology of the territory of Irpinia area has been depicted. The main aquifers (carbonate, alluvial and conglomeratic system aquifers) are examined in their most significant qualitative and quantitative characteristics, through the utilization of unpublished data recently collected. Moreover, they are graphically represented through a detailed hydrogeological map (1:100.000 scale), which highlights their schemes of groundwater flow. For each of the examined aquifers the degree of vulnerability to pollution is valued. Finally, the main hydrogeological aspects concerning the thermal-mineral waters are described. The collected evidence here displayed is an important tool for future applied research; in particular, it can help in improving the integrated management of the water resources of the southern Italian Regions.
... Equations (3) and (6) are that of Maillet [11], and the constant α is known as a recession coefficient, which controls the exponential decay of the discharge by the time. The recession coefficient depends on the geometric and hydraulic characteristics of the reservoir (Equations (4) and (8)); it is also the constant linking the discharge, Q(t), to the water volume stored V(t) in a linear reservoir: ...
The Poiseuille and Darcy laws describe the velocity of groundwater flow under laminar conditions. These laws were deducted empirically in conduit and porous systems, respectively, and are widely used to model the groundwater flow. The analytical relationship between these hydraulic laws has been found by draining a tank-reservoir. Based on equations found, the discharge in a conduit under the Poiseuille law can be transformed in the same amount flowing inside a darcian system, and vice versa. This transformation occurs, for example, in karst aquifers, from the matrix to karst conduits during discharge phases, and from conduits to matrix during recharge phases.
... For a century, it has been common practice to analyse recession and drying curves using a decreasing exponential model (Q=Q 0 e -αt ) (MAILLET, 1905). This model has the advantage of simplicity: the hydraulic behaviour of a watershed is characterised by a single number: the recession coefficient α. ...
Following the publication of Maillet’s model (1905), hydrologists became accustomed to using decreasing exponentials to model river flows after floods (recession). This law has the advantage of being very simple and it allows us to characterize drying-up using only two numbers: the flow at the beginning of the recession curve and the rate of decrease (expressed in % per day). Due to its simplicity, this model is commonly applied by hydrogeologists in karstic aquifers. However, this is not justified from a theoretical point of view (this type of exponential behaviour does not construe the emptying of a karstic aquifer). We will show that it is also not justified from the observations made on the largest spring in Europe: the Fontaine de Vaucluse (France). The drying curves there are better modelled by the succession of straight lines and hyperboles, accompanied by abrupt variations in flow. We then propose a hydraulic interpretation of this behaviour, which is due to the drainage of the karstic massif by a limited number of main channels in which the flow conditions vary with the water level and saturation of karst conduits. Recession curve details then represent a kind of X-ray of this network.
... As such, it can be effectively used to enhance local engineering construction and aid in developing appropriate karst groundwater resource utilization strategies in comparable environments (Chen et al., 2021). Boussinesq (1904) and Maillet (1905) were the first to describe discharge recession by an exponential function; over the years, this model has been widely used to study surface water and groundwater recession. Jadro Spring in Yugoslavia is a typical example where the recession stages and components of water quantity in aquifers are calculated (Karst Geology Study Group in China National Administration of Geology, 1978). ...
Herein, we conducted a study of the Zhangsanxi karst groundwater system in Zhangjiajie, Hunan Province, China, and used the results to develop a method for identifying the aquifer medium and its structural characteristics. To begin, rainfall, underground river flow dynamics, and groundwater level dynamics in the Zhangsanxi karst groundwater system were subjected to high-resolution monitoring to elucidate the groundwater system’s rainfall-hydrological response characteristics under varying rainfall amounts and intensities. Next, an exponential attenuation curve was employed to analyze how the law of attenuation applies to underground river discharge and groundwater level during a typical rainfall event. Finally, we determined the degree of karst development at different depths, so the data can serve as a reference for local decision makers regarding karst water disaster prevention and water resource utilization. The results show that the flow response lag time in the karst groundwater system depicts good correlation with the rainfall amount but is also affected by the rainfall intensity. Thus, under conditions of identical rainfall, increasing rainfall intensity corresponds to a progressively shorter underground river flow lag time. The area’s rainfall can be divided into four types, based on its concentration and intensity characteristics. The underground river flow generally has no evident response to type I rainfall, while the flow response lag time to types II III and IV rainfall is approximately 110, 60, and 40 h, respectively. Furthermore, the Zhangsanxi karst system’s water-bearing medium is dominated by karst fissures and pores, which account for about 2/3 of its open space. Large karst conduits and caves account for the remaining 1/3. The degree of karst development in this system depicts evident depth variation but, overall, tends to increase as a function of burial depth.
Responsible editor: Xianliang Yi.
... After calculation, the three springs in the study area have different average BFImax (Table 2). Meanwhile, the value of a calculation obtained by calculating [14] formula, and the value is 0.995; 0.996; and 0.995 for the Kalisirah, Jumbleng, and Kalikarak springs, 040006-3 respectively. After the diffuse flow is separated, the percentage of base flow is then calculated by dividing the diffuse flow by the total discharge. ...
Diffuse flow or slow-flow is the type of storage in karst aquifers that is the longest released during the recession period. For this reason, the length of time of release will affect the availability of reliable discharges in karst springs during the dry period. The higher the percentage of diffuse flow compared to the total discharge, the higher the discharge that can be relied upon to supply irrigation and domestic needs. This study is aimed to determine the spatial and temporal variations in diffuse flow percentages in the three largest springs on the north side of the Karangbolong karst (Kalisirah, Jumbleng, and Kalikarak springs). The primary data used is data from time-series water level recording with the HOBO U-30 logger, which then produces a discharge-hydrograph during the study period (November 2018-March 2020). Furthermore, baseflow separation is carried out automatically using the recursive digital filtering approach, where the BFImax value and recession constant are carried out manually by interpreting selected floods during the study period. The diffuse separation results show that, spatially, the monthly percentage of diffuse flow in the three springs is in the range of 80%, with the difference between the three springs not too large. The most volatile percentage was found in Kalisirah spring, with the smallest percentage (77.20%) occurring in November 2018 and the highest percentage in March 2020 (88.74%). Meanwhile, the percentage of diffuse flow experienced a drastic decrease in the incidence of flood peaks with varying ranges, namely at Kalisirah spring (9.06 - 31.16%); Jumbleng spring (14.30 - 60.73%); and Kalikarak spring (9.32 - 41.69%). As is the case with monthly percentages, the average percentage of diffuse flow during flood events in Kalisirah springs is the smallest (18.72%) when compared to Kalikarak springs (23.29%) and Jumbleng springs (43.34%). In short, the highest monthly diffuse flow fluctuations and the smallest percentage of diffuse flow during flood events indicate that aquifers that recharge Kalisirah springs have the most developed void sizes compared to the other two springs. Consequently, the spring with the lowest void development will have the most stable, reliable discharge for meeting both domestic and irrigation needs in this area. However, the differences between the three springs are not significant.
... L'analisi delle portate sorgentizie nel periodo di esaurimento, marginalmente influenzato dalle ricariche attive di precipitazione, ha permesso di determinare le curve di esaurimento ed i relativi coefficienti. Tali curve esprimono, quindi, le variazioni di portata dovute unicamente al deflusso dell'acquifero in assenza di ricariche (Civita, 1980) e sono state interpretate con equazioni di tipo esponenziale (Maillet, 1905): ...
1. INTRODUZIONE Scopo del presente lavoro è la caratterizzazione chimico-fisica delle acque di sette sorgenti spontanee, utilizzate a uso pota-bile dalla popolazione del Comune di Chiaravalle Centrale (CZ, Calabria, Italia), nell'ambito di un piano generale di censi-mento delle acque sorgentizie localizzate nello stesso territorio comunale. Il progetto nasce da una specifica convenzione stipulata in data 03/06/2007 tra il Comune di Chiaravalle Centrale e l'Istituto per i Sistemi Agricoli e Forestali del Mediter-raneo, Unità Operativa Staccata di Rende (CS), del Consiglio Nazionale delle Ricerche con il contributo del Laboratorio "Genesi degli inquinamenti nel Ciclo delle Acque" del Dipartimento Difesa Suolo dell'Università della Calabria. Con que-sta iniziativa, si è voluto valutare il grado di potabilizzazione delle acque sorgive e l'influenza della natura geo-litologica del substrato sulla loro qualità. Il progetto pilota si è articolato in due fasi distinte e successive. Nella prima fase sono state cen-site e catalogate le principali sorgenti nel territorio e sono state rilevate le caratteristiche geologiche e strutturali del bacino idrografico del Torrente Beltrame, nell'ambito del quale le sorgenti sono dislocate. Nella seconda fase sono stati rilevati e misurati i principali parametri chimico-fisici e idrologici delle sole sorgenti a regime perenne, abitualmente utilizzate dalla popolazione locale. L'analisi e l'interpretazione dei dati hanno permesso una piena caratterizzazione delle acque sorgive al fine di ricostruirne il modello di circolazione sotterranea. 2. MATERIALI E METODI Lo studio delle sorgenti, ubicate nella zona di alimentazione del bacino Beltrame, è stato condotto da settembre 2007 ad ago-sto 2008 in modo sistematico e puntuale, con lettura dei dati a cadenza settimanale. Fra le sedici sorgenti monitorate, sono state individuate sette sorgenti ritenute più rappresentative in termini di portata e attive in condizioni di regime perenne. La loca-lizzazione delle sorgenti attive è riportata nell'ortofoto del bacino idrografico del torrente Beltrame (Fig. 1) e nella carta geo-logica dove sono schematizzate le sezioni rappresentative dei rapporti geometrici tra i diversi tipi litologici affioranti (Fig. 2). Il lavoro si propone di analizzare le caratteristiche idrogeologiche e geochimiche di alcune sorgenti, site nel bacino i-drografico del torrente Beltrame nel territorio comunale di Chiaravalle Centrale (CZ, Italia). Il monitoraggio delle sor-genti attive, svolto dall'Istituto per i Sistemi Agricoli e Forestali del Mediterraneo (I.S.A.FO.M) del Consiglio Nazionale delle Ricerche (C.N.R.)-Sezione di Rende (CS, Italia) nel biennio 2008-2009, ha consentito di rilevare e misurare i principali parametri chimico-fisici e idrologici di tali emergenze per valutare il loro grado di potabilità e le relative ca-ratteristiche idrodinamiche. Le analisi dei dati raccolti hanno evidenziato buone condizioni di potabilità ed hanno per-messo di distinguere due gruppi di sorgenti caratterizzati da differenti velocità di deflusso e da ritardi di piena, rispet-to ai valori di precipitazione, variabili tra uno e due mesi. Parole chiave: Sorgenti, Coefficiente di esaurimento, Deflusso sotterraneo, Chiaravalle Centrale (Calabria, Italia). The study aims to investigate the hydrological and geochemical characteristics of some spring waters, located in the basin of Beltrame river in the municipal area of Chiaravalle Centrale (Catanzaro, Italy), used for local hydropotable purposes. The survey of the active sources, undertaken by National Research Council, Institute for Agricultural and Forest Systems in the Mediterranean, Rende Research Unit (Cosenza, Italy) in a two year period 2008-2009, has enabled to estimate the physical, chemical and hydrological features of these spring waters to evaluate their standards of drinkableness and their hydrokinetics. The analyses have suggested that waters are potable and have enabled to discriminate two spring water groups with different exhausting velocities and with different time lags variable from one to two months compared with rainfall data.
Susuz karst aquifer is a mountainous and highly karstified aquifer located at the Central Taurus karst belt, Seydişehir, Türkiye. Pınarbaşı karst spring is a major water resource of the Susuz karst aquifer which drains approximately 15 million m3 of water annually, mostly between January and July. As the Pınarbaşı spring dries up for the rest of the year, local water needs frequently emerge during the dry periods, especially for animal livestock and domestic usage. However, one major problem in the karst region is the decreasing trend in the spring discharge rate and increasing length of the dry period mainly due to the impact of climate change. For this reason, to reduce the climate impact on the karst aquifer it is essential to explore alternative engineering solutions where they are applicable. This study proposes the construction of a cave dam in the Susuz karst system to retain and store groundwater during the dry period. Based on the accumulated hydrogeological knowledge and experiences in the karst region, we first conceptualized the cave dam construction and then indicated the positive influence of the stored groundwater under changing climate considering two main climate scenarios (SSP245 and SSP585). Our findings indicate that the (proposed) cave dam potentially stores 4 million m3 of water, which equals nearly 35 % of the mean annual spring discharge under current climate conditions while this amount is also expected to rise over 50 % of the total discharge in future climate conditions.
Water has been studied by many trades throughout history, from engineering to medicine. In fact, one of the most famous stories in medicine centers around a water pump. Nearly 200 years ago, a cholera outbreak in a London suburb was caused by wastewater contaminating the groundwater that supplied this pump. At this time, physicians were generally ignorant regarding the potential for diseases to spread via water. The education of physicians at that time and place taught that diseases spread from sources of decaying organic matter through air (miasmatic theory). John Snow, a physician with a broad range of expertise, including mathematics and chemistry, investigated this outbreak with a broader perspective than his peers. He identified the contaminated water source as the cause of the outbreak and, thereby, falsified the (now-defunct) miasmatic theory and helped establish a new specialization: epidemiology. Although this story is commonly told from a medical perspective, it could have easily been a story about water. It could be argued that John Snow, like many scientists before the twentieth century, was more of a generalist than a medical specialist. His research on cholera represents a benchmark study in water science: the discovery of how social and hydrological processes can interact to influence contaminant fate and transport (such an aim would certainly be considered ahead of its time by hydrologists, as it fits squarely within the now-fashionable “socio-hydrology” paradigm). One reason this story is not more commonly associated with the field of hydrology may be because water science as a specialization, the formal discipline of hydrology as we understand it today, did not yet exist.
Considering the importance of fractured rock aquifers in the hydrogeologic process, this research aimed to analyze the flow regime, internal degree of karstification, and estimate storage volume in fractured rock aquifers of the Germi Chai Basin in northwest Iran, which is attributed to its active tectonics, erosion, and the lithological diversity. Given the geological setting, the hypothesis is that this basin is characterized by a high degree of karstification and diffuse or intermediate flow regime leading to variation in discharge flow rate. The hydrodynamic and hadrochemical analysis was conducted on 9 well-distributed springs across the basin from 2019 to 2020. The maximum flow rate in most of the springs appeared in the early wet season despite their different levels of fluctuations on the monthly discharge time series. Analyzing the spring recession curve form revealed an aquifer containing multiple micro-regimes with α recession coefficients and a degree of karstification ranging between 0.001 to 0.06 and 0.55 to 2.61, respectively. These findings indicated a dominant diffuse and intermediate flow system resulting from the development of a high density of fractures in this area. The electrical conductivity of the spring changes inversely proportional to the change in flow discharge, indicating the reasonable hydrological response of the aquifer to rainfall events. Hydrograph analysis revealed that the delay time of spring discharge after rainfall events mostly varies between 10 to 30 days. The total dynamic storage volume of the spring for a given period (2019–2020) was estimated to be approximately 1324 million cubic meters reflecting the long-term drainage potential and high perdurability of dynamic storage. Estimating the maximum and minimum ratio revealed that the springs recharging system in Germi Chai Basin comes under the slow aquifers category. This finding provides valuable insight into the hydrogeological properties of fractured rock aquifers contributing to effective water management strategy.
RESUMEN La relación de Adolfo Eraso con la Cueva de los Chorros comenzó, posiblemente, a finales de los 60 del siglo pasado, cuando intervino como asesor de Ullastre y Masriera en el artículo que poblicaron en 1968. A principios de los 90 trabajó en la toma de datos, tanto en la cueva de los Chorros como en el Calar del Mundo, para la aplicación de su método sobre la predicción de direcciones de drenaje que utilizó en muchas otras zonas emblemáticas de la Península Ibérica; aunque, los resultados de estos trabajos no fueron publicados hasta 2001. También a comienzos de los 90, publicó un artículo corto de tipo divulgativo sobre el famoso fenómeno de El Reventón. Las investigaciones de tipo espeleológico y científico en la Cueva de los Chorros han transcurrido sin interrupción durante las últimas 7 décadas. El desarrollo de galerías descubiertas no ha parado de crecer, con más de 30 km topografiados hasta la fecha y varios frentes de exploración en nuevas zonas recién descubiertas. En este artículo se describen: 1) los avances realizados tanto desde el punto de vista espeleológico como científico; 2) el entorno geológico y geomorfológico en el que se ha generado la cueva; 3) los primeros resultados obtenidos tras la colocación de sensores en nodos estratégicos de la cavidad para monitorizar las extraordinarias crecidas de caudal que se producen cada cierto tiempo, su comparación con los datos de la estación de aforo del río Mundo de la red SAIH y con la estación climática instalada en el polje de la Cañada de los Mojones; 4) información preliminar sobre los parámetros hidráulicos del acuífero y el grado de karstificación existente que puede deducirse de estos datos; 5) la forma en la que el agua penetra en la cueva tras las crecidas, el volumen infiltrado durante los eventos lluviosos y la velocidad de circulación del agua por el acuífero y 6) la organización de las redes kársticas y sus causas y la evolución espeleogenética de la cueva desde que la superficie del Calar quedó emergida al final del Mioceno, que puede deducirse de la información existente. A pesar de todo lo anterior, el trabajo por hacer aún es enorme, si bien, por primera vez se dispone de datos precisos que permiten estudiar la relación entre la cavidad y el acuífero desde el punto de vista hidráulico. La cueva constituye, posiblemente, el mejor ejemplo de looping cave de España y actualmente puede considerarse un «laboratorio» natural para el estudio de este tipo de cavidades.
Karst aquifers are important sources of fresh water on a global scale. The hydrological modelling of karst spring discharge, however, still poses a challenge. In this study we apply a transfer function noise (TFN) model in combination with a bucket-type recharge model to simulate karst spring discharge. The application of the noise model for the residual series has the advantage that it is more consistent with assumptions for optimization such as homoscedasticity and independence. In an earlier hydrological modeling study, named Karst Modeling Challenge (KMC; Jeannin et al., J Hydrol 600:126–508, 2021), several modelling approaches were compared for the Milandre Karst System in Switzerland. This serves as a benchmark and we apply the TFN model to KMC data, subsequently comparing the results to other models. Using different data-model-combinations, the most promising data-model-combination is identified in a three-step least-squares calibration. To quantify uncertainty, the Bayesian approach of Markov-chain Monte Carlo (MCMC) sampling is subsequently used with uniform priors for the previously identified best data-model combination. The MCMC maximum likelihood solution is used to simulate spring discharge for a previously unseen testing period, indicating a superior performance compared to all other models in the KMC. It is found that the model gives a physically feasible representation of the system, which is supported by field measurements. While the TFN model simulated rising limbs and flood recession especially well, medium and baseflow conditions were not represented as accurately. The TFN approach poses a well-performing data-driven alternative to other approaches that should be considered in future studies.
Karst springs and aquifers are significant resources globally yet continue to be poorly understood because of their heterogeneity in porosity and response to climate variability. In semiarid, mountainous regions where total precipitation and groundwater recharge rates will likely decline due to climate change, improved understanding of karst groundwater recharge processes is imperative to plan for future hydrologic responses. The Colorado Plateau is a high‐elevation, heavily dissected region of over 2,000 m thickness of sedimentary rock units containing multiple layered karst aquifers. This is the first study to use hydrograph analyses on springs in the uppermost regional Coconino aquifer (C aquifer) of the southern Colorado Plateau in Arizona to detail karst aquifer response to recharge. Coupled hydrograph and stable isotope (δ 18 O and δ 2 H) analyses document seasonal recharge as well as groundwater mixing and storage processes in the C aquifer. A critical relationship between seasonal snowpack timing and duration of ephemeral spring discharge indicates seasonal buffering and attenuation to drought. Event‐scale hydrograph analyses show rapid hydrologic responses to precipitation in two ephemeral karst spring systems and quick drainage without extended seasonal snowmelt contribution. As climate change intensifies throughout the southwestern United States, and other drought‐ridden areas of the world, aquifer and spring ecosystem conditions will significantly worsen without mitigation measures. The recharge and groundwater flow processes demonstrated in this study of a complex karst system support informed water resource decision making on the southern Colorado Plateau and other climate‐sensitive regions around the world.
Analysis of karst spring recession hydrographs is essential for determining hydraulic parameters, geometric characteristics, and transfer mechanisms that describe the dynamic nature of karst aquifer systems. The extraction and separation of different fast- and slow-flow components constituting a karst spring recession hydrograph typically involve manual and subjective procedures. This subjectivity introduces a bias that exists, while manual procedures can introduce errors into the derived parameters representing the system. To provide an alternative recession extraction procedure that is automated, fully objective, and easy to apply, we modified traditional streamflow extraction methods to identify components relevant for karst spring recession analysis. Mangin's karst-specific recession analysis model was fitted to individual extracted recession segments to determine matrix and conduit recession parameters. We introduced different parameter optimization approaches into Mangin's model to increase the degree of freedom, thereby allowing for more parameter interaction. The modified recession extraction and parameter optimization approaches were tested on three karst springs under different climate conditions. Our results showed that the modified extraction methods are capable of distinguishing different recession components and derived parameters that reasonably represent the analyzed karst systems. We recorded an average Kling–Gupta efficiency KGE > 0.85 among all recession events simulated by the recession parameters derived from all combinations of recession extraction methods and parameter optimization approaches. While there are variabilities among parameters estimated by different combinations of extraction methods, optimization approaches, and seasons, we found much higher variability among individual recession events. We provided suggestions to reduce the uncertainty among individual recession events and raised questions about how to improve confidence in the system's attributes derived from recession parameters.
The behaviour of river flows during periods of recession can be better identified than in other periods. The Master Recession Curve (MRC) approach is a technical approach that is quite effective and efficient in modelling baseflow. This study aims to compare the shape of the MRC between linear and exponential reservoir models. The research method uses two linear reservoir models, the Depuit-Boussinesq equation and an exponential model based on exponential hydraulic conductivity. The results showed that the combination of recession parameters (initial recession discharge, constant and coefficients) for MRC manually linear and exponential reservoir models, and hybridization of genetic algorithm processes, showed that MRC visualization for linear reservoir models was more optimal compared to exponential reservoir models. These results are closely related to the slope of the MRC, where the linear reservoir model is gentler, and the exponential reservoir model is relatively steeper. The slope of the MRC for both reservoir models relates to the storage capabilities of the baseflow and the hydraulic conductivity properties of the study area. The gentle slope of the MRC has the properties of relatively slow storage and is relatively long stored. In contrast, the steep slope of the MRC determines the somewhat wasteful nature of storage.
The role of aquifers in the seasonal and multiyear dynamics of streamflow is undisputed: in many temperate catchments, aquifers store water during the wet periods and release it all year long, making a major contribution to low flows. The complexity of groundwater modelling has long prevented surface hydrological modellers from including groundwater level data, especially in lumped conceptual rainfall–runoff models. In this article, we investigate whether using groundwater level data in the daily GR6J model, through a composite calibration framework, can improve the performance of streamflow simulation. We tested the new calibration process on 107 French catchments. Our results show that these additional data are superfluous if we look only at model performance for streamflow simulation. However, parameter stability is improved, and the model shows a surprising ability to simulate groundwater levels with a satisfying level of performance in a wide variety of hydrogeological and hydroclimatic contexts. Finally, we make several recommendations regarding the model calibration process to be used according to the hydrogeological context of the modelled catchment.
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