Figure 6 - uploaded by Desiree Tullos
Content may be subject to copyright.
Per cent of Conservation Pool achieved by refill date. Refill was evaluated as a percentage of water stored on the individual reservoir's refill target dates to maximum Conservation Pool storage. Error bars represent the 95th and 5th percentile values. Results are presented for the A1B GHG emission scenario only.
Source publication
This study investigated how reservoir performance varied across different hydrogeologic settings and under plausible future climate scenarios. Modeling was conducted for the Santiam River basin, OR, USA, comparing the North Santiam Basin (NSB), with high permeability and extensive groundwater storage, and the South Santiam Basin (SSB), with low per...
Contexts in source publication
Context 1
... both the simulated historical and future inflows, the reservoirs did not reliably refill to maximum Conservation Pool ( Figure 6) by their respective deadlines in May ( Figure 3). A warmer climate did not appear to affect reservoir refill, particularly when uncertainty was considered. ...
Context 2
... projected increases in winter flow and decreases in summer low flows, the ability to meet summer environmental flow targets in one of the two study basins was the only per- formance measure conclusively impacted by the simulated future climate. Contrasting the results of other studies on cli- mate change impacts on reservoir refill ( Payne et al. 2004) the changes in hydrology did not appear to appreciably affect the ability of the reservoirs to refill (Figure 6), or the ability to meet spring environmental flow targets (Figure 8). While results indicated that hydropower production could decrease in the future (Figure 10), consistent with other studies (Schaefli et al. 2007, Vonk et al. 2014), the changes were rarely larger than uncertainties. ...
Context 3
... results provided limited evidence of a response in reservoir operations performance to a changing climate. Despite projected increases in winter flow and decreases in summer low flows, the ability to meet summer environmental flow targets in one of the two study basins was the only per- formance measure conclusively impacted by the simulated future climate. Contrasting the results of other studies on cli- mate change impacts on reservoir refill ( Payne et al. 2004) the changes in hydrology did not appear to appreciably affect the ability of the reservoirs to refill (Figure 6), or the ability to meet spring environmental flow targets (Figure 8). While results indicated that hydropower production could decrease in the future (Figure 10), consistent with other studies (Schaefli et al. 2007, Vonk et al. 2014), the changes were rarely larger than uncertainties. Thus, reduction in the reliability of meet- ing summer flow targets (Figure 9) provided the only evi- dence of being sensitive to climate change, and that larger hydrologic changes than those projected for the A1B GHG emission scenario were required for the other operating objectives to be detectably impacted. Thus, while some studies have suggested the need to modify reservoir oper- ations to mitigate the effects of climate changes ( Watts et al. 2011) or to reduce the impact of climate change on water resources ( Watts et al. 2011, Vonk et al. 2014), model simulations indicate that reservoir operations can generally accommodate hydrologic changes in the SRB, but also high- light that the important operating objective of summer flow targets may be ...
Context 4
... both the simulated historical and future inflows, the reservoirs did not reliably refill to maximum Conservation Pool ( Figure 6) by their respective deadlines in May ( Figure 3). A warmer climate did not appear to affect reservoir refill, particularly when uncertainty was considered. For both historical and future scenarios, while the reservoirs failed to reliably refill by their May deadlines, they often reached water levels very close to maximum Conservation Pool (Figure 7) and refilled within 15 days of the refill deadline in 90% of the years, based on median runoff scenarios. Rela- tive to historical observations, the future appeared to have an initially higher but declining refill reliability, though the differences were all within the range of uncertainty. Thus, despite not refilling by the deadline each year, the ability of reservoirs to eventually refill, both in the past and future, was high and does not appear to be appreciably impacted by a changing ...
Similar publications
This study assessed impacts of climate change on the frequency and severity of floods in the Pasig-Marikina River basin. Researchers used the historical data from PAG-ASA (Philippine Atmospheric, Geophysical and Astronomical Services Administration), specifically from Science Garden weather station. The historical data are coupled with a global cli...
Citations
... (Brekke et al., 2009;Quan & Kittiwet, 2020;Sheer et al., 2014) presented a flexible methodology for conducting climate change risk assessments involving reservoir operations. (Ahmadi et al., 2015;Mateus & Tullos, 2017;Raje & Mu-jumdar, 2010) have investigated the potential impacts of future climate change on stream flow and reservoir operation performance in a Northern American Prairie watershed. However, in Ethiopia, few studies including (Getachew et al., 2021;Ibrahim Mohammed, 2020;Rientjes et al., 2011), have addressed water management and adaptation measures in the face of changing water balance due to climate change with the implication that much more is still required to be done ahead. ...
... It is also essential to examine economically optimal operation. The inflows to the dams are uncertain (Mateus & Tullos, 2017) and vulnerable to long-term operation goals. So, curtailing operation rules need to be revived for future inflow conditions (Jang et al., 2017). ...
The present investigations focus on developing an appropriate model for streamflow generation of a partially gauged basin and the operation of small storage in a tropical, seasonal river basin. The small storages created through the vented dams effectively conserve and sustain the water resources for the lean season. Hence, it is pertinent to develop streamflow models to derive streamflow series at the vented dam locations. In the present investigation, streamflow modeling was attempted using response surface and neural network models in a first of its kind. Out of them, the Response Surface Box Behnken model was found to be most efficient in generating streamflow, with Nash Sutcliff’s efficiency above 0.617. Further, it is also essential to operate these small storages to maintain a sustainable, ecological flow in the river course.
The operation policy for seasonal storage like vented dams is yet to be reported in the literature. The present work uses reservoir simulation and multi-objective optimization to derive such storages operation policy storage through hedging operations, with modified shortage index and mean event deficit as objectives. The performance indicators evaluated the operation policy for eight vented dams of the basin. The results illustrate that vented dams indicate shortages while satisfying the respective demands. The results demonstrate that hedging improves the reservoir's performance by reducing the mean event deficit of 0.268 to 0.044 Mm³ before and after hedging. The frequency and intensity of shortages were also reduced through hedging for the tropical, seasonal river basins.
... They showed that the hedging policy can effectively reduce the impacts of water deficit caused by climate change conditions. Furthermore, Mateus and Tullos (2017) evaluated the sensitivity, reliability, and vulnerability of reservoirs in the Santiam River basin in Oregon, USA, under climate change conditions. The results of their study indicated a reduction in the reliability of a summer stream entering the reservoir under the effects of climate change. ...
Reservoirs play a fundamental role in enhancing sustainable development and economic circumstances, especially in areas with limited water resources. Recently , experts in water resources management have been faced with global warming and climate change as two critical issues that are causing serious problems in water resources. Accordingly, the current study attempts to evaluate the future climate change impacts on agricultural reservoir operation. The results indicated an increase in mean long-term temperature, decreased reservoir's inflow, and an increase in the agricultural water requirement for the Jarreh reservoir system in southwestern Iran, during the period of 2025-2054, under the RCP 8.5 scenario. The results also showed a decrease in reliability (37%) and an increase in vulnerability (9%) using standard operation policy (SOP) under future climate conditions. Due to the predicted drought conditions for the study area, a two-dimensional hedging policy is proposed to mitigate the negative effects of climate change. The results of the hedging model indicated an improvement in the performance of indices in comparison with the use of SOP under climate change impacts. Generally, by using the hedging policy, decreased vulnerability (24%) and reduced maximum deficiencies (14%) are expected for future climate changes.
... The three indicators can reflect the different aspect of the recovery capacity and complement each other (Asefa et al. 2014). They were widely used to quantitatively assess the performance of reservoirs (McMahon et al. 2006;Mateus and Tullos 2017), water supply systems (Fowler et al. 2003;Liu et al. 2012a, b;Liu 2019). At present, two methodologies are used for estimating RRV. ...
Water resources allocation is facing great challenge, since hydrological series have shown non-stationarity with high uncertainty due to climate change and human activities. Adaptive measures are suggested to respond to the challenge. Aiming at quantitatively assess the impact of adaptive measures on optimal water resources allocation, we proposed a framework based on reliability, resilience and vulnerability indicators. Two representative concentration pathway (RCP) scenarios (RCP2.6 and RCP4.5) of one global climate model were used to project future climate, and the variable infiltration capacity hydrological model was used to simulate streamflow. Three adaptive measures [water saving measure, water transfer project, dynamic control of flood limiting water levels (FLWLs) for reservoir operation] were combined to eight scenarios, then scenarios were applied to the allocation model to get different optimal allocation schemes which were assessed by RRV indicators. The results show that water saving measure decreases the vulnerability by 79 × 106 m3, water transfer project decreases the resilience by 17% in every scenario and dynamic control of FLWLs increases the reliability by 23.53% to the greatest scale. But the impacts of latter two adaptive measures are restricted to the areas which are geographically close to water supply projects. The uneven spatial distribution and decrease of streamflow will increase the risk of water shortage in the future. Optimal water allocation can reduce this risk and make 23 of 28 operational zones stable. Water saving measure is significantly valid in the rest 5 operational zones, but its impact is not positive to all water use sectors. Overall, our study helps understanding the interaction between adaptive measures and water resources system, and making guidelines for effective adaptation planning.
... To better understand the performance of the reservoir and its operating rules under climate change, the indicators described above were considered to determine the supply reliability, vulnerability of water needs, and the system's resilience for each simulated scenario. This approach has been applied in several reservoir studies, including the Sorraia basin where the Montargil reservoir is included [52][53][54]. As a failure reference, the volume of ~10 hm 3 was considered in case of extreme necessity when half of the dead volume could be used. ...
... This shows that in the future, the stored volume is expected to be below the dead volume for several months, something that has never happened in the past ( Figure 15). This is mainly due to the impact of runoff decrease in the reservoir, which is consistent with the literature as shown by Mateus et al. [54] when studying the reliability of six reservoirs in Scotland or Afzal et al. [55] when analyzing the vulnerability of the Pong reservoir, India. Future water demand scenarios considered in both studies showed a reliability reduction and a vulnerability increase of the simulated reservoirs, advancing then with future water management strategies to cope with those predictions. ...
This paper describes an integrated modelling approach to study water use vulnerability in a typical Mediterranean basin under different climate change projections. The soil water assessment tool (SWAT) and the MOHID (from modelo hidrodinâmico) Water model were used to evaluate the impacts of two climate scenarios (GFDL-ESM2M and IPSL-CM5A-LR) on water availability in Montargil’s basin and reservoir (Portugal) during two decadal timelines (2030 and 2060). Reservoir performance metrics were estimated considering also two water demand scenarios: an average of the water demand in the last 10 years; and the largest annual demand of the last 10 years. The SWAT model results showed a future decrease of inflows to the reservoir, with its volumetric reliability decreasing from 100% in the historical simulation to about 60–70% in the IPSL-CM5A-LR climate scenario and 40–50% in the GFDL-ESM2M climate scenario. The time reliability also decreased to less than 30%, while the resiliency for the water demand decreased to an average 20–35% for both climate scenarios. These impacts indicate the importance of the managing systems in an integrative mode to prevent water resources reduction in the region.
... Therefore uncertainties related to the input data "operational rules" 2) are more difficult to analyse as they depend on human decision making which is not always "ruled". (Mateus and Tullos, 2016) estimated changes in streamflow and reservoir reliability under climate variability in two basins with different hydro-geological settings in North-western United States. They assessed climate related 15 sensitivity and uncertainties in HEC-ResSim modelling performance by comparing model results with inputs from VIC hydrological modelling simulations forced with eight climate model projections. ...
... Uncertainties related to HEC-ResSim modelling algorithms deal with channel routing and reservoir storage without taking into consideration spatially distributed environmental processes. It can be assumed that uncertainties are more related to input data and the extreme tropical hydro-morphological dynamics (Mateus and Tullos, 2016). 30 For the J2000 model, however, the knowledge on uncertainties related to model structure and especially parameter sensitivity would help to define an uncertainty range for the use of the model framework for predictions and decision support. ...
Hydrological droughts are one of the most damaging disasters in terms of economic loss in Central Vietnam and other regions of South East Asia severely affecting agricultural production and drinking water supply. Their increasing frequency and severity can be attributed to extended dry spells and increasing water abstractions for e.g. irrigation and hydropower development to meet the demand of dynamic socioeconomic development. Based on hydro-climatic data for the period from 1980 to 2013 and reservoir operation data, the impacts of recent hydropower development and other alterations of the hydrological network on downstream streamflow and drought risk were assessed for a mesoscale basin of steep topography in Central Vietnam, the Vu Gia Thu Bon (VGTB) river basin. The Just Another Modelling System (JAMS)/J2000 was calibrated for the VGTB river basin to simulate reservoir inflow and the naturalized discharge time series for the downstream gauging stations. The HEC-ResSim reservoir operation model simulated reservoir outflow from eight major hydropower stations as well as the reconstructed streamflow for the main river branches Vu Gia and Thu Bon. Drought duration, severity and frequency was analysed for different time scales for the naturalized and reconstructed streamflow by applying the daily varying threshold method.
Efficiency statistics for both models show good results. A strong impact of reservoir operation on downstream discharge at the daily, monthly, seasonal and annual scale was detected for four discharge stations relevant for downstream water allocation. In accordance with the reports from local stakeholders, we found a stronger hydrological drought risk for the anthropogenically impacted reconstructed streamflow. We conclude that the calibrated model setup provides a valuable tool to quantify the different origins of drought to support cross-sectorial water management and planning in a suitable way to be transferred to similar river basins.
Climate change is altering flood risk globally, with local variations prompting the necessity for regional assessments to guide the planning and management of water-related infrastructures. This study details an integrated framework for assessing future changes in flood frequencies, using the case of Bitlis Creek (Turkey). The precipitation and temperature simulations of 21 global circulation models (GCMs) from the coupled model intercomparison project phase 6 (CMIP6) are used to drive the developed soil and water assessment tool (SWAT) model in generating daily streamflow projections under the CMIP6 historical experiment and the shared socio-economic pathway (SSP) scenarios of SSP245 and SSP585. Five probability distribution functions are considered to calculate the 5-, 10-, 25-, 50-, 100-, and 500-year flood discharges for the historical period 1955–2010 and the future periods 2025–2074 and 2025–2099. The quantification of climate change impacts on the design discharges is based on the medians of the flood discharges obtained for the climate data of each GCM, using the best-fitted distribution functions according to the Kolmogorov–Smirnov test results. The findings illustrate significant increases in discharge rates, ranging from 21.1 to 31.7% for the 2025–2099 period under the SSP585 scenario, highlighting the necessity of considering changing climate conditions in designing water-related infrastructures.
Reduction of uncertainty in climate change projections is a major challenge in impact assessment and adaptation planning. General circulation models (GCMs) along with projection scenarios are the major sources of uncertainty in climate change projections. Therefore, the selection of appropriate GCMs for a region can significantly reduce uncertainty in climate projections. In this study, 20 GCMs were statistically evaluated in replicating the spatial pattern of monsoon propagation towards Peninsular Malaysia at annual and seasonal time frames against the 20th Century Reanalysis dataset. The performance evaluation metrics of the GCMs for different time frames were compromised using a state-of-art multi-criteria decision-making approach, compromise programming, for the selection of GCMs. Finally, the selected GCMs were interpolated to 0.25° × 0.25° spatial resolution and bias-corrected using the Asian Precipitation – Highly-Resolved Observational Integration Towards Evaluation (APHRODITE) rainfall as reference data. The results revealed the better performance of BCC-CSM1-1 and HadGEM2-ES in replicating the historical rainfall in Peninsular Malaysia. The bias-corrected projections of selected GCMs revealed a large variation of the mean, standard deviation and 95% percentile of daily rainfall in the study area for two futures, 2020–2059 and 2060–2099 compared to base climate.
