Laura Lautz

National Science Foundation | NSF · Earth sciences

Regulatory agencies routinely assess the presence of stray gas release from unconventional gas wells by sampling for methane in nearby groundwater after the well is drilled or if citizens complain about methane in their water. We studied whether methane concentrations in groundwater naturally vary through time in a shale gas basin where unconventio...

Urbanization negatively impacts water quality in streams by reducing stream‐groundwater interactions, which can reduce a stream's capacity to naturally attenuate nitrate. Meadowbrook Creek, a first order urban stream in Syracuse, New York, has an inverse urbanization gradient, with heavily urbanized headwaters that are disconnected from the floodpl...

Natural beaver ponds help connect the stream to the floodplain, maintain late summer low flows, and reduce peak flow during high flow events by offering temporary surface water storage. When beavers are extirpated from the landscape, stream degradation often ensues. This study assesses the impact of beaver dam analogues (BDA) as a stream restoratio...

River systems in the mountain western USA have been shaped by the presence of beavers for millennia. However, beavers have been extirpated from the landscape in many places, leading to excessive stream incision and streambank erosion. One common strategy to mitigate this issue is to deploy beaver dam analogue (BDAs) as a stream restoration techniqu...

Beaver dam analogues (BDAs) are a stream restoration technique that is rapidly gaining popularity in the western United States. These low‐cost, stream‐spanning structures, designed after natural beaver dams, are being installed to confer the ecologic, hydrologic, and geomorphic benefits of beaver dams in streams that are often too degraded to provi...

Sodium chloride has long been used for winter deicing, although its legacy use has resulted in rising chloride concentrations in urban watersheds. Persistently high chloride levels impair drinking water resources and threaten the health of aquatic life and vegetation. In urban areas, chloride fate and transport is impacted by human modification of...

Residential development and urbanization have increased nutrient loads to streams and groundwater through increased use of fertilizers and discharge of wastewater effluent. Stream degradation in urbanizing areas has simultaneously reduced natural attenuation of nutrients. In this context, cemeteries are an often-overlooked land use that may contrib...

Beaver dam analogues (BDAs) are a cost‐effective stream restoration approach that leverages the recognized environmental benefits of natural beaver dams on channel stability and local hydrology. Although natural beaver dams are known to exert considerable influence on the hydrologic conditions of a stream system by mediating geomorphic processes, n...

Hyporheic zones (HZs) influence biogeochemistry at the local reach scale with potential implication for water quality at the large catchment scale. The characteristics of the HZs (e.g., area, flux rates, and residence times) change in response to channel and aquifer physical properties, as well as to transient perturbations in the stream–aquifer sy...

The Piper Diagram has increased in popularity since its 1944 introduction and is now one of the most familiar and effective tools in the hydrogeologist's toolbox. Within the Piper Diagram, three points on three related plots fully display the major ionic species of a water sample. Recently the size and availability of datasets have increased as add...

The dramatic loss of glacial mass in low latitudes is causing shifts in downstream water availability and use during the driest months of the year. The world’s largest concentration of tropical glaciers lies in the Cordillera Blanca range of Peru, where glacial runoff is declining and regional stresses are emerging over water resources. Throughout...

Stream temperature is a measure of water quality that reflects the balance of atmospheric heat exchange at the air-water interface and gains or losses of water along a stream reach. In urban areas, stormwater sewers deliver water with varying magnitude and temperature to streams at variable timescales. Understanding the impacts of stormwater throug...

To better understand the effects of climate change on streamflow, the hydrologic response to both temperature and precipitation needs to be examined at the mesoscale. New York State provides a hydrologically diverse mesoscale region, where sub-regional clusters of watersheds may respond differently to changes in temperature and in seasonal precipit...

Surface soil moisture is a critical but often neglected component of the hydrologic budget. Within mountain environments, surface soil moisture is highly heterogeneous and challenging to measure. Point measurements are often poorly representative of larger areas, while satellite pixels are generally too coarse in these topographically varied landsc...

In recent years, thermal infrared (TIR) cameras have improved in resolution and accuracy while their cost has declined. By deploying a ground-based TIR camera to collect time-lapse images, it is now possible to acquire high-resolution stream temperatures through both space and time. However, while ground-based TIR is useful for qualitatively identi...

While stream temperature energy balance models are useful to predict temperature through time and space, a major unresolved question is whether fluctuations in stream discharge reduce model accuracy when not exactly represented. However, high frequency (e.g. sub‐daily) discharge observations are often unavailable for such simulations, and therefore...

The rapidly melting glaciers of Peru are posing new risks to regional dry season water supplies, and this is evident in the Cordillera Blanca, the mountain range with the world's largest concentration of tropical glaciers. Permanent ice loss is causing reductions to dry season streamflow, which is coupled with shifting demands and control over wate...

Streams strongly influenced by groundwater discharge may serve as "climate refugia" for sensitive species in regions of increasingly marginal thermal conditions. The main goal of this study is to develop paired air and stream water annual temperature signal analysis techniques to elucidate the relative groundwater contribution to stream water and t...

The long-term application of road salts has led to a rise in surface water chloride (Cl⁻) concentrations. While models have been used to assess the potential future impacts of continued de-icing practices, prior approaches have not incorporated changes in climate that are projected to impact hydrogeology in the 21st century. We use an INtegrated CA...

Concern over contamination of groundwater resources in areas impacted by anthropogenic activities has led to an increasing number of baseline groundwater quality surveys intended to provide context for interpreting water quality data. Flexible screening tools that can parse through these large, regional datasets to identify spatial or temporal chan...

Numerous closed-basin prairie wetlands throughout the Prairie Pothole Region (PPR) of North America maintain moderate surface pond salinities (total dissolved solids [TDS] from 1 to 10gL⁻¹) under semiarid climate by accumulation of gypsum and saline lenses of sulfate-rich porewater (TDS>10gL⁻¹) in wetland sediments during droughts. In order to unde...

Accelerating glacier recession in tropical highlands and in the Peruvian Andes specifically is a manifestation of global climate change that is influencing the hydrologic cycle and impacting water resources across a range of socio-environmental systems. Despite predictions regarding the negative effects of long-term glacier decline on water availab...

Process-based models of fluid flow and heat transport in fluvial systems can be used to quantify unknown spatial and temporal patterns of hydrologic fluxes and to predict system response to change. In this study, a deterministic stream heat budget model, the HFLUX Stream Temperature Solver (HFLUX), is developed and evaluated using field studies. Fi...

Nitrate (NO3⁻) dynamics in urban streams differ from many natural streams due to stormwater runoff, sewage inputs, decreased groundwater discharge, often limited hyporheic exchange, increased primary productivity, and limited carbon input. We investigated NO3⁻ dynamics in a first-order urban stream in Syracuse, NY, which has urbanized headwaters an...

Iodine is a biophilic halogen that is concentrated in organic rich rocks and soils, but very little is known about its export from forested headwater catchments. The purpose of our study is to assess the dynamics of terrestrial iodine fluxes by evaluating contributions of pathways of iodine under a variety of flow conditions, and to assess the spat...

Analytical solutions that use diurnal temperature signals to estimate vertical fluxes between groundwater and surface water based on either amplitude ratios (Ar) or phase shifts (Δϕ) produce results that rarely agree. Analytical solutions that simultaneously utilize Ar and Δϕ within a single solution have more recently been derived, decreasing unce...

Heat is a powerful tracer to quantify fluid exchange between surface water and groundwater. Temperature time series can be used to estimate pore water fluid flux, and techniques can be employed to extend these estimates to produce detailed plan-view flux maps. Key advantages of heat tracing include cost-effective sensors and ease of data collection...

The use of energy balance models for predicting stream temperature through time and space often focuses heavily on characterizing heat fluxes, while simplifying the hydrologic system by assuming constant discharge through time. However, some streams exhibit diurnal discharge fluctuations due to evapotranspiration, diurnal glacial melt water inputs,...

Tropical glaciers, which are particularly susceptible to global warming, are found in the lower latitudes of Asia and Africa, although 99% of the world’s tropical glaciers are located in the Andes of South America. The lack of seasonality in tropical temperatures, distinct wet and dry seasons, and year-round ablation of these glaciers give rise to...

Road salt used as a deicing agent in winter months has become an emerging contaminant to streams and groundwater. In central New York, road salts are applied heavily during winter months. Recognizing potential sources of salinity to a river may reveal processes controlling the salinization of freshwater systems, with implications for future managem...

A myriad of downstream communities and industries rely on streams fed by both groundwater discharge and glacier meltwater draining the Cordillera Blanca, Northern Peruvian Andes, which contains the highest density of glaciers in the tropics. During the dry season, approximately half the discharge in the region’s proglacial streams comes from ground...

Detrimental effects of road salt runoff on urban streams are compounded by its facilitated routing via storm drains, ditches and flood channels. Elevated in-stream salinity may also result from seasonal storage and discharge of chloride in groundwater, and previous work has hypothesized that groundwater discharge to streams may have the effect of d...

Mountainous regions are integral components of the global hydrologic cycle, driving orographic rainfall patterns and storing water as snow, ice, lakes and groundwater. Within the Cordillera Blanca, Peru this hydrologic system is transforming as a result of increasing temperatures and consequent rapid glacier retreat. The potential impacts on the ti...

Groundwater-surface water interactions in rivers are a critically important factor for fish spawning, as streamwater downwelling or upwelling of low-oxygen groundwater can affect egg survival. Assessing such dynamics at the reach scale using distributed temperature measurements as a tracer proved reliable in determining flux rates and directions in...

Environmental concerns regarding shale gas development include the potential for contamination of potable water sources. These concerns emphasize a need for the development of reliable and efficient means to distinguish waters influenced by Appalachian Basin Brines from other shallower sources (e.g. road salts and animal waste) and the establishmen...

Temperature is a powerful tracer to estimate vertical flows in the hyporheic zone. Temperature time series can be used to obtain estimates of fluid flux, and techniques can be employed to extend these estimates into plan-view flux maps. Key advantages of the use of heat as a tracer include that sensors are inexpensive, and that data can be collecte...

As tropical glaciers rapidly recede in response to climate change, the storage and discharge of groundwater will play an increasing role in regulating river baseflow, particularly during the dry season, when stream flow is currently sustained predominantly by glacial melt. Little is understood regarding the hydrogeologic processes controlling base...

In the tropical Andes, glacial meltwater is an important water resource for downstream communities, especially during the dry season. Due to climate change, glacial retreat is accelerating and straining already limited water resources in the region. It is hypothesized that groundwater storage and discharge will play a critical role in sustaining fu...

Prior work suggests spatial parameters (e.g., landscape position, distance to nearest gas well) can be used to estimate the amount of dissolved methane in domestic drinking water wells overlying the deep Marcellus Shale. New York (NY) provides an opportunity to investigate methane occurrence prior to expansion of high-volume hydraulic fracturing be...

Road salt is an emerging contaminant that is a prominent focus of numerous water quality studies. The Tioughnioga River, located in central New York, is a headwater of the Susquehanna River, which flows into the Chesapeake Bay. In central New York, road salts are applied heavily during winter months. The two branches of the Tioughnioga River with c...

Vertical fluid exchange between surface water and groundwater can be estimated using diurnal signals from temperature time series methods based on amplitude ratios (A r), phase shifts (∆φ), or combined use of both (A r ∆φ). The A r , ∆φ, and A r ∆φ methods are typically applied in conditions where one or more of their underlying assumptions are vio...

Public and regulatory agencies are concerned over the potential for drinking water contamination related to high-volume hydraulic fracturing (hydrofracking) of the Marcellus shale in Pennsylvania and in New York State (NYS), where exploitation of Marcellus gas has not yet begun. Unique natural tracers are helpful for distinguishing the influence of...

Spatially distributed surface temperature is an important, yet difficult to observe, variable for physical glacier melt models. We utilize ground-based thermal infrared imagery to obtain spatially distributed surface temperature data for alpine glaciers. The infrared images are used to investigate thermal micro-scale processes at the glacier surfac...

Analytical solutions to the 1D heat transport equation can be used to derive point measurements of flux between surface water and groundwater from streambed temperature time series. Recent studies have used empirical relationships between measured flux and pointin-time observations of streambed temperatures to produce detailed plan view maps of flu...

Urban streams in the northeastern United States have large road salt inputs during the winter, increased nonpoint sources of inorganic nitrogen, and decreased short-term and permanent storage of nutrients. Restoration activities that re-establish connection between streams and riparian environments may be effective for improving urban stream water...

Tropical glaciers supply approximately half of dry-season stream discharge in glacierized valleys of the Cordillera Blanca, Peru. The remainder of streamflow originates as groundwater stored in alpine meadows and other proglacial geomorphic features. A better understanding of the hydrogeology of alpine groundwater, including sources, storage zones,...

Reach-scale stream restoration with natural channel design is often used to improve stream ecosystem structure and function. Some investigators have studied the effects of restoration on the hyporheic zone, but most used space-for-time substitution instead of comparing the same reach before and after restoration. We examined spatial patterns of hyp...

One-dimensional analytical heat transport equations based on temperature time series data have become popular tools to quantify groundwater-surface water interactions. The influence of nonideal field conditions on the use of these equations has been assessed for nonsinusoidal stream temperature signals, uncertainty in thermal parameters, sensor acc...

While restoring hyporheic flowpaths has been cited as a benefit to stream restoration structures, little documentation exists confirming that constructed restoration structures induce comparable hyporheic exchange to natural stream features. This study compares a stream restoration structure (cross-vane) to a natural feature (riffle) concurrently i...

Groundwater upwelling to streams creates unique habitat by influencing stream water quality and temperature; upwelling zones also serve as vectors for contamination when groundwater is degraded. Temperature time series data acquired along vertical profiles in the streambed have been applied to simple analytical models to determine rates of vertical...

High-volume hydraulic fracturing (HVHF) gas-drilling operations in the Marcellus Play have raised environmental concerns, including risk of groundwater contamination. Fingerprinting water impacted by gas-drilling operations is not trivial given other potential sources of contamination. We present a multivariate statistical modeling framework for de...

The retention capacity for biologically available nitrogen within streams can be influenced by dynamic hyporheic zone exchange, a process that may act as either a net source or net sink of dissolved nitrogen. Over 5 weeks, nine vertical profiles of streambed chemistry (NO3− and NH4+) were collected above two beaver dams along with continuous high-r...

Although there has been recent focus on understanding spatial variability in hyporheic zone geochemistry across different morphological units under baseflow conditions, less attention has been paid to temporal responses of hyporheic zone geochemistry to non-steady-state conditions. We documented spatial and temporal variability of hyporheic zone ge...

Stream restoration goals include improving habitat and water quality through reconstruction of morphological features found at analogous, pristine stream reaches. Enhancing hyporheic exchange may facilitate achieving these goals. Although hyporheic exchange at restoration sites has been explored in a few previous studies, comparative studies of res...

Small dams enhance the development of patchy microenvironments along stream corridors by trapping sediment and creating complex streambed morphologies. This patchiness drives intricate hyporheic flux patterns that govern the exchange of O2 and redox- sensitive solutes between the water column and the stream bed. We used multiple tracer technique...

Natural channel design restoration projects in streams often include the construction of cross-vanes, which are stone, dam-like structures that span the active channel. Vertical hyporheic exchange flux (HEF) and redox-sensitive solutes were measured in the streambed around four cross-vanes with different morphologies. Observed patterns of HEF and r...

: More than 85% of NO3− losses from watersheds in the northeastern United States are exported during winter months (October 1 to May 30). Interannual variability in NO3− loads to individual streams is closely related to interannual climatic variations, particularly during the winter. The objective of our study was to understand how climatic and hyd...

Highlights ► We examined the water sources and flowpaths in two adjacent semi-arid mountain streams. ► Combining isotopes and geochemical tracers is useful in determining watershed hydrology. ► Glaciofluvial terraces and alluvium deposits are important for groundwater recharge and displacement. ► Temporary wetland storage plays an important role in...

It is challenging to quantify reach-scale surface-water–groundwater interactions, while maintaining the fine-scale spatial resolution required in hyporheic studies. One-dimensional heat-transport modeling was used to simulate streambed fluxes at discrete points using time-series temperature records. A predictive relationship was then developed betw...

Highlights ► SW–GW interactions vary temporally, but tools to measure these patterns are limited. ► 1D laboratory column experiments were used to test accuracy of heat tracing model. ► 1D heat transport modeling accurately captures continuous temporal changes in flux. ► Filtering removes artificial temporal flux patterns from perturbed temperature...

There are several methods for determining the spatial distribution and magnitude of groundwater inputs to streams. We compared the results of conventional methods [dye dilution gauging, acoustic Doppler velocimeter (ADV) differential gauging, and geochemical end‐member mixing] to distributed temperature sensing (DTS) using a fibre‐optic cable insta...

Heat is a useful tracer for quantifying groundwater-surface water interaction, but analyzing large amounts of raw thermal data has many challenges. We present a computer program named VFLUX, written in the MATLAB computing language, for processing raw temperature time series and calculating vertical water flux in shallow sub-surface-water systems....

Hyporheic flow can be extremely variable in space and time, and our understanding of complicated flow systems, such as exchange around small dams, has generally been limited to reach-averaged parameters or discrete point measurements. Emerging techniques are starting to fill the void between these disparate scales, increasing the utility of hyporhe...

The Croton Watershed (New York State, USA) is a semi-urban region that provides 10% of the drinking water for the City of New York. Nonpoint source contamination in the watershed is a major concern for managers because the water supply is currently unfiltered water. Results are reported from three synoptic studies of surface water quality from 98 w...

Punctuated head differentials along stream water surface profiles, in conjunction with heterogeneous sediment and complex bedforms, enhance hyporheic exchange, although the magnitude of this exchange is not uniform across the streambed. Patchy biogeochemical micro-environments develop within these complex systems, and are strongly controlled by res...

Small beaver dams enhance the development of patchy micro-environments along the stream corridor by trapping sediment and creating complex streambed morphologies. This generates intricate hyporheic flux patterns that govern the exchange of oxygen and redox sensitive solutes between the water column and the streambed, and exert control on the biogeo...

A characterization of hyporheic exchange for dry and wet season baseflow, as well as partially dewatered discharge, was done in Prieta Creek, a first-order cascade in northern Honduras. The cascade had discharges from 1 to 15 l s−1, had average slopes of 12%, pool spacing of 3 m, and shallow substrate of sand and gravel. Tracer tests were conducted...

1] The conceptual model of hyporheic exchange below river steps may oversimplify exchange flow paths if it depicts a uniform pattern of downstream-directed upwelling. This research used nonmobile, porous bed flume experiments and hydrodynamic simulation (CFD) to characterize hyporheic flow paths below a river step with a hydraulic jump. Bed slope w...

This research examined hydrostatic groundwater model (MODFLOW) predictive adequacy and sensitivity in simulating hyporheic flow paths across a river step with a hydraulic jump. In a companion paper, we used flume and hydrodynamic model analysis to develop a refined conceptual model depicting these flow paths with zones of downwelling and upstream-d...

The rapid exchange of stream water and groundwater across the streambed interface impacts stream ecological function, including the generation of diverse habitat, biogeochemical cycling of nutrients and regulation of stream temperatures. Although these processes have significant impacts on stream systems, quantifying how stream-groundwater interact...

The practice of stream restoration in the U.S. has evolved into a billion dollar industry. Stream restoration goals typically include generation of in-stream habitat or reduced bank erosion, but little is known about how restoration efforts affect hyporheic exchange. Stream restoration projects are often designed based on an analogous reference rea...

Hydrologic retention in stream ecosystems favors the reactions of solutes and nutrients in metabolically active transient storage (MATS) zones. These zones are hot spots where metabolic activity is expected to contribute significantly to ecosystem respiration. We compare the results of a series of coinjections of resazurin (Raz) as a redox sensitiv...

Discharge of groundwater to rivers and streams can be highly variable in space and time and therefore difficult to characterize with the required spatial and temporal resolution. The discharge of highly saline, cool groundwater to Nine Mile Creek, in Syracuse, New York, allowed for comparison between heat and geochemical tracing of surface water-gr...

Natural channel design restoration projects in streams often include the construction of cross-vanes, which are low, stone, dam-like structures that span the active channel. The change in streambed and water elevation over a cross-vane creates a step in static pressure head across the structure. According to modeling studies of similar in-stream st...

As beaver populations increase in the Western United States, beaver dams are becoming more numerous in many incised low-order streams. These dams raise the water table locally, enhancing riparian zone connection and creating pools that increase stream water residence time. Additionally, the stepped drop in stream head over dams enhances hyporheic e...

Small dams enhance hyporheic interaction by creating punctuated head differentials along streams, thereby affecting redox conditions and nutrient cycling in the streambed. As beaver populations return, they create dams that alter hyporheic flowpaths locally, an effect which may integrate at the reach scale to produce a net hydrological and ecologic...