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Surface Water Interactions (surface + water_interaction)

Distribution by Scientific Domains

Engineering	100%

Selected Abstracts

Ground Water/Surface Water Interaction in a Fractured Rock Aquifer

GROUND WATER, Issue 5 2003
Jaime P.A. Oxtobee
In a recent field study of ground water/surface water interaction between a bedrock stream and an underlying fractured rock aquifer, it was determined that the majority of ground water discharge occurred through sparsely located vertical fractures. In this paper, the dominant mechanisms governing ground water/surface water exchange in such an environment are investigated using a numerical model. The study was conducted using several conceptual models based on the field study results. Although the field results provided the motivation for the modeling study, it was not intended to match modeling and field results directly. In addition, the extent of capture zones for discharging or recharging fractures was explored. The results of this study are intended to provide a better understanding of contaminant migration in the vicinity of bedrock streams. Based on the numerical results, the rate of ground water discharge (or recharge) was found to depend on the aperture size of the discharging feature, and on the distribution of hydraulic head with depth within the fracture network. It was determined that the extent of both the capture zone and reverse capture zone for an individual fracture can be extremely large, and will be determined by the height of the stream stage, the fracture apertures of the network, and the hydraulic-head distribution within the network. Because both the stream stage and the hydraulic-head distribution are transient, the size of the capture zone and/or the reverse capture zone for an individual fracture may change significantly over time. As a result, the migration path for contaminants within the fracture network and between the surface and subsurface will also vary significantly with time. [source]

Groundwater Banking in Aquifers that Interact With Surface Water: Aquifer Response Functions and Double-Entry Accounting,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 6 2009
Bryce A. Contor
Contor, Bryce A., 2009. Groundwater Banking in Aquifers That Interact With Surface Water: Aquifer Response Functions and Double-Entry Accounting. Journal of the American Water Resources Association (JAWRA) 45(6):1465-1474. Abstract:, Increasing worldwide demands for water call for mechanisms to facilitate storage of seasonal supplies and mechanisms to facilitate reallocation of water. Markets are economically efficient reallocation and incentive mechanisms when market conditions prevail, but special hydrologic and administrative conditions of water use and allocation interfere with required market conditions. Water banking in general can bring market forces to bear on water storage and reallocation, improving economic efficiency and therefore the welfare of society as a whole. Groundwater banking can utilize advantages of aquifers as storage vessels with vast capacity, low construction cost, and protection of stored water. For groundwater banking in aquifers that interact with surface water, an accounting system is needed that addresses the depletion of stored volumes of water as water migrates to surface water. Constructing such a system requires integration of hydrologic, economic, and legal principles with principles of financial accounting. Simple mass-balance accounting, even with allowances for depletion, is not adequate in these aquifers. Aquifer response functions are mathematical descriptions of the impact that aquifer pumping or recharge events have upon hydraulically connected surface water bodies. Double-entry accounting is a financial accounting methodology for tracking asset inventories and ownership claims upon assets. The powerful innovation of linking aquifer response functions with double-entry accounting technologies allows application of groundwater banking to aquifers where deposits can be depleted by migration to hydraulically connected surface water. It honors the hydrologic realities of groundwater/surface water interaction, the legal requirements of prior appropriation water law, and the economic requirements for equitable and efficient allocation of resources. [source]

A Wet/Wet Differential Pressure Sensor for Measuring Vertical Hydraulic Gradient

GROUND WATER, Issue 1 2010
Brad G. Fritz
Vertical hydraulic gradient is commonly measured in rivers, lakes, and streams for studies of groundwater,surface water interaction. While a number of methods with subtle differences have been applied, these methods can generally be separated into two categories; measuring surface water elevation and pressure in the subsurface separately or making direct measurements of the head difference with a manometer. Making separate head measurements allows for the use of electronic pressure sensors, providing large datasets that are particularly useful when the vertical hydraulic gradient fluctuates over time. On the other hand, using a manometer-based method provides an easier and more rapid measurement with a simpler computation to calculate the vertical hydraulic gradient. In this study, we evaluated a wet/wet differential pressure sensor for use in measuring vertical hydraulic gradient. This approach combines the advantage of high-temporal frequency measurements obtained with instrumented piezometers with the simplicity and reduced potential for human-induced error obtained with a manometer board method. Our results showed that the wet/wet differential pressure sensor provided results comparable to more traditional methods, making it an acceptable method for future use. [source]

Ground Water Modeling Applications Using the Analytic Element Method

GROUND WATER, Issue 1 2006
Randall J. Hunt
Though powerful and easy to use, applications of the analytic element method are not as widespread as finite-difference or finite-element models due in part to their relative youth. Although reviews that focus primarily on the mathematical development of the method have appeared in the literature, a systematic review of applications of the method is not available. An overview of the general types of applications of analytic elements in ground water modeling is provided in this paper. While not fully encompassing, the applications described here cover areas where the method has been historically applied (regional, two-dimensional steady-state models, analyses of ground water,surface water interaction, quick analyses and screening models, wellhead protection studies) as well as more recent applications (grid sensitivity analyses, estimating effective conductivity and dispersion in highly heterogeneous systems). The review of applications also illustrates areas where more method development is needed (three-dimensional and transient simulations). [source]

Interactions between a saline lagoon and a semi-confined aquifer on a salinized floodplain of the lower River Murray, southeastern Australia

HYDROLOGICAL PROCESSES, Issue 24 2009
E. W. Banks
Abstract The transport of saline groundwater from local and regional aquifers to the lower River Murray in South Australia is thought to be greatly influenced by the incised lagoons and wetlands that are present in the adjacent floodplain. Interactions between a saline lagoon and semi-confined aquifer at a floodplain on the River Murray were studied over a 1-year period using hydrogeological techniques and environmental tracers (Cl,, ,2H and ,18O). Piezometric surface monitoring showed that the lagoon acted as a flow-through system intercepting local and regional groundwater flow. A chloride mass balance determined that approximately 70% of the lagoon winter volume was lost by evaporation. A stable isotope mass balance estimated leakage from the lagoon to the underlying aquifer. Around 0,38% of the total groundwater inflow into the lagoon was lost to leakage compared to 62,100% of groundwater inflow lost to evaporation. Overall, floodplain wetlands of the type studied here behave as groundwater flow-through systems. They intercept groundwater discharge, concentrate it and eventually recharge more saline water to the floodplain aquifer. Understanding groundwater,surface water interactions in floodplain wetlands will benefit the effective management of salinity in semi-arid rivers. Copyright © 2009 John Wiley & Sons, Ltd. [source]

The impact of groundwater,surface water interactions on the water balance of a mesoscale lowland river catchment in northeastern Germany

HYDROLOGICAL PROCESSES, Issue 2 2007
Stefan Krause
Abstract The glacially formed northeastern German lowlands are characterized by extensive floodplains, often interrupted by relatively steep moraine hills. The hydrological cycle of this area is governed by the tight interaction of surface water dynamics and the corresponding directly connected shallow groundwater aquifer. Runoff generation processes, as well as the extent and spatial distribution of the interaction between surface water and groundwater, are controlled by floodplain topography and by surface water dynamics. A modelling approach based on extensive experimental analyses is presented that describes the specific water balance of lowland areas, including the interactions of groundwater and surface water, as well as reflecting the important role of time-variable shallow groundwater stages for runoff generation in floodplains. In the first part, experimental investigations of floodplain hydrological characteristics lead to a qualitative understanding of the water balance processes and to the development of a conceptual model of the water balance and groundwater dynamics of the study area. Thereby model requirements which allow for an adequate simulation of the floodplain hydrology, considering also interactions between groundwater and surface water have been characterized. Based on these analyses, the Integrated Modelling of Water Balance and Nutrient Dynamics (IWAN) approach has been developed. This consists of coupling the surface runoff generation and soil water routines of the deterministic, spatially distributed hydrological model WASIM-ETH-I with the three-dimensional finite-difference-based numerical groundwater model MODFLOW and Processing MODFLOW. The model was applied successfully to a mesoscale subcatchment of the Havel River in northeast Germany. It was calibrated for two small catchments (1·4 and 25 km2), where the importance of the interaction processes between groundwater and surface waters and the sensitivity of several controlling parameters could be quantified. Validation results are satisfying for different years for the entire 198 km2 catchment. The model approach was further successfully tested for specific events. The experimental area is a typical example of a floodplain-dominated landscape. It was demonstrated that the lateral flow processes and the interactions between groundwater and surface water have a major importance for the water balance and periodically superimposed on the vertical runoff generation. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Groundwater,surface water interactions in a large semi-arid floodplain: implications for salinity management

HYDROLOGICAL PROCESSES, Issue 16 2005
Sébastien Lamontagne
Abstract Flow regulation and water diversion for irrigation have considerably impacted the exchange of surface water between the Murray River and its floodplains. However, the way in which river regulation has impacted groundwater,surface water interactions is not completely understood, especially in regards to the salinization and accompanying vegetation dieback currently occurring in many of the floodplains. Groundwater,surface water interactions were studied over a 2 year period in the riparian area of a large floodplain (Hattah,Kulkyne, Victoria) using a combination of piezometric surface monitoring and environmental tracers (Cl,, ,2H, and ,18O). Despite being located in a local and regional groundwater discharge zone, the Murray River is a losing stream under low flow conditions at Hattah,Kulkyne. The discharge zone for local groundwater, regional groundwater and bank recharge is in the floodplain within ,1 km of the river and is probably driven by high rates of transpiration by the riparian Eucalyptus camaldulensis woodland. Environmental tracers data suggest that the origin of groundwater is principally bank recharge in the riparian zone and a combination of diffuse rainfall recharge and localized floodwater recharge elsewhere in the floodplain. Although the Murray River was losing under low flows, bank discharge occurred during some flood recession periods. The way in which the water table responded to changes in river level was a function of the type of stream bank present, with point bars providing a better connection to the alluvial aquifer than the more common clay-lined banks. Understanding the spatial variability in the hydraulic connection with the river channel and in vertical recharge following inundations will be critical to design effective salinity remediation strategies for large semi-arid floodplains. Copyright © 2005 John Wiley & Sons, Ltd. [source]