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1.
Relation of streams, lakes, and wetlands to groundwater flow systems   总被引：24，自引：10，他引：14  
 Surface-water bodies are integral parts of groundwater flow systems. Groundwater interacts with surface water in nearly all landscapes, ranging from small streams, lakes, and wetlands in headwater areas to major river valleys and seacoasts. Although it generally is assumed that topographically high areas are groundwater recharge areas and topographically low areas are groundwater discharge areas, this is true primarily for regional flow systems. The superposition of local flow systems associated with surface-water bodies on this regional framework results in complex interactions between groundwater and surface water in all landscapes, regardless of regional topographic position. Hydrologic processes associated with the surface-water bodies themselves, such as seasonally high surface-water levels and evaporation and transpiration of groundwater from around the perimeter of surface-water bodies, are a major cause of the complex and seasonally dynamic groundwater flow fields associated with surface water. These processes have been documented at research sites in glacial, dune, coastal, mantled karst, and riverine terrains. Received, April 1998 · Revised, July 1998, August 1998 · Accepted, September 1998  相似文献   

2.
Quantifying water exchange between a coastal wetland and the underlying groundwater is important for closing water, energy and chemical budgets. The coastal wetlands of the Florida Everglades (USA) are at the forefront of a large hydrologic restoration project, and understanding of groundwater/surface-water interactions is needed to comprehend the effects of the project. Four independent techniques were used to identify water exchange at varying spatial and temporal scales in Taylor Slough, Everglades National Park. The techniques included a water-budget study and measurements of hydraulic head gradients, geochemical tracers, and temperature. During the 18-month study, the four methods converged as to the timing of groundwater discharge, typically between June and September, contemporaneous with the wet season and increasing surface-water levels. These results were unexpected, as groundwater discharge was predicted to be greatest when surface-water levels were low, typically during the dry season. Either a time lag of 1?C5?months in the response of groundwater discharge to low surface-water levels or precipitation-induced groundwater discharge may explain the results. Groundwater discharge was a significant contributor (27?%) to the surface water in Taylor Slough with greater rates of discharge observed towards the coastline in response to seawater intrusion.  相似文献   

3.
Correct understanding of groundwater/surface-water (GW–SW) interaction in karst systems is of greatest importance for managing the water resources. A typical karst region, Fangshan in northern China, was selected as a case study. Groundwater levels and hydrochemistry analyses, together with isotope data based on hydrogeological field investigations, were used to assess the GW–SW interaction. Chemistry data reveal that water type and the concentration of cations in the groundwater are consistent with those of the surface water. Stable isotope ratios of all samples are close to the local meteoric water line, and the 3H concentrations of surface water and groundwater samples are close to that of rainfall, so isotopes also confirm that karst groundwater is recharged by rainfall. Cross-correlation analysis reveals that rainfall leads to a rise in groundwater level with a lag time of 2 months and groundwater exploitation leads to a fall within 1 month. Spectral analysis also reveals that groundwater level, groundwater exploitation and rainfall have significantly similar response periods, indicating their possible inter-relationship. Furthermore, a multiple nonlinear regression model indicates that groundwater level can be negatively correlated with groundwater exploitation, and positively correlated with rainfall. The overall results revealed that groundwater level has a close correlation with groundwater exploitation and rainfall, and they are indicative of a close hydraulic connection and interaction between surface water and groundwater in this karst system.  相似文献   

4.
Hydrological interactions between surface water and groundwater (GW) can be described using hydrochemical and biological methods. Surface water–groundwater interactions and their effects on groundwater invertebrate communities were studied in the Nakdong River floodplain in South Korea. Furthermore, the GW-Fauna-Index, a promising new index for assessing the strength of surface-water influence on groundwater, was tested. The influence of surface water on groundwater decreased with increasing depth and distance from the river. While hydrochemistry prevailingly reflected the origin of the waters in the study area (i.e. whether alluvial or from adjacent rock), faunal communities seemed to display an affinity to surface-water intrusion. Fauna reacted quickly to changes in hydrology, and temporal changes in faunal community structure were significantly linked to the hydrological situation in the floodplain. The metazoan faunal community and the GW-Fauna-Index allow a distinction between surface and subsurface waters with varying degrees of exchange. The results indicate that hydrological conditions are reflected by faunal assemblages on a high spatiotemporal resolution, and that surface-water intrusion can be estimated using the GW-Fauna-Index.  相似文献   

5.
Studies of hot springs have focused mainly on the properties of fluids and solids. Fewer studies focus on the relationship between the hot springs and groundwater/surface-water environments. The differences in temperature and dissolved solids between hot-spring water and typical surface water and groundwater allow interactions to be traced. Electromagnetic terrain (EMT) conductivity is a nonintrusive technique capable of mapping mixing zones between distinct subsurface waters. These interactions include zones of groundwater/surface-water exchange and groundwater mixing. Herein, hydrogeological techniques are compared with EMT conductivity to trace hot-spring discharge interactions with shallow groundwater and surface water. Potentiometric-surface and water-quality data determined the hydrogeochemistry of two thermally influenced areas in Yellowstone National Park, Wyoming (USA). Data from the sites revealed EMT conductivity contrasts that reflected the infiltration of conductive hot-spring discharge to local groundwater systems. The anomalies reflect higher temperatures and conductivity for Na+–Cl?-rich hydrothermal fluids compared to the receiving groundwater. EMT conductivity results suggested hot springs are fed by conduits largely isolated from shallow groundwater; mixing of waters occurs after hot-spring discharge infiltrates groundwater from the surface and, generally, not by leakage in the subsurface. A model was proposed to explain the growth of sinter mounds.  相似文献   

6.
Understanding the processes controlling groundwater/surface-water interaction is essential for effective resource management and for protecting sensitive ecosystems. Through intensive monitoring of Chalk groundwater, shallow gravel groundwater and surface water in the River Lambourn, UK, using a combination of hydrochemical and hydrophysical techniques, a complex pattern of interactions has been elucidated. The river is broadly in hydraulic contact with the streambed sediments and adjacent gravels and sands, but these deposits are mainly hydraulically separate from the underlying Chalk at the site. The hydraulic relationship between the river and underlying alluvium is variable, involving components of groundwater flow both parallel and transverse to the river and with both effluent and influent behaviour seen. While the gravel aquifer is significant in controlling groundwater/surface-water interaction, its importance as a route for flow down the catchment is likely to be modest compared with river discharge. The hydrological complexity revealed in a geological setting typical of lowland UK Chalk streams has implications both for investigation methods and for management such as in the setting of environmental objectives in the European Water Framework Directive.  相似文献   

7.
Little is known of the interactions between groundwater and surface water on deeply weathered landscapes of low relief in the Great Lakes Region of Africa (GLRA). The role of groundwater in sustaining surface-water levels during periods of absent rainfall is disputed and groundwater is commonly excluded from estimations of surface-water balances. Triangulated piezometers installed beside lake gauging stations on Lake Victoria and Lake Kyoga in Uganda provide the first evidence of the dynamic interaction between groundwater and surface water in the GLRA. Stable isotope ratios (2H:1H, 18O:16O) support piezometric evidence that groundwater primarily discharges to lakes but show further that mixing of groundwater and lake water has occurred at one site on Lake Victoria (Jinja). Layered-aquifer heterogeneity, wherein fluvial-lacustrine sands overlie saprolite, gives rise to both rapid and slow groundwater fluxes to lakes which is evident from the recession of borehole hydrographs following recharge events. Darcy throughflow calculations suggest that direct contributions from groundwater to Lake Victoria comprise <1% of the total inflows to the lake. Groundwater/surface-water interactions are strongly influenced by changing drainage base (lake) levels that are controlled, in part, by regional climate variability and dam releases from Lake Victoria (Jinja).  相似文献   

8.

Over-exploited groundwater is expected to remain the predominant source of domestic water in suburban areas of Hanoi, Vietnam. In order to evaluate the effect on groundwater recharge, of decreasing surface-water bodies and land-use change caused by urbanization, the relevant groundwater systems and recharge pathways must be characterized in detail. To this end, water levels and water quality were monitored for 3 years regarding groundwater and adjacent surface-water bodies, at two typical suburban sites in Hanoi. Stable isotope (δ18O, δD of water) analysis and hydrochemical analysis showed that the water from both aquifers and aquitards, including the groundwater obtained from both the monitoring wells and the neighboring household tubewells, was largely derived from evaporation-affected surface-water bodies (e.g., ponds, irrigated farmlands) rather than from rivers. The water-level monitoring results suggested distinct local-scale flow systems for both a Holocene unconfined aquifer (HUA) and Pleistocene confined aquifer (PCA). That is, in the case of the HUA, lateral recharge through the aquifer from neighboring ponds and/or irrigated farmlands appeared to be dominant, rather than recharge by vertical rainwater infiltration. In the case of the PCA, recharge by the above-lying HUA, through areas where the aquitard separating the two aquifers was relatively thin or nonexistent, was suggested. As the decrease in the local surface-water bodies will likely reduce the groundwater recharge, maintaining and enhancing this recharge (through preservation of the surface-water bodies) is considered as essential for the sustainable use of groundwater in the area.

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9.
The hydrodynamics of tree islands during the growth of newly planted trees has been found to be influenced by both vegetation biomass and geologic conditions. From July 2007 through June 2009, groundwater and surface-water levels were monitored on eight recently planted tree islands at the Loxahatchee Impoundment Landscape Assessment (LILA) facility in Boynton Beach, Florida, USA. Over the 2-year study, stand development coincided with the development of a water-table depression in the center of each of the islands that was bounded by a hydraulic divide along the edges. The water-table depression was greater in islands composed of limestone as compared to those composed of peat. The findings of this study suggest that groundwater evapotranspiration by trees on tree islands creates complex hydrologic interactions between the shallow groundwater in tree islands and the surrounding surface water and groundwater bodies.  相似文献   

10.
Ecohydrology of Groundwater Dependent Ecosystems: A Review   总被引：2，自引：0，他引：2  
Groundwater Dependent Ecosystems (GDEs) are ecosystems that must have access to groundwater to maintain their ecological structure and function. In other words, the vegetation dynamics moisture dynamics, and water-salt balance in GDEs are significantly affected by and directly related to the groundwater. This work reviews the most recent research advances in the ecohydrology of GDEs from: ①the interactions between groundwater and vegetation, ②the interactions between groundwater and soil moisture dynamics in the vadose zone, the interactions between ground and ③surface-water systems, ④the interactions between groundwater and salt accumulation dynamics, ⑤the responses of GDEs to climate changes and human disturbances, and ⑥the ecohydrological modeling works toward sustainable management of GDEs. It is pointed out that several issues need to be taken into account in the managements of GDEs, i.e., how does the vegetation of GDEs response to fluctuations and decreases in the groundwater level, whether there is a catastrophic loss of the functions of GDEs, and what is the threshold value below which such a catastrophe may occur. The key to solving those issues lies in how to delineate the different ecohydrological processes occurred in the soil medium from the top of the ground surface to the water table. Therefore, observation and modeling efforts are needed and will be important research priorities in the future, especially for GDEs in arid environments. We also argued that four more difficulties should be addressed towards sustainable management of GDEs in future: ①how to identify GDEs in the field, and determine which habitats and species are reliant on groundwater for their persistence in the landscape, ②what groundwater regime is required to sustain the existence of GDEs, ③how to manage GDEs with limited social resources, and ④what measures of ecosystem function can be monitored to determine that management is effective?  相似文献   

11.

The Mio-Pliocene aquifer of the coastal sedimentary basin of Benin is the most exploited aquifer for water supply to the urbanised region in the southern part of the country. The population explosion is putting increasing pressure on quantitative and qualitative aspects of the groundwater resources. Preventing groundwater contamination caused by surface waters requires a thorough understanding of surface-water/groundwater interactions, especially the interactions between the Mio-Pliocene aquifer and surface waters. This study aimed to investigate the interactions between groundwater and surface waters along the major rivers (Sô River and Ouémé Stream) and brooks in the Ouémé Delta. Field campaigns identified 75 springs located in the valleys which feed the rivers, and thus maintain their base flow. The piezometric results indicated, through flow direction assessment, that the Mio-Pliocene aquifer feeds Ouémé Stream and Sô River. Chemical analyses of groundwater and surface waters show similar chemical facies, and changes in the chemical composition in groundwater are also observed in the surface waters. Moreover, the isotopic signatures of surface waters are similar to those of the groundwater and springs, which led to the identification of potential groundwater discharge areas. As a result of groundwater discharge into surface waters, the fraction of groundwater in the surface water is more than 66% in the brooks, regardless of the season. In the Ouémé Stream and Sô River, the fraction of groundwater is 0–21% between June and September, while from October to March it is 47–100%.

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12.
Calcium concentration and calcite supersaturation (Ω) needed for calcium carbonate nucleation and crystal growth in Pyramid Lake (PL) surface water were determined during August of 1997, 2000, and 2001. PL surface water has Ω values of 10–16. Notwithstanding high Ω, calcium carbonate growth did not occur on aragonite single crystals suspended PL surface water for several months. However, calcium solution addition to PL surface-water samples caused reproducible calcium carbonate mineral nucleation and crystal growth. Mean PL surface-water calcium concentration at nucleation was 2.33 mM (n = 10), a value about nine times higher than the ambient PL surface-water calcium concentration (0.26 mM); mean Ω at nucleation (109 with a standard deviation of 8) is about eight times the PL surface-water Ω. Calcium concentration and Ω regulated the calcium carbonate formation in PL nucleation experiments and surface water. Unfiltered samples nucleated at lower Ω than filtered samples. Calcium concentration and Ω at nucleation for experiments in the presence of added particles were within one standard deviation of the mean for all samples. Calcium carbonate formation rates followed a simple rate expression of the form, rate (mM/min) = A (Ω) + B. The best fit rate equation “Rate (Δ mM/Δ min) = −0.0026 Ω + 0.0175 (r = 0.904, n = 10)” was statistically significant at greater than the 0.01 confidence level and gives, after rearrangement, Ω at zero rate of 6.7. Nucleation in PL surface water and morphology of calcium carbonate particles formed in PL nucleation experiments and in PL surface-water samples suggest crystal growth inhibition by multiple substances present in PL surface water mediates PL calcium carbonate formation, but there is insufficient information to determine the chemical nature of all inhibitors.  相似文献   

13.
Muzaffarnagar is an economically rich district situated in the most fertile plains of two great rivers Ganga and Yamuna in the Indo-gangetic plains, with agricultural land irrigated by both surface water as well as groundwater. An investigation has been carried out to understand the hydrochemistry of the groundwater and its suitability for irrigation uses. Groundwater in the study area is neutral to moderately alkaline in nature. Chemistry of groundwater suggests that alkaline earths (Ca + Mg) significantly exceed the alkalis (Na + K) and weak acids exceed the strong acids (Cl + SO4), suggesting the dominance of carbonate weathering followed by silicate weathering. Majority of the groundwater samples (62%) posses Ca–Mg–HCO3 type of hydrochemical species, followed by Ca–Na–Mg–HCO3, Na–Ca–Mg–HCO3, Ca–Mg–Na–HCO3–Cl and Na–Ca–HCO3–SO4 types. A positive high correlation (r 2 = 0.928) between Na and Cl suggests that the salinity of groundwater is due to intermixing of two or more groundwater bodies with different hydrochemical compositions. Barring a few locations, most of the groundwater samples are suitable for irrigation uses. Chemical fertilizers, sugar factories and anthropogenic activities are contributing to the sulphate and chloride concentrations in the groundwater of the study area. Overexploitation of aquifers induced multi componential mixing of groundwater with agricultural return flow waters is responsible for generating groundwater of various compositions in its lateral extent.  相似文献   

14.
Identification and quantification of groundwater and surface-water interactions provide important scientific insights for managing groundwater and surface-water conjunctively. This is especially relevant in semi-arid areas where groundwater is often the main source to feed river discharge and to maintain groundwater dependent ecosystems. Multiple field measurements were taken in the semi-arid Bulang sub-catchment, part of the Hailiutu River basin in northwest China, to identify and quantify groundwater and surface-water interactions. Measurements of groundwater levels and stream stages for a 1-year investigation period indicate continuous groundwater discharge to the river. Temperature measurements of stream water, streambed deposits at different depths, and groundwater confirm the upward flow of groundwater to the stream during all seasons. Results of a tracer-based hydrograph separation exercise reveal that, even during heavy rainfall events, groundwater contributes much more to the increased stream discharge than direct surface runoff. Spatially distributed groundwater seepage along the stream was estimated using mass balance equations with electrical conductivity measurements during a constant salt injection experiment. Calculated groundwater seepage rates showed surprisingly large spatial variations for a relatively homogeneous sandy aquifer.  相似文献   

15.
Understanding water exchange between groundwater and streams, or groundwater/surface-water relationships, is of primary importance for solving conflicts related to water use and for restoring water ecosystems. To this end, a combination of classic geochemical tools and isotopic tools were tested on the Bassée study site, located in the alluvial plain of the River Seine, to see whether they are relevant for tracing multiple and complex groundwater/surface-water relationships. The Ca/Sr ratio associated with Sr isotopes shows contrasted values and suggests that infiltration of surface water to groundwater increases when approaching the Seine. Furthermore, stable isotopes of the water molecule indicate that water from gravel-pit lakes may infiltrate into groundwater. Tritium and CFC tools confirmed surface-water influence on the Alluvial and Chalk aquifers. This geochemical approach, tested on the Bassée site, clearly demonstrates the need of using various geochemical tools for describing groundwater/surface-water relationships, and can be conclusively addressed to other case studies for helping decision makers in their management of natural water resources.  相似文献   

16.
This report summarizes research studies linking on-site waste disposal systems (OSDS) to pathogen and nutrient concentrations in groundwater with the potential to impact coastal embayments. Few studies connect OSDS to coastal water quality. Most studies examined pathogen and nutrient impacts to groundwater and omitted estimations of contaminants discharged to surface water. The majority of studies focused on nitrogen, with little information on pathogens and even less on phosphorus. Nitrogen discharged from OSDS poses the greatest threat to water quality. Vertical distance of septic tank infiltration system from the water table, septic system design, and siting remain the key components in minimizing potential impacts from OSDS for control of both pathogens and nutrients. The most comprehensive information connecting nutrient contributions from OSDS to surface water quality was the study conducted on Buttermilk Bay in Massachusetts where 74% of nitrogen to the bay was attributed to onsite disposal systems. In conclusion, further studies on the viability and transport of pathogens and nutrients through the groundwater aquifer and across the groundwater/surface-water interface are needed. Additional research on the importance of septic system design on the availability of contaminants to groundwater as well as the minimum distance between the septic system and water table necessary to protect groundwater are also indicated.  相似文献   

17.
In terms of the research on groundwater–surface water heat-tracing methods, investigation of the interactions within the compound system of the groundwater–surface water–hyporheic zone can effectively reveal the relevant physicochemical processes and microbial properties. The evaluation of these properties represents a key component in qualitative and quantitative research on groundwater–surface water interactions. Therefore, this paper reviews the research results on groundwater–surface water interactions achieved by related researchers using heat as a natural tracer over the last decade. In connection with the application of heat-tracing theory to the basic principles of hyporheic exchange between groundwater and surface water, research on groundwater–surface water interaction through one-dimensional steady-state and transient-state heat transport analytical models, techniques to collect and analyze temperature time series data, and numerical simulation technology is reviewed. In addition, directions for future research using groundwater–surface water heat-tracing methods are suggested. First, hypothetical, difficult temperature boundary and hydrogeological conditions require further research. Second, hydrodynamic exchange capacity and the processes of heat exchange and solute concentration exchange in the hyporheic zone alongside riverbeds should be appropriately and accurately measured under multi-scale influences. Third, the overall study of the heat transport process inside the hyporheic zone induced by complex riverbed forms should be performed, and the response mechanism of riverbed hyporheic exchanges driven by riverbed form, the hydrodynamic force of surface water, and sediment permeability should be revealed. The objectives and goals of this paper are to encourage scholars interested in analyzing groundwater–surface water interactions using heat as a tracer to creatively solve practical problems and to improve the ecological functions of river aquatic habitats through new research results.  相似文献   

18.
The Andean region is characterized by important intramontane alluvial and glacial valleys; a typical example is the Tarqui alluvial plain, Ecuador. Such valley plains are densely populated and/or very attractive for urban and infrastructural development. Their aquifers offer opportunities for the required water resources. Groundwater/surface-water (GW–SW) interaction generally entails recharge to or discharge from the aquifer, dependent on the hydraulic connection between surface water and groundwater. Since GW–SW interaction in Andean catchments has hardly been addressed, the objectives of this study are to investigate GW–SW interaction in the Tarqui alluvial plain and to understand the role of the morphology of the alluvial valley in the hydrological response and in the hydrological connection between hillslopes and the aquifers in the valley floor. This study is based on extensive field measurements, groundwater-flow modelling and the application of temperature as a groundwater tracer. Results show that the morphological conditions of a valley influence GW–SW interaction. Gaining and losing river sections are observed in narrow and wide alluvial valley sections, respectively. Modelling shows a strong hydrological connectivity between the hillslopes and the alluvial valley; up to 92 % of recharge of the alluvial deposits originates from lateral flow from the hillslopes. The alluvial plain forms a buffer or transition zone for the river as it sustains a gradual flow from the hills to the river. Future land-use planning and development should include concepts discussed in this study, such as hydrological connectivity, in order to better evaluate impact assessments on water resources and aquatic ecosystems.  相似文献   

19.
The modeling of changes in surface water and groundwater in the areas of inter-basin water diversion projects is quite difficult because surface water and groundwater models are run separately most of the time and the lack of sufficient data limits the application of complex surface-water/groundwater coupling models based on physical laws, especially for developing countries. In this study, a distributed surface-water and groundwater coupling model, named the distributed time variant gain model–groundwater model (DTVGM-GWM), was used to assess the influence of climate change and inter-basin water diversion on a watershed hydrological cycle. The DTVGM-GWM model can reflect the interaction processes of surface water and groundwater at basin scale. The model was applied to the Haihe River Basin (HRB) in eastern China. The possible influences of climate change and the South-to-North Water Diversion Project (SNWDP) on surface water and groundwater in the HRB were analyzed under various scenarios. The results showed that the newly constructed model DTVGM-GWM can reasonably simulate the surface and river runoff, and describe the spatiotemporal distribution characteristics of groundwater level, groundwater storage and phreatic recharge. The prediction results under different scenarios showed a decline in annual groundwater exploitation and also runoff in the HRB, while an increase of groundwater storage and groundwater level after the SNWDP’s operation. Additionally, as the project also addresses future scenarios, a slight increase is predicted in the actual evapotranspiration, soil water content and phreatic recharge. This study provides valuable insights for developing sustainable groundwater management options for the HRB.  相似文献   

20.
Groundwater–surface water (GW–SW) interactions cover a broad range of hydrogeological and biological processes and are controlled by natural and anthropogenic factors at various spatio-temporal scales, from watershed to hyporheic/hypolentic zone. Understanding these processes is vital in the protection of groundwater-dependent ecosystems increasingly required in water resources legislation across the world. The use of environmental tracers and indicators that are relevant simultaneously for groundwater, surface water and biocenoses–biotope interactions constitutes a powerful tool to succeed in the management task. However, tracer type must be chosen according to the scale of interest and tracer use thus requires a good conceptual understanding of the processes to be evaluated. This paper reviews various GW–SW interaction processes and their drivers and, based on available knowledge, systemises application of conservative tracers and semi-conservative and reactive environmental indicators at different spatial scales. Biocenoses–biotopes relationships are viewed as a possible transition tool between scales. Relation between principal application of the environmental tracers and indicators, examples and guidelines are further proposed for examining GW–SW interactions from a hydrogeological and biological point of view by demonstrating the usability of the tracers/indicators and providing recommendations for the scientific community and decision makers.  相似文献   

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