Academic literature on the topic 'SW-GW interaction'

The groundwater (GW) and surface water (SW) interaction (SW-GW) through the hyporheic zone is a significant component in sustainable water resource management. The complexities in SW-GW interactions increase from a local to a regional scale and are affected by variation in hydraulic, hydrologic, and hydrogeologic (3H) processes. Controlling factors and their upscaling of these processes to assess SW-GW interaction have not been addressed sufficiently in previous studies. Additionally, it is unclear what the effective factors are at different scales during the upscaling. Therefore, the present review focused on controlling factors of 3H processes in SW-GW interaction and their upscaling techniques. Relevancy of controlling factors was identified at different scales. Applications of different approaches and their uncertainties were also discussed for the characterization of SW-GW interactions. The study revealed that the improved data from different approaches is crucial for machine learning training and its application in the SW and GW assessment at local, sub-catchment, and catchment scales. Based on the outcomes, a framework has been proposed to execute modalities of controlling factors using remote sensing, geophysics, and artificial intelligence. The proposed framework could help in handling big data and accurate upscaling for water resource management.

The interaction of surface water (SW) and groundwater (GW) is becoming more and more complex under the effects of climate change and human activity. It is of great significance to fully understand the characteristics of regional SW–GW circulation to reveal the water circulation system and the effect of its evolution mechanism to improve the rational allocation of water resources, especially in arid and semi-arid areas. In this paper, Yinchuan Plain is selected as the study area, where the SW–GW interaction is intensive. Three typical profiles are selected to build two-dimensional hydrogeological structure models, using an integrated approach involving field investigation, numerical simulation, hydrogeochemistry and isotope analysis. The SW–GW transformation characteristics are analyzed with these models, showing that geological structure controls the SW–GW interaction in Yinchuan Plain. The SW–GW flow system presents a multi-level nested system including local, intermediate and regional flow systems. The runoff intensity and renewal rate of different flow systems are evidently different, motivating evolution of the hydro-chemical field; human activities (well mining, agricultural irrigation, ditch drainage, etc.) change the local water flow system with a certain impacting width and depth, resulting in a variation of the hydrological and hydro-chemical fields. This study presents the efficacy of an integrated approach combining numerical simulation, hydrogeochemistry and isotope data, as well as an analysis for the determination of GW-SW interactions in Yinchuan Plain.

Surface water and groundwater (SW-GW) are an inseparable whole, having a tightly coupled hydraulic relationship and frequent inter-transformation. As such, the quantitative calculation of water exchange between SW-GW is a difficult challenge. To address this issue, we propose the use of a physically based and distributed hydrological model, called WEP-L, in order to analyze the effects of the SW-GW interaction and its spatiotemporal variation characteristics in the Xiaoqing River basin. We demonstrate that the SW-GW interaction is significantly affected by season. The simulated annual average exchange volume of SW-GW above the control section of Huangtaiqiao Station from 1980 to 2020 is found to be 54.79 m3/s. The exchange volumes of SW-GW in the wet and dry season are 28.69 m3/s and 13.46 m3/s, respectively, accounting for 48.75% and 22.87% of the whole year. In addition, considering two types of climate change scenarios, the exchange capacity of SW-GW increases by 0.42m3/s when the rainfall increases by 5%, while the exchange capacity decreases by only 0.2 m3/s when the temperature increases by 0.2 °C. This study provides insights for the quantification of the SW-GW interaction at the regional scale, which will benefit our understanding of the water cycle and evolution of water resources in Xiaoqing River basin.

Quantifying the spatiotemporal variations of basin-scale surface water (SW)–groundwater (GW) interactions is vital for the conjunctive management of water resources in the basin. In this study, an integrated hydrological model (SWAT-MODFLOW) is used to simulate the SW–GW system in the Huashan Basin. The numerical model was calibrated and validated using the streamflow observations of the watershed outlet and the groundwater levels of the long-term monitoring wells from 2016 to 2020 in the study area. The model results show that the SWAT–MODFLOW can achieve a better fit for the streamflow discharge, compared with the results in the single SWAT model, with R2 (coefficient of correlation) and NSE (Nash-Sutcliffe efficiency coefficient) of 0.85 and 0.83, respectively. The water table fitting results indicate that R2 and RMSE can reach 0.95 and 0.88, respectively. The water budgets analysis demonstrates that the average rate (0.5281 m3/s) of GW abstraction to SW is larger than the rate (0.1289 m3/s) of SW recharge to GW. Moreover, the exchange rate of SW and GW gradually reaches a peak value from June to August, and the lowest value is shown in April, for each hydrological year. Based on the IPPC6 CanESM5 dataset supplied by the Canadian Climate Centre, the regional precipitation scenario subject to climate change was predicted by the ASD (Auto Statistical Downscaling Model) a statistical downscaling method, under the climate scenarios of SSP2_4.5 and SSP5_8.5. The SW–GW interaction pattern was modeled under the future scenarios in the study area. The current (2016–2020) average annual rate of the SW–GW interaction is considered as the base value. Subject to the SSP2_4.5 scenario, the average exchange rate of the SW recharge to GW is 0.1583 m3/s, which is an increase of 22.8%. The average exchange rate of the GW discharge to SW is 0.5189 m3/s which is a reduction of 0.017%. Subject to the SSP5_8.5 scenario, the average exchange rate of SW recharge to GW is 0.1469 m3/s, which is an increase of 14.7%. The average exchange rate of the GW discharge to SW is 0.5953 m3/s, which is an increases of 12.7%. The results can assist in water resource management in the basin, by identifying potential locations of nutrient transport from the aquifer to the river, as well as changes in spatial variability under future climatic conditions.

Abstract The conjunctive use of groundwater and surface water (GW-SW) resources has grown worldwide. Optimal conjunctive water use can be planned by coupling hydrologic models for the simulation of water systems with optimization techniques for improving management strategies. The coupling of simulation and optimization methods constitutes an effective approach to determine sustainable management strategies for the conjunctive use of these water resources; yet, there are challenges that must be addressed. This paper reviews (1) hydrologic models applied for the simulation of GW-SW interaction in the water resources systems, (2) conventional optimization methods, and (3) published works on optimized conjunctive GW-SW use by coupling simulation and optimization methods. This paper evaluates the pros and cons of GW-SW simulation tools and their applications, thus providing criteria for selecting simulation–optimization methods for GW-SW management. In addition, an assessment of GW-SW simulation–optimization tools applied in various studies over the world creates valuable knowledge for selecting suitable simulation–optimization tools in similar case studies for sustainable water resource management under multiple scenarios.

An accurate understanding of the relationship between reservoir construction and the dynamic change of groundwater level in downstream areas is of great significance for rational development and utilization of water resources. At present, the research on the interaction between surface water (SW) and groundwater (GW) mainly focuses on the interaction between river and GW. There are few studies on the impact of the reservoir construction on GW level in downstream loess irrigation area. Rainfall, evaporation and climate temperature have a great impact on W level, but the impact of reservoir construction on the GW level should not be ignored in the utilization of water resources. In this paper, a GW flow model under a natural boundary was established by numerical simulation. Taking Heihe Jinpen Reservoir in Heihe River watershed as the research object, the influence of the construction of a mountain reservoir on the dynamic change of GW level in the downstream loess region is studied. By comparing the GW level under the natural state without reservoir construction and the measured GW level after the reservoir was built, the variation of the GW depth in the loess area of the lower reaches in the Heihe River watershed is obtained. The results show that simulation accuracy of the interaction between SW and GW was reasonable; after the Heihe Jinpen Reservoir construction, the mean GW level decrease was about 6.05 m in the downstream loess irrigation area in Guanzhong Basin. It provides a method for the simulation and prediction of SW–GW conversion laws. This study is also of great significance to explore the change law of the water cycle and improve the utilization rate of water resources.

This study attempts to integrate a Surface Water (SW) model Soil and Water Assessment Tool (SWAT) with an existing steady-state, single layer, unconfined heterogeneous aquifer Analytic Element Method (AEM) based Ground Water (GW) model, named Bluebird AEM engine, for a comprehensive assessment of SW and GW resources and its management. The main reason for integrating SWAT with the GW model is that the SWAT model does not simulate the distribution and dynamics of GW levels and recharge rates. To overcome this issue, often the SWAT model is coupled with the numerical GW model (either using MODFLOW or FEFLOW), wherein the spatial and temporal patterns of the interactions are better captured and assessed. However, the major drawback in integrating the two models (SWAT with—MODFLOW/FEM) is its conversion from Hydrological Response Unit’s (HRU)/sub-basins to grid/elements. To couple them, a spatial translation system is necessary to move the inputs and outputs back and forth between the two models due to the difference in discretization. Hence, for effective coupling of SW and GW models, it may be desirable to have both models with a similar spatial discretization and reduce the need for rigorous numerical techniques for solving the PDEs. The objective of this paper is to test the proof of concept of integrating a distributed hydrologic model with an AEM model at the same spatial units, primarily focused on surface water and groundwater interaction with a shallow unconfined aquifer. Analytic Element Method (AEM) based GW models seem to be ideal for coupling with SWAT due to their innate character to consider the HRU, sub-basin, River, and lake boundaries as individual analytic elements directly without the need for any further discretization or modeling units. This study explores the spatio-temporal patterns of groundwater (GW) discharge rates to a river system in a moist-sub humid region with SWAT-AEM applied to the San Jacinto River basin (SJRB) in Texas. The SW-GW interactions are explored throughout the watershed from 2000–2017 using the integrated SWAT-AEM model, which is tested against stream flow and GW levels. The integrated SWAT-AEM model results show good improvement in predicting the stream flow (R2 = 0.65–0.80) and GW levels as compared to the standalone SWAT model. Further, the integrated model predicted the low flows better compared to the standalone SWAT model, thus accounting for the SW-GW interactions. Almost 80% of the stream network experiences an increase in groundwater discharge rate between 2000 and 2017 with an annual average GW discharge rate of 1853 Mm3/year. The result from the study seems promising for potential applications of SWAT-AEM coupling in regions with considerable SW-GW interactions.

Groundwater-surface water (GW-SW) interaction lengthens hydraulic residence times, increases contact between solutes and biologically active surfaces, and often creates a gradient of redox conditions conducive to an array of biogeochemical processes. As such, the interaction of hydraulic patterns and biogeochemical activity is suspected to be an important determinant of elemental spiraling in streams. Hydrologic interactions may be particularly important in headwater streams, where the extent of the GW-SW mixing environment (i.e., hyporheic zone) is proportionately greater than in larger streams. From our current understanding of stream ecosystem function, we discuss nitrogen (N) spiraling, present a conceptual model of N retention in streams, and use both of these issues to generate specific research questions and testable hypotheses regarding N dynamics in streams.

Abstract. Today there is a great consensus that water resource research needs to become more holistic, integrating perspectives of a large variety of disciplines. Groundwater and surface water (hereafter: GW and SW) are typically identified as different compartments of the hydrological cycle and were traditionally often studied and managed separately. However, despite this separation, these respective fields of study are usually not considered to be different disciplines. They are often seen as different specializations of hydrology with a different focus yet similar theory, concepts, and methodology. The present article discusses how this notion may form a substantial obstacle in the further integration of GW and SW research and management. The article focuses on the regional scale (areas of approximately 103 to 106 km2), which is identified as the scale where integration is most greatly needed, but ironically where the least amount of fully integrated research seems to be undertaken. The state of research on integrating GW and SW research is briefly reviewed and the most essential differences between GW hydrology (or hydrogeology, geohydrology) and SW hydrology are presented. Groundwater recharge and baseflow are used as examples to illustrate different perspectives on similar phenomena that can cause severe misunderstandings and errors in the conceptualization of integration schemes. The fact that integration of GW and SW research on the regional scale necessarily must move beyond the hydrological aspects, by collaborating with the social sciences and increasing the interaction between science and society in general, is also discussed. The typical elements of an ideal interdisciplinary workflow are presented and their relevance with respect to the integration of GW and SW is discussed. The overall conclusions are that GW hydrology and SW hydrogeology study rather different objects of interest, using different types of observation, working on different problem settings. They have thus developed a different theory, methodology and terminology. However, there seems to be a widespread lack of awareness of these differences, which hinders the detection of the existing interdisciplinary aspects of GW and SW integration and consequently the development of a truly unifying interdisciplinary theory and methodology. Thus, despite having the ultimate goal of creating a more holistic approach, we may have to start integration by analyzing potential disciplinary differences. Improved understanding among hydrologists of what interdisciplinary means and how it works is needed. Hydrologists, despite frequently being involved in multidisciplinary projects, are not sufficiently involved in developing interdisciplinary strategies and do usually not regard the process of integration as such as a research topic of its own. There seems to be a general reluctance to apply a (truly) interdisciplinary methodology because this is tedious and few immediate incentives are experienced. The objective of the present opinion paper is to stimulate a discussion rather than to provide recipes on how to integrate GW and SW research or to explain how specific problems of GW–SW interaction should be solved on a technical level. For that purpose it presents complicated topics in a rather simplified, bold way, ignoring to some degree subtleties and potentially controversial issues.

Abstract The spatial and temporal patterns of surface water (SW) - groundwater (GW) exchange are significantly affected by riverbed silting, clogging or erosion processes, by altering the thickness and hydraulic conductivity of riverbed sediments. The duration of SW-GW exchange is controlled by the drainage and infiltration resistance of river bottom sediments (e.g. Andrássy et al., 2012). Generally, these two parameters primarily depend on the hydraulic conductivity and on the thickness of clogged layer. In this study the flow processes between GW and SW were modeled by model TRIWACO for different infiltration resistance and drainage resistance of riverbed sediments. The model area is situated on the Rye Island, which is a lowland area with very low slope. In this area a channel network was built up, where the flow conditions are controlled by water-gates. Because of the low slope and the system of water gates built on the channels, the riverbeds are influenced by intensive clogging processes. First, the applicability of model TRIWACO in the study area was tested by modelling the response of GW on SW level fluctuation. It was simulated, how the regulation of water level and flow direction in the channels influence the GW level, especially in extreme hydrological conditions (drought/flood), and if the GW flow direction and GW level change as it was expected. Next, the influence of channel network silting up on GW-SW interaction was modeled. The thickness of riverbed sediments was measured and their hydraulic conductivity from disturbed sediment samples was evaluated. The assessed hydraulic conductivity was used to calculate the infiltration resistance and the drainage resistance of riverbed sediments in the study area. Then, the GW level and flow direction was simulated for different infiltration resistance and drainage resistance of sediments.

L'evidenza riconosciuta del riscaldamento globale richiede una valutazione del ciclo dell'acqua presente e futuro in Europa e nel mondo. Recentemente, è stata documentata l'evidenza di un regime idrologico modificato nelle Alpi sotto il cambiamento climatico. Tuttavia, secondo il quinto rapporto di valutazione dell'IPCC, è ancora necessario approfondire la nostra comprensione dell'impatto del cambiamento climatico e dell'uso del suolo sullo stoccaggio delle acque sotterranee nei bacini idrografici alpini. Una delle maggiori limitazioni all'analisi dell'interazione tra acque superficiali e sotterranee nei terreni alpini è la difficoltà di acquisizione dei dati e la limitata presenza di stazioni meteorologiche. Questi due fattori aumentano considerevolmente l'incertezza di una rappresentazione olistica dei processi idrologici e una stima affidabile della ricarica delle acque sotterranee. Lo scopo di questo lavoro di ricerca è quello di migliorare le attuali conoscenze sull'interazione tra le acque superficiali e gli acquiferi poco profondi e di definire un metodo per una modellazione integrata delle principali componenti del ciclo dell'acqua a scala di bacino da utilizzare come input per la modellazione delle acque sotterranee. La raccolta e l'uso di dati e metodi che permettono la massima discretizzazione dell'eterogeneità degli elementi coinvolti è il filo conduttore di questo lavoro. L'approccio scientifico è dimostrato per un caso di studio complesso, la valle della Valtellina (Italia settentrionale), per indagare l'interazione tra le componenti del ciclo idrogeologico e le loro proiezioni future secondo le dinamiche climatiche. Questa valle potrebbe essere considerata un perfetto caso di studio perché è caratterizzata da un sistema attivo che reagisce rapidamente alle variazioni meteorologiche e climatiche. Ciò è visibile dalla fluttuazione delle acque sotterranee e del fiume principale, l'Adda, durante eventi estremi di precipitazione e con lo scioglimento della neve durante i periodi di primavera/estate. La tesi è divisa in tre sezioni principali. La prima fornisce una descrizione dell'idrostratigrafia della pianura alluvionale della Valtellina. Questa sezione include il modello di flusso delle acque sotterranee in condizione stazionaria, sviluppato utilizzando FeFlow 7.2, e il relativo processo di calibrazione automatica della parametrizzazione idrogeologica. La seconda mostra la quantificazione del volume di stoccaggio stagionale delle acque sotterranee secondo il metodo del bilancio idrico residuo per due anni idrologici. Per la stima delle componenti principali (Precipitazione, Evapotraspirazione e Snow Water Equivalent), vengono testati nuovi promettenti database e metodi satellitari. L'ultimo capitolo descrive il modello di flusso transitorio delle acque sotterranee sviluppato con condizioni limite dinamiche ottenute dai metodi satellitari. Infine, il modello di flusso è stato utilizzato per valutare l'impatto sulle acque sotterranee di possibili scenari di cambiamento climatico.
The recognized evidence of global warming demands assessment of the present and future water cycle in Europe and worldwide. Recently, evidence of modified hydrological regime in the Alps under climate change has been documented. However, according to the IPCC Fifth Assessment Report, it is still necessary to deepen our understanding of the impact of climate change and land use on groundwater storage in the alpine catchment areas. A major limitation to the analysis of the surface water-groundwater interaction in alpine terrain are the difficultly of data acquisition as well as the limited presence of meteorological stations. These two factors considerably increase the uncertainty of a holistic representation of the hydrological processes and a reliable estimation of groundwater recharge. The aim of this research work is to improve the current knowledge on the interaction between surface water and shallow aquifers and to define a method for an integrated modelling of the main components of the water cycle at the catchment scale to be used as input for groundwater modelling. The collection and use of data and methods that allow for the maximum discretisation of the heterogeneity of the elements involved is the guiding thread of this work. The scientific approach is demonstrated for a complex case study, the Valtellina valley (northern Italy), to investigate the interaction among the components of hydrogeologic cycle and their future projections according to climate dynamics. This valley could be considered a perfect case study because it is characterized by an active system that rapidly reacts to meteorological and climatic variations. This is visible by the fluctuation of the groundwater and of the main river, Adda River, during extreme precipitation events and with snow melts during the spring/summer periods. The thesis is divided into three main sections. The first provides a description of hydro-stratigraphy of the Valtellina valley floodplain. This section includes the groundwater flow model in a steady state condition, developed by using FeFlow 7.2, and the relative automatic calibration process for the hydrogeologic parametrization. 5 The second shows the quantification of seasonal groundwater storage volume according to the residual water budget method for two hydrologic years. For the estimation of the main components (Precipitation, Evapotranspiration and Snow water equivalent), new promising satellite-based database and methods are tested. The last one describes the tranFinally, the flow model has been used to evaluate the impact on groundwater of possible climate change scenarios.sient groundwater flow model developed with dynamic boundary conditions obtained from satellite-based methods.

The study presents the spatio-temporal assessment of groundwater-surface water (GW-SW) interaction aspects in the Schoonspruit River catchment, North West of South Africa. The research study aimed at improving understanding of groundwater and surface water interaction through assessing its location and time when such interaction occurs. GW-SW interaction sites were identified using principal aquifer type characterization methods. The occurrence of the interaction was established using hydrochemistry methods and the effectiveness of the existing monitoring methods were evaluated in their consideration of GW-SW interaction within the study area. The main results from the study showed that there was GW-SW interaction in the Schoonspruit River catchment which was not affected by seasonal changes. The result further showed that existing monitoring methods in the study catchment were not effective in addressing GW-SW interaction. The study concluded that qualitative methods are essential in studying GW-SW interaction and that monitoring methods for such interactions are required
Centre for Sustainable Agriculture and Environmental Sciences
M. Sc. (Environmental Management)

Groundwater system is very vital to humanity and the ecosystem. Aquifers are determined based on the absence or presence of water table positioning, that is, confined, unconfined, leaky aquifers and fractured aquifers. The objective of this chapter is to discuss the characteristic and assessment of groundwater within the scope of vertical distribution of GW, types of the aquifer system, types of SW-GW interface, and SW-GW interaction at both local and regional scales. The properties of the aquifer depend on the physical characteristics of the materials (porosity, permeability, specific yield, specific storage, and hydraulic conductivities) which are determined by techniques like resistivity surveys and pumping tests followed by remote sensing and geographic information system for better information on the groundwater system. Furthermore, understanding the SW-GW interactions through available methods (seepage meter, heat tracer, and environmental tracer) is useful in watershed management, that is, risk management and assessment of the aquifer system.