Xu-Sheng Wang

• PhD
• Professor at China University of Geosciences (Beijing)

A surface water body fed by groundwater is normally known as a terminal place of groundwater flow systems originating from precipitation recharge on highlands. The theory of Tóth predicted that these flow systems form a hierarchically nested structure of groundwater circulation in a composite basin. In this study, we will report new flow paths amon...

Climate warming has caused increased air temperature as well as increased subsurface temperature. Many previous studies on subsurface warming simplified heat advection by neglecting the horizontal component of regional groundwater flow or even neglected heat advection accompanying groundwater flow. In this study, the simultaneous control of heat ad...

As an indicator of the renewability of a groundwater basin, the spatial distribution of groundwater age has attracted intensive research. As reported in the literature, 3H measurements in 74 US aquifers showed pumping-induced groundwater rejuvenation, whereas 14C ages in two heavily developed aquifers in France and China indicated pumping-induced g...

Inter-basin groundwater flow (IGF), defined as groundwater flows across the topographic divides, occurs in nature as a common phenomenon, and seriously affect water balance and solute transport in a basin. Although the existence of IGF has been checked in drainage basins with indirect methods, such as using information of hydrogeochemistry, few stu...

The changes in climate and catchment properties have altered the hydrological processes significantly at different spatiotemporal scales around the world. In particular for finer time scales, changes in water storage, which has been commonly neglected for long‐term temporal scales, may play an important role on hydrological processes. Nevertheless,...

As a widely employed method for in situ remediation of groundwater contamination, the pump-and-treat (PAT) system involves the management of water recirculation between the extraction and injection wells. The recirculation zone (RZ) of an extraction-injection well pair in a confined aquifer has been well known. However, PAT systems are more frequen...

在区域尺度上,地下水流的路径存在跨越地表分水岭的可能性,从而形成跨流域地下水循环,影响流域之间的水文关系和溶质输送过程。跨流域地下水循环的研究在国际上尚处于起步阶段,方兴未艾,目前已经取得的进展是一个值得关注的问题。对近20年来国内外跨流域地下水循环的研究文献进行了系统的跟踪分析,从形成机理、识别方法和影响评估3个角度总结现有的研究进展。在水动力学形成机理方面,已经从理论上确定了地表分水岭、潜水面最高点和地下水流系统分水点之间的偏离特征,为划分河流之间的多种跨流域地下水循环路径提供了依据。在跨流域地下水循环的识别方面,一系列实际流域的案例提供了可以借鉴的方法,包括水均衡法、流域水文模型和水文地球化学端元混合模型等,证实了跨流域地下水循环的存在性,甚至评估出其循环通量,深化了流域水量平衡关系的...

Digital rock twins are widely used to obtain hydraulic properties of porous media by simulating pore-scale fluid flow. Multifractal characteristics of pore geometry and flow velocity distribution have been discovered with two-dimensional (2D) images and three-dimensional (3D) models, whereas the dependency of results on the resolution is not well k...

Identifying dominant water stress on vegetation growth over the arid basins is essential to better understand ecosystems and water interactions, which are fundamental in managing regional water resources. The Kongqi River basin is an ecologically sensitive area with limited water resources in the northern part of Tarim Basin in northwest China. How...

大气降水的氢氧同位素含量具有高程效应，降水入渗后参与地下水循环，其高程效应如何受地下水流系统的影响转 化为地下水氢氧同位素的深度效应？现有研究对于这个问题缺少定量认识。文章构建单向倾斜盆地和双峰波状盆地的稳 态地下水循环理论模型，采用MODFLOW模拟剖面二维地下水流场、采用MT3DMS模拟重同位素分子的对流-弥散过程， 得到地下水D和 18 O含量的空间分布，探讨了氢氧同位素高程效应在地下水流系统转化为深度效应的机理。结果表明：在 单斜盆地，补给区大气降水D和 18 O含量的高程效应转化为排泄区地下水δD和δ 18 O值随埋深增大而指数型衰减的深度效 应；在双峰波状盆地，当含水层渗透性相对入渗强度较大时(K 0 /w=1 000)，仅发育一个区域地下水流系统，在区域地下水的 排泄区δD和δ...

Intensive groundwater exploitation has depleted groundwater storage and led to a series of geo-environmental problems in Beijing Plain, China. Managed Aquifer Recharge (MAR) has been endorsed to mitigate the groundwater storage depletion and achieve groundwater sustainability. A pilot MAR has been tested in the Chaobai River catchment since 2015. A...

The estimation of actual evapotranspiration is a difficult issue in hydrological research, particularly in the scarcely observed region. Deep learning (DL) has been increasingly used in the field of hydrology in recent years. In this study, we investigated the ability of DL on actual evapotranspiration estimation using three sets of controlled expe...

Lithium (Li) isotopes have shown large potential in tracing weathering in various water bodies, but there is limited study on Li isotopes in subsurface conditions where CO2 has been largely consumed. In this study, we use a thick sandstone aquifer in the Ordos Basin, NW China, as a natural setting to investigate the behaviors of Li isotopes in hydr...

Causes and water sources of flowing artesian wells attracted the interest of many hydrogeologists throughout history, however, a quantitative model that satisfactorily considers the roles of topography, groundwater recharge/discharge and aquitards on hydraulics of flowing wells is still lacking. In this study, a three-layer river-valley basin with...

Croplands can significantly influence the hydrologic response of catchments to climate change in a region but such influence has not been well investigated and quantified. In this study, we firstly use the conceptual hydrological model to investigate the annual water balance for croplands-altered catchments, and the “natural” state without cropland...

Groundwater influences the water and carbon cycle by supplying moisture to plants in the semi-arid and arid zones. However, little is known about the response of ecosystem water use efficiency (WUE) to climate change in different groundwater depth (GD) sections. Recent research has shown that plant photosynthesis and growth are closely related to G...

There is an increasing interest in identifying soil hydraulic properties from simplified evaporation experiments. However, the conventional simplified evaporation method includes a deficit due to using the linear assumption and not accounting for uncertainty in parameters. A suggested alternative method is assessing the parameter uncertainties thro...

Hierarchically nested groundwater flow systems have been widely investigated by numerical modeling and laboratory experiments but seldom recognized from in situ observations and testing. Groundwater age and geochemical profiles were obtained by the authors using a packer system along two wellbores drilled in the Ordos Plateau, China. Groundwater ag...

Climate change has been concerned as a trigger of hydrologic changes around the world. Budyko framework was widely used in hydrologic sensitivity analyses on the steady‐state water balance. The unsteady‐state responses, for example the inter‐annual hydrologic sensitivity, were not well investigated, especially for catchments influenced by croplands...

A coupled regional and local model is required when groundwater flow and solute transport are to be simulated in local areas of interest with a finer grid while regional aquifer boundary and major stresses should be retained with a coarser grid. The coupled model should also maintain interactions between the regional and local flow systems. In the...

Freezing-induced groundwater-level decline is widely observed in regions with a shallow water table, but many existing studies on freezing-induced groundwater migration do not account for freezing-induced water-level fluctuations. Here, by combining detailed field observations of liquid soil water content and groundwater-level fluctuations at a sit...

In the hydrologic cycle, sandy soils play the role of a connecting reservoir of surface water and groundwater, particularly in arid areas. Therefore, to provide water conservation and ecological environment protection, it is important to study the soil water behavior in the unsaturated zone. At present, the CT-scan method is commonly used to study...

The rise and fall of the groundwater level can drive air flow in the vadose zone. In turn, the air flow can interact with the water flow. When the unconfined aquifer is covered by a low-permeability media, the coupling of the water flow and the air flow is more obvious. In this study, a conceptual model is established for coupling of air flow and w...

Three alternative groundwater flow models were evaluated for Beijing Plain, China. The first model (AM1) was constructed with the “thin layer approach” in which all 9 model layers, including five aquifers separated by four aquitards, are continuously present in the same model area. The second model (AM2) was constructed with the “quasi-3D approach”...

Freezing-induced water migration and groundwater level decline are widely observed in regions with shallow water table, but many existing studies trying to quantify freezing-induced groundwater migration do not account for water level fluctuations induced by freezing and thawing. Here, detailed field observations of liquid soil water content and gr...

The groundwater divide is a key feature of river basins and significantly influenced by subsurface hydrological processes. For an unconfined aquifer between two parallel rivers or ditches, it has long been defined as the top of the water table based on the Dupuit–Forchheimer approximation. However, the exact groundwater divide is subject to the int...

Improved understanding of interactions among the atmosphere, soil water and groundwater can be achieved by observing time-series of soil-water content and water-table fluctuations in a soil profile. Field observations at a site in China show that from mid-June to mid-September, when evapotranspiration is strong, direct groundwater recharge does not...

As important sensitive feedback of ecosystems, spatial distribution and patterns of vegetation can remarkably reflect eco-environmental conditions in arid and semiarid areas, where groundwater plays a significant role. The impact of groundwater depth (GD) on the spatial variance in remote-sensing vegetation index is highlighted in this study over t...

Straightforward solutions have long been expected for the analysis of multiwell aquifer tests. In this paper, we derive series analytical solutions of steady-state groundwater flow in a rectangular-shaped aquifer with pumping/injection wells for both confined and unconfined conditions. Double Fourier Transform (DFT) technique is applied to deal wit...

Climate change has effects on hydrological change in multiple aspects, particularly in the headwaters of the Yellow River (HWYR), which is widely covered by climate-sensitive frozen ground. In this study, the annual runoff was partitioned into four runoff compositions: winter baseflow, snowmelt runoff, rainy season runoff, and recession flow. In ad...

Accurate estimation of evaporation (E0) over open water bodies in arid regions (e.g., lakes in the desert) is of great importance for local water resource management. Due to the ability to accurately determine sensible (H) and latent (LE) heat fluxes over scales of hundreds to thousands of meters, scintillometers are more and more appreciated. In t...

Streamline simulation in groundwater flow modeling is a time‐consuming process when a large number of streamlines are analyzed. We develop a parallelization method on Graphics processing units(GPUs) for the semi‐analytical particle tracking algorithm developed by Pollock(1988). Compute Unified Device Architecture (CUDA) was used to implement the pa...

Unconfined aquifers beneath piedmont pluvial fans are widely distributed in front of mountains and proper for water supply with pumping wells. However, the catchment zone and capture zones of a pumping well in such an unconfined aquifer is not well known. We develop a preliminary simplified model where groundwater flows between a segmental inflow b...

The groundwater divide within a plane has long been delineated as a water table ridge composed of the local top points of a water table. This definition has not been examined well for river basins. We developed a fundamental model of a two-dimensional unsaturated–saturated flow in a profile between two rivers. The exact groundwater divide can be id...

Estimating the lake level dynamics accurately on a daily or finer timescale is important for a better understanding of ecosystems, especially the lakes in Badain Jaran Desert, China. In this study, lake level dynamics of Sumu Barun Jaran are simulated and predicted on a 2-h timescale using the deep learning (DL) model, which is structured for the f...

GPU has been applied in groundwater flow simulation. In order to improve the performance of the GPU groundwater simulation further, this paper studied the method of parallelizing three-dimensional groundwater flow simulation on multiple GPUs. The most time-consuming part in the groundwater flow simulation, solving equations, is parallelized on mult...

To accelerate the streamline simulation and satisfy the real-time demands, in this paper, we proposed a method based on GPUs to parallelize the streamline simulation. CUDA architecture was used to implement the parallel algorithm on a single GPU and a multi-GPU computer. In our method, a grid is organized into a 2D array of blocks, and all threads...

Understanding the driving forces for alpine vegetation variations at different permafrost degrading stages is important when the Tibetan Plateau is experiencing climate warming. We applied the modified Frost Number model to simulate frozen ground distributions in the Tibetan Plateau and calculated the maximum thawing depth by the Stefan approach. W...

In a vadose zone the soil water content can change seasonally, driven by seasonal variations of meteorological factors. This dynamic behavior is depth-dependent, which controls the groundwater recharge from infiltration, and plays an essential role in the environments in arid and semi-arid regions. In particular, the depth-dependent seasonal variat...

A large number of lakes are distributed in the Badain Jaran Desert located at the northwest inland, China. Water evaporation is a key factor in the water cycle of lake and the entire desert. Based on the long-term meteorological and evaporative data from September 11, 2012 to March 26, 2013 and from May 8, 2013 to June 23, 2015 monitored by automat...

Groundwater sampled at the outlets of uncased flowing wells in a thick unconfined aquifer, which has undergone mixing, has been found to have hydrochemistry similar to deep groundwater in discharge areas. To identify the hydrodynamic causes, transient models of groundwater flow and age in a three-dimensional homogeneous unit basin with flowing well...

Hydrological responses to climate change are a widely concerning question, particularly for the source region of the Yellow River (SRYR), which is sensitive to climate change and is widely underlain by frozen ground. In considering climate change impacts on catchment properties, the traditional separation approach based on the Budyko framework was...

Though extensive researches were conducted in the source region of the Yellow River (SRYR) to analyse climate change influence on streamflow, however, few researches concentrate on streamflow of the sub-basin above the Huangheyan station in the SRYR (HSRYR) where a water retaining dam was built in the outlet in 1999. To improve the reservoir regula...

Accurate quantification of evaporation (E0) from open water is vital in arid regions for water resource management and planning, especially for lakes in the desert. The scintillometers are increasingly recognized by researchers for their ability to determine sensible (H) and latent heat fluxes (LE) accurately over distances of hundreds of meters to...

The occurrence of flowing wells in basins has been found to be closely related to the discharge area with an upward hydraulic gradient. Unfortunately, previous studies on upward gradient induced wellbore flow with equaling total inflow (Qin) in the deep and total outflow (Qout) in the shallow could not explain the occurrence of flowing wells. By re...

Accurate estimation of water level dynamics in lakes at daily or hourly time-scales is important for the ecosystem and formulation of water resources policies. In this study, lake level dynamics of Sumu Barun Jaran are simulated and predicted at hourly time scale using Deep Learning (DL) model. Two mature machine learning methods, namely Multiple L...

The Badain Jaran Desert (BJD) in China is a desert with impressive sand dunes and a groundwater situation that has attracted numerous researchers. This paper gives an overview of the mysteries of groundwater in the BJD that are exhibited as five key problems identified in previous studies. These problems relate to the origin of the groundwater, the...

The source region of the Yellow River (SRYR) provides 35 % of the rivers annual discharge but is very sensitive to the climate change. The change in discharge from the SRYR has been attributed to both climatic and anthropogenic forces, and previous estimates of the impact of human activities on the change in discharge have been higher than 50 % of...

Different formulas have been developed to estimate the mean annual evapotranspiration ratio (E/P) from the mean annual aridity index (Ep/P) based on the Budyko framework. A major challenge in using the Budyko framework for the interannual behaviors of a catchment is the missed storage. Here we develop a null-parameter formula of the storage-evapotr...

The Ordos Basin is one of the most intensively studied groundwater basins in China. The Ordos Plateau, located in the north part of the Ordos Basin, is ideal to study the pattern of regional groundwater circulation induced by water-table undulations due to the wavy topography and the relatively simple aquifer systems with macroscopically homogeneou...

Endorheic basins around the world are suffering from water and ecosystem crisis. To pursue sustainable development, quantifying the hydrological cycle is fundamentally important. However, knowledge gaps exist in how climate change and human activities influence the hydrological cycle in endorheic basins. We used an integrated eco-hydrological model...

Different formulas have been developed to estimate the mean annual evapotranspiration ratio (E/P) at catchment scale from the mean annual aridity index (Ep/P) based on the Budyko framework. A major challenge in using the Budyko framework for the inter-annual behaviors of a catchment is the missed storage in these formulas. Efforts have been contrib...

Soil saturation is thought to be an important control on plant zonation in intertidal wetlands, but quantitative studies linking saturation and plant zonation in real marsh systems are few. We conducted a combined field and modeling study to examine the potential links between groundwater flow and ecological zonation in a brackish marsh in the Yang...

To better understand the origin of water in the Badain Jaran Desert, China, water samples were collected from lakes, a spring and local unconfined aquifer for analyses of radiocarbon (14C), tritium (3H), stable hydrogen and oxygen isotope ratios (δ2H – δ18O), and d-excess values (=δ2H – 8δ18O). A series of evaporation experiments were also conducte...

Although it has been increasingly acknowledged that groundwater flow pattern is complicated in the three-dimensional (3-D) domain, two-dimensional (2-D) water table-induced flow models are still widely used to delineate basin-scale groundwater circulation. However, the validity of 2-D cross-sectional flow field induced by water table has been seldo...

Nested groundwater flow systems have been revealed in Tóth's theory as the structural property of basin-scale groundwater circulation but were only well known with two-dimensional (2D) profile models. The method of searching special streamlines across stagnation points for partitioning flow systems, which has been successfully applied in the 2D mod...

The Badain Jaran Desert was located at the northwest inland of China with drought and intensive evaporation. In stark contrast, there were dozens of permanent lakes inside the desert hinterland. Water recharge of the lakes in the Badain Jaran Desert has always been controversial. Based on water balance algorithm, this paper investigated the water r...

As an indispensable component of groundwater circulation, groundwater evapotranspiration rate (ETG) estimation using water table fluctuations is a hot research topic in the past decades. However, most existing methods for estimating ETG using either diurnal or seasonal water table fluctuations are based on the assumptions that groundwater recharge...

The region between Wuding River and Dosit River in the Ordos Plateau, China, is a typical arid to semi-arid zone in Northwest China. This region is covered by the Mu Us desert, whereas shallow groundwater exists in many places, which created a favorable condition for vegetation growing. Previous studies showed that the vegetation coverage in the Or...

To better understand the origin of water in the Badain Jaran Desert, China, water samples were collected from lakes, a spring and local unconfined aquifer for analyses of radiocarbon (¹⁴C) and tritium (³H), stable hydrogen and oxygen isotope ratios (δ²H, δ¹⁸O), and d-excess values (= δ²H – 8δ¹⁸O). A series of evaporation experiments were also condu...

The interactions between groundwater and surface water have been significantly affected by human activities in the semi-arid Hailiutu catchment, northwest China. Several methods were used to investigate the spatial and temporal interactions between groundwater and surface water. Isotopic and chemical analyses of water samples determined that ground...

Studies of isotope characteristics of lake water in a desert can provide important information on groundwater discharge and hydrologic partition of the lakes in the desert. This paper presents the investigation of ¹⁸O and ²H stable isotopes and radiogenic radium of different water endmembers in three representative lakes of Badain-E, Badain-W and S...

ABCD model is a climate hydrological model which has only 4 parameters, using precipitation and potential evapotranspiration as input and estimating evapotranspiration, runoff as well as the changes in soil water and groundwater storage. It is available in modeling catchment hydrology by month step or annual step. The ABCD model was applied in stud...

Groundwater-fed lakes are essential for the ecology in arid and semiarid regions. As a typical arid region, the Badain Jaran Desert (BJD) is famous in the world for the presence of a large number of groundwater-fed saline lakes among the mega dunes. Based on the up to date geological surveys and observations, this study analyzed the groundwater con...

The Budyko framework represents the general relationship between the evapotranspiration ratio (F) and the aridity index (φ) for the mean annual steady-state water balance at the catchment scale. It is interesting to investigate whether this standard F − φ space can also be applied to capture the shift of annual water balance in catchments with vary...

Quantification of groundwater recharge from precipitation in the huge sand dunes is an issue in accounting for regional water balance in the Badain Jaran Desert (BJD) where about 100 lakes exist between dunes. In this study, field observations were conducted on a sand dune near a large saline lake in the BJD to investigate soil water movement throu...

How lake systems are maintained and water is balanced in the lake areas in the Badain Jaran Desert (BJD), northeast of China have been debated for about a decade. In this study, continuous 222Rn measurement is used to quantify groundwater discharge into two representative fresh and brine water lakes in the desert using a steady-state mass-balance m...

Empirical equations have been formulated for the general relationship between the evapotranspiration ratio (F) and the aridity index (φ) in the Budyko framework. Though it is normally applied for mean annual behaviors, the Budyko hypothesis has been directly adopted to analyze the interannual change in water balance. However, there are reported cas...

Although it has been reported that flowing artesian wells could be topographically-controlled, there is no quantitative research on artesian flow conditions in unconfined aquifers. In this study, the water table, which has a lower amplitude than the land surface, is damped from the topography and used as the boundary condition to obtain the analyti...

The Badain Jaran Desert is the second largest desert of China with a total area of 49,200 km2. At least 72 perennial lakes are scattered throughout the desert, sustaining a unique desert-lake ecosystem. Groundwater of various origins was believed to play an essential role in maintaining those desert lakes, but hydrological measurements are lacking...

Despite prevailing dry conditions, groundwater-fed lakes are found among the earth's tallest sand dunes in the Badain Jaran Desert, China. Indirect evidence suggests that some lakes are shrinking. However, relatively few studies have been carried out to assess the regional groundwater conditions and the fate of the lakes due to the remoteness and s...

Supplementary information

Near- and off-shore fresh groundwater resources become increasingly important with the social and economic development in coastal areas. Although large scale (hundreds of km) submarine groundwater discharge (SGD) to the ocean has been shown to be of the same magnitude order as river discharge, submarine fresh groundwater discharge (SFGD) with magni...

The exchange rate between seawater and groundwater in a tidal flat was investigated at Laizhou Bay, China, where there are large-scale seepage faces with horizontal extension of several hundred meters developed during low tides. Taking into account the effects of seepage face and density, a simple and efficient method for estimating seawater–ground...

位于阿拉善高原的巴丹吉林沙漠分布有大量盐湖.为揭示盐湖分层特征以及地下水对盐湖水体的影响,选取沙漠腹地的第二大盐湖——苏木巴润吉林,对9月份湖水的温度和电导率剖面进行了观测.结果表明,尽管所测盐湖宽深比大于90,还是存在温跃层.温跃层的矿化度(TDS)为60~160 g/L,靠近湖底的水体存在TDS低值异常区,形成化跃层,推测为地下淡水集中排泄所致.这种湖底泉在其它较浅的盐湖水体中也存在,说明深、浅层地下水对盐湖水分及盐分都有贡献.温跃层水温随深度的变化近似符合静止水体的热传导规律,并没有受到地下水排泄热量的显著影响.研究区盐湖跃层的季节性变化还有待进一步研究.A number of salt lakes exist in the Badain Jaran Desert that locat...

The theory of regional groundwater flow is critical for explaining heat transport by moving groundwater in basins. Domenico and Palciauskas’s (1973) pioneering study on convective heat transport in a simple basin assumed that convection has a small influence on redistributing groundwater temperature. Moreover, there has been no research focused on...

Analytical studies on release/capture zones are often limited to a uniform background groundwater flow. In fact, for basin-scale problems, the undulating water table would lead to the development of hierarchically nested flow systems, which are more complex than a uniform flow. Under the premise that the water table is a replica of undulating topog...