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Water resources variability and availability in a basin affect river flows and sustain river ecosystems. Climate change and human activities disrupt runoff sequences, causing water environmental issues like river channel interruptions. Therefore, determining ecological flow in changing environments is challenging in hydrological research. Based on an analysis of long-term changes in hydrological and meteorological variables and interruption conditions in the semi-arid Liu River Basin (LRB), this study summarizes the controlling factors of river interruption at different temporal and spatial scales and proposes a framework to determine ecological flow under changing environments. Hydrological model and the monthly optimal probability distribution were used to determine the optimal ecological runoff of LRB. The results showed that from 1956 to 2017, precipitation and potential evapotranspiration in the basin showed no significant decreasing trend, but the streamflow significantly decreased, and the downstream interruption worsened, with an average annual interruption duration of 194 days at Xinmin Station from 1988 to 2017. The controlling factors of river interruption are as follows: (1) soil and water conservation measures in the upstream significantly reduce the runoff capacity; (2) the operation mode of the controlling reservoir in the middle reaches changes from "all-year discharge" to "winter storage and spring release" to "combined storage and supply," severing the hydraulic connection between upstream and downstream; and (3) siltation in the downstream river channel coupled with over-extraction of groundwater increases the seepage capacity of the river. The monthly ecological flow of Naodehai Reservoir was determined by considering the monthly seepage losses after reconstructing the natural runoff using the SWAT model and determining the optimal probability distribution function for monthly runoff. The findings are important for downstream LRB ecological restoration and for determining the ecological flow of other river basins in changing environments. [ABSTRACT FROM AUTHOR]

The Jinsha River basin (JRB), known as China's largest hydropower base, has been facing a surge in hydrological drought occurrences in the past several years. This study used the drought index model and soil and water assessment tool (SWAT) hydrological model to uncover the linkages between meteorological and hydrological drought using long-term datasets in the JRB. The results revealed that: (1) Over the past six decades, the JRB has experienced recurrent meteorological droughts, with the upper reaches being the most affected, accounting for a frequency of 17.5%. However, the frequency of drought in the middle and lower reaches has shown a marked increase in the last 15 years. (2) The frequency of hydrological drought in the JRB has been on the rise over the past six decades, with a particularly notable increase observed in the last two decades. Furthermore, a noticeable upward trend has been observed in the duration of these hydrological droughts. (3) The propagation durations from meteorological drought to hydrological drought exhibited noticeable seasonal differences in the JRB. The transmission duration during the flood season was shorter, whereas in the dry season, it was more protracted. Additionally, the connection between meteorological drought and hydrological drought demonstrates a weakening trend. The findings of this study hold significant implications for crafting an efficient reservoir dispatching strategy to safeguard the water security of the JRB. [ABSTRACT FROM AUTHOR]

Water quality parameters are key indicators of quality of water and can indicate the algal biomass and eutrophication in lakes. Therefore, this study spectrally inverted and evaluated the water quality of the Poyang Lake in China by analysing the differences between the measured water quality parameters and the observed image spectra of Sentinel‐2 remote sensing. This analysis was done using statistical regression models (SRMs) and various machine learning models (e.g., support vector machine [SVM] and random forest [RF]). The following major conclusions were drawn: (1) nutrients accumulated more in summer (June–August) than in winter (December–February). For example, in local areas of the main river, total nitrogen (TN) concentration reached 3.4 mg/L in summer of 2016, whereas total phosphorus (TP) concentrations were below 0.052 mg/L in winters of 2016 and 2017. (2) The three models, SRM, RF and SVM, achieved good results in the inversions of Secchi depth and permanganate index. However, differences were noted in the inversions of other parameters. For example, the goodness‐of‐fit (r2) between the inversion and measured values of TN concentration from RF was 0.81, while that from SR was 0.73. (3) The spatial distribution patterns of the water quality parameters showed differences. The ammoniacal nitrogen concentration was higher in the central region than that in the western region of the lake, whereas TP concentration was higher at the shoreline of the lake at 0.07 mg/L on 2 April 2017 but was relatively low in the main channel. [ABSTRACT FROM AUTHOR]

Drought is one of the most frequent and devastating natural disasters. Based on future climate scenarios and land use/land cover (LULC) patterns, the copula framework was employed to calculate the probabilities of meteorological and hydrological drought risks for the next 30 years (2021–2050) in the Wanquan River Basin, meanwhile, the relationship between hydrological and meteorological droughts was revealed by correlation analysis and cross-wavelet transform (XWT). The results are as follows: (1) In the next 30 years, the risk of intra-seasonal meteorological drought (short-term drought) in the WRB is high at a probability of 40–70%, while the risk of inter-seasonal meteorological drought is relatively small at a probability of close to 30%; (2) compared with meteorological drought, the risk of intra-seasonal hydrological drought is small, but the probability of inter-seasonal hydrological drought (medium- or long-term drought) is 30–50%, and the risk of hydrological drought in the upstream is greater than that in the downstream; (3) the future meteorological and hydrological droughts in the WRB are significantly and positively correlated, and that hydrological drought lags behind meteorological drought. [ABSTRACT FROM AUTHOR]

Modeling methodologies capable of coping with changing catchment conditions are becoming more important and are critical to ensure credible model predictions because the hydrologic process of the catchment is inevitably affected by climate change and human activities. A recently developed hydrological modeling framework that treats model parameters to be time-variant by building functions based on identified catchment properties is applied to the Upper Ganjiang River Basin in China experienced soil and water conservation constructions. The efficacy of the time-variant parameter method is investigated, and we further explore the impacts of model structure on hydrological modeling through this method. The approach is tested using two conceptual monthly water balance models, i.e., the ab model derived from the abcd model, and a two-parameter monthly water balance model (TWBM), which have the same model inputs and outputs, number of parameters and state variables. Results of the case study show that through the comparative analysis with the constant parameter models, both time-variant parameter models provide improved runoff simulations, especially for low and high flows. Moreover, the time-variant parameter method brings relatively larger runoff improvements for the TWBM model. For the actual evapotranspiration simulations, the ab model can yield improvements by treating parameter b (i.e., upper soil zone water holding capacity) to be time-variant, whereas the time-variant parameter method shows no efficacy in that for the TWBM model. The results demonstrate that the choice of hydrological model plays an important role in modeling performance of the time-variant parameter framework under a changing environment. Modification of the evapotranspiration calculation module for the TWBM model could be considered as further study to investigate the potential model improvement that compared with only time-variant parameters. This study can provide beneficial reference to comprehensively understand the impacts of changing environment on catchment hydrological modeling and thus improve the regional strategy for future water resource management. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Extensive environmental changes increase the complex uncertainty surrounding water allocation systems, and irrational water allocation further exacerbates competition among users, posing formidable challenges to achieving dynamic and sustainable water resource management in inter-basin water diversion (IBWD) projects. This study established a dynamic multi-objective water allocation framework to address environmental change, uncertainty of water systems, and coordination between water allocation and deficit risk. The proposed framework focuses on water allocation as a continuous, multi-period decision-making process and considers reasonable water allocation from the individual to the overall multidimensionality. The feasibility and practicality of the framework were verified by long-term water allocation planning of the Hanjiang-to-Weihe IBWD in Shaanxi Province, China. The framework integrates the Soil and Water Assessment Tool model, three classical scenarios of the Coupled Model Intercomparison Project Phase 6, and optimization models to realize future sustainable water allocation optimal planning. The study found that the framework enables sustainable water allocation management and provides decisions for decision-makers under different water deficit conditions. Global optimal water allocation and the maximization of system benefits were achieved using multi-objective dynamic modeling. The average satisfaction level exceeded 0.9, and the Gini coefficient was below 0.05, both of which have a synergistic effect, with the former enhancing satisfaction within each subarea, and the latter ensuring equity among the subareas. The proposed framework aims to manage water resources of IBWD sustainably and provide optimal water allocation schemes to decision-makers under changing environments, which will alleviate water scarcity and interregional competition to promote regional sustainable development. [Display omitted] • Environmental changes exacerbate uncertainty in water allocation system. • Combining predictive and optimization models for optimal water allocation. • Developing a framework for water allocation through multiobjective dynamic modeling. • Global optimal water allocation and maximized system benefits have been achieved. • Contribute to the sustainable management of water allocation. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To explore the mechanism of changes in the hydrologic cycle under the changing environment in eastern coastal areas of China,based on intensive observations from the hydrological station network and construction of experimental watersheds,we analyzed the distribution and responses of hydrological elements in areas of different land use and urbanization levels. The research results are as follows:① The spatial distribution of extreme rainfall exhibits differences,reaching 50 mm,and is mainly affected by the micro-topography and wind direction of the basin. ② For the runoff response for two basins with different urbanization levels,the flood response time,water level increase,and water level increase per unit rainfall of the highly urbanized basin are higher than those of the low urbanization basin,which is mainly affected by the size of the watershed and degree of urbanization. ③ Forest land plays a critical role in water conservation,and the decreasing process of soil moisture under forest land is slow,whereas the process in urban and cultivated land is faster;the average soil moisture lag times in 10 cm,20 cm,and 40 cm soil layers are 0-0.25 h,0.25-0.75 h,and 0.5-0.75 h,respectively,while the soil moisture response times for deep soil layers (60 cm and 80 cm) are more complex because of the influence of preferential flow. ④ The peak groundwater occurrence time has a hysteresis relationship with rainfall,and the lag time is 6.5-12 h. [ABSTRACT FROM AUTHOR]

Agricultural water scarcity is a global problem and effective management of limited water resources for irrigation to meet socioeconomic demands for sustainable development is a huge challenge. A stochastic multi-objective non-linear programming (SMONLP) model is developed for the identification of sound irrigation water allocation schemes. The SMONLP model improves upon previous methods by tackling contradictions of society-economy-resources as well as reflecting uncertainty expressed as probability distributions in an agricultural irrigation system. The SMONLP model permits in-depth analyses of various water allocation policies that are associated with different levels of water supply and climate change. The developed SMONLP model is applied to optimal irrigation allocation in a semi-arid river basin in China. Results reveal that the model coordinates the regulation of interactions of society-economy-resources by balancing the targets of water productivity, allocation equity, profit, economic benefit risk, blue water utilization, and leakage loss. Moreover, surface water availability associated with different violation risk probabilities can lead to the changes in comprehensive benefit of society-economy-resources and irrigation shortages. Nearly each of the 17 irrigation regions suffers from water deficit, because water is insufficient to satisfy the requirement of crops, however, the degree of water shortage is gradually weakened when flow level ranges from low to high. The coordination degree is also used to evaluate the sustainability of water allocation and the results of comparison show that the irrigation water allocation under RCP 4.5 presents lower coordination of society-economy-resources which are mainly attributed to the aggravated contradiction between water supply and demand. A real world study demonstrates the practicability of the developed model, allowing the river basin authorities to determine irrigation water allocation strategies in a changing environment, thus promoting sustainable development of agricultural irrigation systems. • A stochastic multi-objective model is presented for sustainable irrigation. • Mutual contradictions of society, economy, and resources are coordinated. • Effects of uncertainty and climate change on irrigation water allocation are evaluated. • Sustainability of the studied irrigation system is evaluated. • Various managerial insights of irrigation allocation are offered. [ABSTRACT FROM AUTHOR]

Due to changing environments, the conflict between water supply and demand in arid northwest China is becoming increasingly prominent, resulting in the water security challenges and the need for risk management. Therefore, this study aimed at developing an adaptive management approach for the compound systems of water ecology and socioeconomics in the Aksu River Basin (ARB), a typical northwest arid watershed in China. This strategy aimed to reduce risk based on an adjusted water resource management system with the stringent controls (i.e., total water consumption, water use efficiency, and minimum ecological water satisfaction rate controls 'three red lines'). The main findings are as follows: (1) Although the water resource system in the ARB is currently at low risk state, it could be subjected to higher risk levels in future scenarios. (2) An adjusted "three red lines" policy should be utilized to ensure adaptive management of risk in the water resource system. The corresponding coefficients for each "red line" was 8.37, 10.78, and 0.609, respectively. (3) Following a nonlinear multi-objective management, the vulnerability and risk decreased significantly, by −100% and −50%, respectively, whereas the resilience of the water resource system increased significantly, up to 330%. Therefore, adaptive water resource management is vital in reducing water resource risk, and is important for understanding the status of regional water resource systems and solving water security problems in a changing environment. • The risk of water resources system in the Aksu River basin is getting higher and higher. • The existence of a set of undetermined coefficients makes the multi-objective management equations set up. • Water resource risk management can well reduce the risk in the Aksu River basin. • The adaptive management is of great significance for the regional sustainable development. [ABSTRACT FROM AUTHOR]

Owing to its combination of superior natural conditions and abundant resources, the Pearl River Delta (PRD), China, is densely populated, with concentrated industry and rapid development. The PRD is also one of the most threatened estuaries in the world, as it has been exposed to an increasing series of crises related to water resources. Water conflict, water pollution, and saltwater intrusion have all increased dramatically in the past few decades, which pose a threat to regional water security and impose constraints on regional development. The goal of this paper is to analyze the causes and impacts of some of the water resource crises faced by estuaries under dramatically changing environments, based on studies in the PRD. The PRD is centered around the Pearl River Estuary (PRE) and is the second most economically active district in China. Rapid economic development and a population boom have resulted in an average annual growth rate of 1.43% in water resource demand, which has further accelerated water pollution by a substantial growth in sewage discharge. Water pollution results in the impairment of the ecological functions of the water, and the standard rate of water function areas in the PRD remains under 50%. Large-scale and uneven sand excavations not only decreased the river discharge from upstream but also allowed more tidal prisms to enter, which triggered severe saltwater intrusion. Meanwhile, sea-level rise and changing wind patterns also contribute to increasingly severe saltwater intrusion, which was characterized by gradual increases in salinity, as well as more prolonged periods of higher salinity that exceeds acceptable thresholds occurring earlier in the year. This study is intended to bring attention to these challenging issues and provide some of the information needed to advance research into sustainability assessment of the water resources. [ABSTRACT FROM AUTHOR]

As the two largest rivers in China, the Yangtze and Yellow Rivers are of great importance for water cycle and hydrological processes over the country, which have been significantly affected by climate change. In this study, by assessing the suitability of multiple GCMs (General Circulation Models) recommended by IPCC (Intergovernmental Panel on Climate Change), SDSM (Statistical Downscaling Model) and ASD (Automated Statistical Downscaling) were used to generate future climate change scenarios, which were used to drive VIC (Variable Infiltration Capacity) and SWAT (Soil and Water Assessment Tool) models to quantify climate change impacts in the Yangtze River Delta region and upper reaches of the Yellow River basin, respectively. Results showed that suitability assessment method adopted in this study coupled with statistical downscaling could effectively reduce uncertainties of GCMs. Compared with the baseline period (1961-1990), projected annual runoff in future periods (2046-2065 and 2081-2100) would decreased by 9.5% and 3% in the Yangtze River Delta region. While annual runoff in the upper Yellow River basin during future two periods would decrease by 16.9% and 22.2%. The results are of great significance to future water resources management and sustainable development under climate change in major river basins of China. [ABSTRACT FROM AUTHOR]

Irrigation is an important measure for increasing grain production. Improving water use efficiency in agriculture is expected to play a very important role in ensuring food and water security in China, since there is a serious problem between food supply and limited water resources in China. The present state and future trend of water and food security in China were analyzed, while the importance of irrigation in ensuring China food security was highlighted based on the analysis of the evolution of irrigation water productivity in recent 60 years and its relationships with changes of crop yield, cropping pattern, fertilization and irrigation water use. Research progresses and practical application on high-efficient agricultural water use in China were introduced, and two successful cases of improving agricultural water productivity in China were presented, one was to improve crop water use efficiency by the novel irrigation method based on crop physiological responses, and the other was to improve the regional water productivity by the integrative methods in the Shiyang River Basin of Northwest China. The major research areas needed to focus on in the future were discussed, which include responses of crop water demand to changing environment and associated spatio-temporal optimization of water allocation, multi-processes hydrologic cycle of irrigated land under strong influences of human activities, integrated measures for improving multi-scale agricultural water use efficiency, and interactions between grain production, water resources and ecological system and its sustainability analysis in a systematic way. [ABSTRACT FROM AUTHOR]

Under the combined impacts of climate change and human activities, a series of water issues, such as water shortages, have arisen all over the world. According to current studies in Science and Nature, water security has become a frontier critical topic. Water supply security (WSS), which is the state of water resources and their capacity and their capacity to meet the demand of water users by water supply systems, is an important part of water security. Currently, WSS is affected by the amount of water resources, water supply projects, water quality and water management. Water shortages have also led to water supply insecurity. WSS is now evaluated based on the balance of the supply and demand under a single water resources condition without considering the dynamics of the varying conditions of water resources each year. This paper developed an optimal allocation model for water resources that can realize the optimal allocation of regional water resources and comprehensively evaluate WSS. The objective of this model is to minimize the duration of water shortages in the long term, as characterized by the Water Supply Security Index (WSSI), which is the assessment value of WSS, a larger WSSI value indicates better results. In addition, the simulation results of the model can determine the change process and dynamic evolution of the WSS. Quanzhou, a city in China with serious water shortage problems, was selected as a case study. The allocation results of the current year and target year of planning demonstrated that the level of regional comprehensive WSS was significantly influenced by the capacity of water supply projects and the conditions of the natural water resources. The varying conditions of the water resources allocation results in the same year demonstrated that the allocation results and WSSI were significantly affected by reductions in precipitation, decreases in the water yield coefficient, and changes in the underlying surface. [ABSTRACT FROM AUTHOR]

This paper focused on the development of a framework for collective water resources management in China to meet the change of drought and flood. Based on the observational data of drought and flood from 1950 to 2009 and the precipitation from 1961 to 2010, using the Standardized Precipitation Index (SPI) method, the evolutionary characteristic of drought and flood was analyzed. The results showed that drought and flood occurred frequently, simultaneous occurrences of drought and flood and the rapid shift between the two were increasing. The framework for collective strategies responding to drought and flood under this ever-changing environment was presented. A series of potential mitigation, prevention, and adaptation strategies were discussed. These included both planning and implementation side strategies. In regard to planning, the strategies for dealing with drought and flood should be shifted from crisis management to collective management, unifying normal and emergency management. Combination risk zoning of drought and flood should be conducted and collective emergency planning should be formulated. Moreover, the regulation capability of water conservancy projects group should be optimized to the highest possible level. In regard to implementation, based on the water resources collective management, rational water allocation for both normal and extreme value processes should be implemented. The water conservancy project groups for the extreme value process should work together, and the flood limit water level of reservoirs should be controlled dynamically. [ABSTRACT FROM AUTHOR]

• An adaptive complementary operating rule with time-varying parameters was proposed. • State transition and observation from the same period of previous year are suitable. • The proposed method is still effective for nonstationary reservoir inflow and solar radiation. The complementary operating rules of hydro-photovoltaic (PV) hybrid power plants have been explored fully to operate reservoirs for complementing the PV output. However, prevailing operating rules were constant, which is incapable to be dynamically updated based on new observations. To address this issue, adaptive complementary operating rules were developed to deal with the future uncertainties of reservoir inflow and solar radiation using ensemble Kalman filter (EnKF). First, a long-term complementary optimization model was developed to derive the initial parameters of linear operating rules. Then, the optimal decisions under historical condition were used as the observation. Finally, six assimilation schemes were proposed, according to the two state transition equations (the same period of the previous year, the previous period) and three observations (the same period of the previous year, the previous period and their joint). China's Longyangxia hydro-PV hybrid power plant was chosen as a case study. Results show that (1) the two state transition equations have comparative effects on operation results, (2) the choice of observation plays a decisive role. The assimilation scheme, in which the optimal operation decision of the same period in previous year is as observation, outperforms the stationary operating rules. Specifically, the total power generation and guaranteed rate are improved by 7.14% and 5.33%, respectively, (3) the deriving framework works effectively under the synthetic nonstationary reservoir inflow and solar radiation, and ensures the stability and security of energy system in the changing environment. [ABSTRACT FROM AUTHOR]

The changing environment has led to significant changes in the supply and demand of runoff, directly affecting the benefits of the multi-reservoir systems. Adaptive operation and quantitative control can hedge against the negative effects of changing environment for multi-reservoir systems, while studies related to the general theory and methods or models of such operations are inadequate. In this context, an adaptive control framework for multi-reservoir systems is proposed from a supply and demand perspective. Under this framework, a multi-objective optimal operation model is first established for adaptive control analysis, and the adaptive control measures based on supply-side, demand-side, and supply-demand linkage perspectives are designed. The effects of different control measures are further evaluated through scenario simulation analysis to recommend control schemes, using a multi-reservoir system in the Upper Yangtze River Basin of China as an example. The results suggest that the supply-demand linkage is an effective method to minimize the negative effects of changing environment on multi-reservoir systems, such as changes in runoff, increasing demands in water supply, population growth and socioeconomic development, etc. The proposed framework is shown to be feasible and effective in developing control measures for multi-reservoir systems to adapt to changing environments, which can provide a theoretical basis for the management of multi-reservoir systems under changing environments. • A framework for adaptive control of multi-reservoir systems is developed. • An optimal operation model is established for adaptive control analysis. • Adaptive control measures are designed under the framework. • The effects of control measures are evaluated through scenario simulation analysis. • A case study is conducted based on the proposed framework using real-world data. [ABSTRACT FROM AUTHOR]

Irrigated agriculture is the dominant user of world's fresh water which feeds the world's growing population. Conflicts between stakeholders; incompatibility of economic, social, and environmental development; and uncertainties in water supply and demand restrict the sustainable development of irrigated agriculture. This study developed a multi-scale multi-objective programming model for simultaneous optimal allocation of irrigation water and cropland to balance conflicts between farmers' income and sustainable development of irrigation districts (reflected in economic, social, and environmental aspects). Consideration of the joint uncertainties of water supply and demand helps provide practical and indicative schemes for agricultural water and land allocation. The developed model was applied to a real case study in an irrigation district in northeast China. Farmers' income, net economic benefit, resources allocation equity, and global warming potential were coordinated by optimally allocating limited water and cropland resources to different crops in different subareas under different combinational scenarios of water supply and demand. The performance of the model was evaluated, based on the concept of "adaptability" which can help realize the degree of ability of the irrigated agricultural system to adapt to changing environment. The developed model can help plan irrigation water and cropland resources in a sustainable way, and can be a reference for similar irrigation systems worldwide. • A multi-scale model is developed for simultaneous allocation of irrigation water and cropland. • Conflicts between farmers' income and sustainable development of irrigation districts are balanced. • Trade-off between social, economic, environmental, and resources aspects can be tackled. • Joint uncertainties of water supply and demand are considered. • System adaptation to irrigation water and cropland re-allocation is assessed. [ABSTRACT FROM AUTHOR]

Climate change and anthropogenic activities do collectively lead to an alteration of the flow regime, posing a great influence upon the structure and persistence of native biotic communities within river ecosystems. The range of variability approach (RVA) method is commonly used to evaluate the flow regime alteration. However, it was reported to underestimate the degree of flow regime potentially. In this study, two new assessment methods/metrics for evaluating the process behaviors of the flow regime are developed based on Euclidean distance and dynamic time warping (DTW) distance. They are then integrated with the metric of RVA, generating two composite metrics that represent both frequency and process changes of the flow regime. The new methods/metrics were applied to identify the flow regime alteration in a typical basin in the middle reaches of the Yellow River, China. The results show that the composite metrics consistently reveal a high alteration degree of flow regime in the basin. The decreased biological integrity of fish demonstrates the reasonability of the high-level overall alteration to some degree. The updated methods enable more scientific evaluation for the complex hydrologic alteration under a changing environment. [ABSTRACT FROM AUTHOR]

With a shifting climate pattern and enhancement of human activities, coastal areas are exposed to threats of groundwater environmental issues. This work takes the eastern coast of Laizhou Bay as a research area to study the response of a coastal groundwater system to natural and human impacts with a combination of statistical, hydrogeochemical, and fuzzy classification methods. First, the groundwater level dynamics from 1980 to 2017 were analyzed. The average annual groundwater level dropped 13.16 m with a descent rate of 0.379 m/a. The main external environmental factors that affected the groundwater level were extracted, including natural factors (rainfall and temperature), as well as human activities (irrigated area, water-saving irrigated area, sown area of high-water-consumption crops, etc.). Back-propagation artificial neural network was used to model the response of groundwater level to the above driving factors, and sensitivity analysis was conducted to measure the extent of impact of these factors on groundwater level. The results verified that human factors including irrigated area and water-saving irrigated area were the most important influencing factors on groundwater level dynamics, followed by annual precipitation. Further, groundwater samples were collected over the study area to analyze the groundwater hydrogeochemical signatures. With the hydrochemical diagrams and ion ratios, the formation of groundwater, the sources of groundwater components, and the main hydrogeochemical processes controlling the groundwater evolution were discussed to understand the natural background of groundwater environment. The fuzzy C-means clustering method was adopted to classify the groundwater samples into four clusters based on their hydrochemical characteristics to reveal the spatial variation of groundwater quality in the research area. Each cluster was spatially continuous, and there were great differences in groundwater hydrochemical and pollution characteristics between different clusters. The natural and human factors resulted in this difference were discussed based on the natural background of the groundwater environment, and the types and intensity of human activity.