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The pulp and paper sector has been a significant source of water pollution in China for many years. The Chinese government has made great efforts on water pollution control for the pulp and paper sector. While actively participating in various international treaties and conventions related to environmental management and pollution control in this sector, China has created a comprehensive environmental management framework, including several environmental policies, regulations and standards. This study reviews the current environmental framework for the management and control of water pollutants generated by the pulp and paper industry in China, with reference to relevant experiences. Apart from assessing the achievements that China has made, this study proposes some recommendations to further enhance water pollution control capacity and facilitate effective legal enforcement. Approaches such as improvements to environmental standards and permit systems, technical upgrading, cleaner production strategy, environmental monitoring improvements, integration of financing channels for environmental improvement, and enhancement of social responsibilities of enterprises are addressed. [ABSTRACT FROM AUTHOR]

Due to the influence of the groundwater system, mountain rock layers, climate rainfall, and tunnel length and depth, underground tunnels (UT) are prone to water inrush (WI) disasters, thus leading to delays and obstacles in construction projects. This paper takes the Yonglian Tunnel as the research objective and explores the water and mud inrush disasters that occurred from July to August 2012. The Yonglian Tunnel is a control project of the Jilian Expressway in Jiangxi Province. This paper aims to study and analyze the WI disaster management of the UT using artificial intelligence technology, and to deepen the understanding of its causes. It will affect the factors, hazards, and related disaster management engineering methods of the UT WI disaster. By establishing a back-propagation neural network model and a radial basis function neural network model, the risk of WI disasters in tunnels, the degree of harm caused by WI, and the ability to control them were predicted and analyzed, and the stability and error values of the models were compared. [ABSTRACT FROM AUTHOR]

Based on whether the 'One River, One Policy' is implemented or not, this paper used the questionnaire data of village (community) river chiefs in nine districts and counties under the jurisdiction of Jinhua City, Zhejiang Province, and used the Difference-In-Differences Model to carry out an empirical analysis. The findings are threefold. Firstly, the 'One River, One Policy' implemented by primary river chiefs can improve the water quality of the river reaches in their charge. Secondly, annual river patrol times and public support can improve the water quality of the river reaches in charge of primary river chiefs. Thirdly, the River Chief System (RCS) can promote the treatment of river pollution under 'Responsibility Contracting', but for primary river chiefs, there is still a suspicion of whitewash pollution control behavior, so whether to establish a longterm mechanism of the RCS is still uncertain. The purpose of this paper is to provide empirical support and decision-making reference for constructing the positive incentive mechanism of the behavior of primary river chiefs in the reconstruction of the RCS, which has important practical significance for effectively improving the RCS and comprehensively promoting the Chinese experiences of river pollution control. [ABSTRACT FROM AUTHOR]

This paper constructs a green development efficiency index framework of water-energy-food in China, and uses the Super-EBM model to measure it more accurately and scientifically. The existing studies on water-energy-food efficiency lack the analysis of regional differential decomposition and spatial state transition. In this paper, two kinds of models are used for complementary analysis. One is kernel density map, Dagum spatial Gini coefficient decomposition and traditional Markov chain, which does not contain spatial factors. The other is the global Moran index, spatial Markov chain and spatial spillover effect, including spatial factors. The spatio-temporal dynamic evolution of the green development efficiency of water-energy-food (GWEF) in China is compared from the perspective of national, regional and provincial dimensions. The conclusion is more scientific and comprehensive, which is conducive to the green collaborative development among water-energy-food, economy and environment in China. The study found that GWEF had a lot of room for improvement. The overall spatial difference was mainly derived from the regional difference. GWEF had a significant positive spatial autocorrelation. The development of GWEF maintained the convergence characteristics of clubs. The spatial spillover effect of the main influencing factors was studied. [ABSTRACT FROM AUTHOR]

Regional water conservation is the key to maintain water supply. Based on the data of 2000, 2010 and 2020, this paper takes Jingyu County in the Changbai Mountain as the study area. By land use conversion matrix, geostatistical analysis, InVEST model and scenario analysis, this paper aims to find out the variation of water conservation and the its related influencing factors in Changbai Mountain region. From 2000 to 2020, forest and cultivated land decreased, while grassland and developed land increased. The water conservation increased from 2.94 x 108 m³ to 4.83 x 108 m³, with a total increase of 64.29%. Forest has the highest average water conservation, followed by grassland, cultivated land and developed land. Climatic factors were important to 91.92% of the study area, whereas 6.22% of it was influenced by land use. When forest decrease in some areas, the main control factor of 48.71% of the area shifted into land use, that could lead to a sharp decrease in water conservation. Climate determines the overall spatial pattern of water conservation; land use determines the local characteristics by controlling runoff. The increase of water conservation is beneficial to improve the reserves and development potential of mineral water. [ABSTRACT FROM AUTHOR]

With large-scale industrial parks developing, concern regarding high evaporation and its spillover impacts on water environment and water ecology has grown significantly in recent years. However, it is hard for the traditional water audit to meet the needs of the collaborative management of water environment and water ecology based on evaporation (3E), which requires a multi-dimensional evaluation. The purpose of this paper is to accurately evaluate industrial parks' impact considering the water life-cycle. This paper proposes a systematic 3E water audit method that contains a logical framework and a comprehensive evaluation index system with five dimensions and 25 indexes, then applies it to a typical iron and steel industrial park in China. The results presented the 3E audit score of the Chengsteel IP as 89.91, suggesting comprehensive performance is good. The score and grade of every index, especially the quantity of water evaporation per ton of steel, were provided. This paper indicates that the new method developed can systematically evaluate the impact of industrial parks. In addition, our analysis highlights the different management strategies and practices that relieve the impacts of the whole water-use process on legal, eco-environmental, economic, social, and technical dimensions. [ABSTRACT FROM AUTHOR]

Urbanization has been the main driving force for China's economic growth in recent years; however, the highly concentrated urbanized lifestyle has brought many environmental problems to residents, the most urgent of which is urban stormwater management. Some countries have proposed plans for urban stormwater management, such as Low Impact Development (LID), Water Sensitive Urban Design (WSUD), and Sustainable Urban Drainage Systems (SUDS). As a country with relatively underdeveloped urban stormwater management, China's government proposed an ambitious urban stormwater management plan in 2014, called the Sponge City Programme, which means that a city is designed to act like a sponge, with good 'resilience' in adapting to environmental changes and coping with natural disasters. As of 2021, this programme has led to SCP projects in 30 pilot districts all over China, the Sponge City Programme construction impacts both urban development and residents' lives. However, there are risks and challenges associated with these projects. Using government research documents as a framework, this paper carefully reviews the progress of the Sponge City Programme in recent years and shows the main challenges faced by the Sponge City Programme in terms of connotation, investment, and technology. On this basis, the paper puts forward practical suggestions for the development of the Sponge City Programme and details potential opportunities of new technology, ideology, planning, and flexible investment. [ABSTRACT FROM AUTHOR]

The South-to-North Water Diversion project, as one of China’s strategic projects, plays an important role in China’s development. Sixty-two years after the project was conceived, the central route project began to supply water in 2014. Users along the route are both beneficiaries and project influencers. Their behavior characteristics in the project operation have become a topic worthy of study. In this paper, based on a questionnaire conducted among government departments, enterprises and residents and on stakeholder theory, under the theory model of Sustainable Supply Chain (SSC) around the Triple Bottom Line (TBL) including society, economy and environment, the ecological compensation, sewage treatment and reservoir operation management in Xichuan County were investigated and studied. A total of 289 answers were recovered. Through the survey, it is found that: stakeholders include 15 township governments in Xichuan County, water conservancy project supporting facilities construction companies, ecological industry companies, water supply companies and other enterprises, as well as agricultural growers, rural farmers and non-agricultural residents in Xichuan County. Government stakeholders pursue the development of the overall operation of the project, while enterprises and residents pursue the development of individual economy. Finally, this paper lists the relevant indexes, which provide the opportunity for behavior evolution analysis and sustainable research of the project. [ABSTRACT FROM AUTHOR]

A study on the risk of Cretaceous water inrush in the Ordos Basin in China is of great significance to the safe production and environmental protection of the western coal seam. This paper selects the following five key influencing factors for Cretaceous water inrush: the coal seam mining thickness, rock quality designation, distance between the top boundary of the waterconducting fracture zone and the bottom boundary of the Cretaceous system, the thickness of the Cretaceous aquifer, and the height of the water head. Furthermore, based on an analysis of geological and hydrogeological conditions of the Yingpanhao coal mine, the comprehensive weights of these factors were found using a fuzzy analytic hierarchy process and the entropy method (FAHP-EM) to be 0.27, 0.25, 0.22, 0.08, and 0.18, respectively. This paper describes the use of ArcGIS's spatial overlay analysis to create a risk assessment zoning map using these weightings. By comparing the evaluation results of the FAHP-EM and the water inrush coefficient method, it is shown that the FAHP-EM provides additional insight in assessing the risk of coal seam roof water inrush. The research results of this paper provide a theoretical basis for coal mining safety in western China to assess water inrush. [ABSTRACT FROM AUTHOR]

Comprehensive assessment of river health is challenging due to the diversity of rivers, the complexity of their ecosystem and functional service. This paper updates the river health assessment indicator system, weight, and assignment criteria in China by reviewing and examining the peer-reviewed literature. We propose an indicator system, weight, and criteria, validated by nine case studies and able to assess the country-scale river health. Our analysis shows that the rule layer of indicator system includes hydrology, water quality, aquatic organism, physical habitats, and functional service; its corresponding weights are set to 0.15, 0.21, 0.18, 0.22, and 0.24, respectively. The ten most representative indicators are selected that incorporates the indicator layer with their corresponding weights. The evaluation based on case studies shows that in eight out of nine cases, our results are consistent with those obtained in previous studies. Therefore, the suggested index system, weight, and three-assessment criteria are well suited for the complex cases in China. This paper can serve as a reference for a river health assessment and present a comprehensive listing of assessment criteria. [ABSTRACT FROM AUTHOR]

Traditional flood simulations fail to properly consider the impact of soil infiltration in floodplain areas with high soil infiltration rates. Notably, ignoring soil infiltration will lead to considerable uncertainty in flood simulations. In this paper, a fully hydrodynamic model coupled with the Green-Ampt infiltration model was used. Taking a natural reach in northern China (HTH in this paper) as a case study, observed flood discharge data were used to analyze the influence of soil infiltration on flood propagation based on the flood propagation simulation results for various inflow conditions. The maximum difference of inundation area is about 25%. The results show that soil infiltration has little effect on the inundation area during the rising stage of a flood. In the late period of a flood, the inundation area considering the effect of infiltration is smaller than that without infiltration, and the smaller the peak coefficient is, the longer the flood duration is, the larger the impact of infiltration on the inundation area. When the peak shape coefficient is 0.42 and the flood duration is 44.4 h, the maximum difference of the inundation area is about 28%. The research results provide a reference for flood management and post-disaster rescue efforts. [ABSTRACT FROM AUTHOR]

Water allocation can be evaluated from various economic, environmental, food security, and climate aspects. This paper was conducted to develop an optimal water allocation strategy with an economic framework. Game theory has been used to determine the planning structure. A co-operative technique based on the core solution, Shepley value, and nucleolus solution has been incorporated into the decision-making system and the results of the proposed model have been calculated based on the long-term information of the downstream cropping pattern in the Zhanghe irrigation network, Hubei Province, China. Five components of rice planting including growth period, yield production, water consumption, selling price, and cultivated area have been evaluated to find the optimal scenarios. Results showed that the application of cooperative game theory can improve the economic index and water-saving potential in agriculture. Furthermore, the proposed simulation confirmed that the economic effects were important for understanding and planning for irrigation efficiency and water-saving potential. [ABSTRACT FROM AUTHOR]

When the requirements for water pressure and quantity of drinking water for residents and industrial buildings exceed the capacity of the urban water distribution system, a secondary water supply system (SWSS) is supplied to users by pipelines through storage, pressurization, and other facilities. In China, SWSS has been installed in 97% of residential buildings and the operation of SWSS is directly related to the water pressure and water quality of the users’ tap water. In this paper, the operation optimization objectives for the SWSS with storage facilities were proposed, and deep Q-learning network (DQN) was applied to optimize the control of SWSS. In this study, the pressure, the water age in the roof water tank, and the power consumption of the pumps were selected as the optimization objectives. The equation for the qualitative selection of the key hyperparameter (Gamma) was proposed and verified by the experiments in a community of City S in East China. The results indicated that with the decrease in the volume of the water tank, the larger Gamma value was recommended, and the more future conditions were considered. It is hoped that the result can be used as a reference in SWSS operation optimization. [ABSTRACT FROM AUTHOR]

High-precision water quality prediction plays a vital role in preventing and controlling river pollution. However, river water's highly nonlinear and complex spatio-temporal dependencies pose significant challenges to water quality prediction tasks. In order to capture the spatial and temporal characteristics of water quality data simultaneously, this paper combines deep learning algorithms for river water quality prediction in the river network area of Jiangnan Plain, China. A water quality prediction method based on graph convolutional network (GCN) and long short-term memory neural network (LSTM), namely spatio-temporal graph convolutional network model (ST-GCN), is proposed. Specifically, the spatio-temporal graph is constructed based on the spatio-temporal correlation between river stations, the spatial features in the river network are extracted using GCN, and the temporal correlation of water quality data is obtained by integrating LSTM. The model was evaluated using R2, MAE, and RMSE, and the experimental results were 0.977, 0.238, and 0.291, respectively. Compared with traditional water quality prediction models, the ST-GCN model has significantly improved prediction accuracy, better stability, and generalization ability. [ABSTRACT FROM AUTHOR]

At present, China's rural water resources are in short supply and the water pollution situation is severe. Family farms are an important part of China's agricultural modernization, and their development level is an important indicator to measure the degree of modernization of a country and a region. The application of agricultural Internet of Things technology in the field of agriculture is helpful for solving the problem of water shortage in family farms in water shortage areas. Based on questionnaire data, this paper used structural equation modeling (SEM) to study the relationship between family farm water financing willingness and behavior. The results showed that the standardization coefficients of Assumption 1, Assumption 2 and Assumption 3 were 0.332, 0.267 and 0.311, respectively. It can be seen that the water resource financing willingness of family farms was greatly affected by their water-saving technology ability, water management ability and government policy support. However, the standardization coefficient of Assumption 5 was 0.087. It can be seen that the water management capacity had no significant impact on the water resource financing behavior, and the water resource financing behavior of family farms was mainly affected by their water-saving technical capacity and government policy support. [ABSTRACT FROM AUTHOR]

The problem of soil and water loss on slope land has always been one of the key issues that people pay attention to. How to reasonably arrange tree species and planting methods can effectively improve the current situation of water loss and soil erosion. The Revised Universal Soil Loss Equation (RUSLE) model is a widely used soil erosion prediction model, but it does not consider the impact of tree height and crown size on soil erosion. In this paper, six experimental plots of soil and water conservation were carried out on the forest slope land in southern China. Six experimental plots were planted with different trees, and all kinds of data were collected for 3 years. On the basis of data analysis and machine learning methods, it is found that tree height and crown have a significant impact on soil erosion, but have no significant impact on runoff formation. With the growth of trees, the amount of soil loss in each plot gradually decreases. At the same time, an improved RUSLE model related to tree height and crown has been established, which has a high simulation effect (R2 of testing reaches 0.6775, R2 of all data reaches 0.5452). [ABSTRACT FROM AUTHOR]

Inter-basin water diversion reallocates water resources by changing their spatio-temporal distribution characteristics between basins. This can effectively relieve water supply and demand conflicts in regions with water resource reserves shortages. However, building inter-basin water diversion projects obviously reduces the inflow from upstream, leading to increasingly conspicuous conflicts between water diversion outside a basin and water utilization inside the basin. To relieve this conflict and explore the optimal scheme of water resource allocation across river basins, this paper chooses the Middle Route Project of the South-to-North Water Diversion Project on the Hanjiang River as a case study. A water supply scheduling model of Danjiangkou Reservoir is built using an integrated inter-basin diversion draw water reservoir regulation (IDR) model to balance multiple conflicting water demands. In the IDR model there are two types of objective sets: aggregate indicators and process matching degree functions. Moreover, six evaluation indexes are selected to analyze the water resource allocation effect of the optimal scheme. The simulation results indicate that the proposed IDR model in this paper is practicable and efficient for water resource allocation across river basins. [ABSTRACT FROM AUTHOR]

The evaluation of irrigation water efficiency plays an important role in the efficient use of agricultural water resources and the sustainable development of agriculture. In order to make the evaluation of irrigation water use efficiency indicators more comprehensive and scientific, this paper constructs a new optimal model of evaluation indicators. By combining the Driver-Pressure-State-Impact- Response (DPSIR) model with the Information Significance Difference (ISD) evaluation indicators model, a novel DPSIR-ISD evaluation indicators combination model was constructed. Ten riverside irrigation areas in the Sanjiang Plain of northeastern China were selected for analysis. The results show that the DPSIR-ISD model was used to reduce the number of indicators from 44 to 14; these 14 indicators reflected 91.88% of the original information. The DPSIR-ISD method proposed in this paper takes into account the completeness and simplicity of the indicators system, and is more in line with the actual situation in the field. These results can provide a simpler and more convenient system for optimizing indicators for the study of evaluation indicators used to analyze irrigation water use efficiency. [ABSTRACT FROM AUTHOR]

Modern mining within ecologically fragile areas is under enormous pressure from the ecological and geological environment. Using abandoned coal mines as underground water reservoirs is an effective idea for reducing eco-geological risks in mining districts. Accurate estimation of reservoir capacity is conducive to guiding the construction of an underground water reservoir. In this paper, estimation models of underground water storage capacity were established, which were divided into two kinds: horizontal mining district and inclined mining district. Furthermore, the minimum porosity of broken rock mass was analyzed based on laboratory experiments, and the fitted equation of minimum porosity was developed. A modern coal mine in northwest China was taken as an example, and the feasibility of the proposed model was verified by in-situ measurement. Finally, the effects of porosity of broken rock mass, water storage height and coal seam dip angle on water storage capacity were presented. The coal seam dip angle should be the principal consideration in choosing the site of an underground water reservoir. [ABSTRACT FROM AUTHOR]

The standard cuckoo search algorithm (SCSA) is an intelligent population optimization algorithm, which is also a heuristic search algorithm. The advantages of the SCSA (such as its convenient operation, heuristic searching, etc.) make it easy to find an optimal solution and maintain a wide searching range. However, the SCSA also has some drawbacks, such as long searching time, and the ease of falling on a local optimum. In order to solve the problems existing with SCSA, in this paper, an improved standard cuckoo search algorithm (ISCSA) was studied, which includes chaotic initialization and a Gaussian disturbance algorithm. As a case study, taking economic, social and ecological benefits as the objective function, multi-objective water resources optimal allocation models were constructed in Xianxiang Region, China. The ISCSA was applied to solve the water allocation models and a multi-objective optimal water supply scheme for Xinxiang region was obtained. Water resources optimal allocation schemes for the planning level year (2025) for 12 water supply sub-regions were predicted. A desirable eco-environment and other benefits were achieved using the studied methods. The results show that the ISCSA has obvious advantages in the solution of water resources optimal allocation and planning. [ABSTRACT FROM AUTHOR]

Mine water inrush is a major type of disaster in coal mine production in China. It causes heavy casualties and serious economic losses and threatens coal mine safety. To quickly and accurately identify mine water inrush source, according to the hydrochemical characteristics of different aquifers in the Donghuantuo mining area, this paper systematically analyzes the hydraulic connection of the aquifers in main coal mining areas before and after mining activities. Four types of hydrochemical data were collected: No. 5 coal seam roof water, No. 8 coal seam roof water, No. 122 coal seam floor water, and No. 1214 coal seam aquifer water in the Donghuantuo mining area. In addition, based on the hydrochemical data, the parameter selection of LightGBM was optimized by Particle Swarm Optimization (PSO) and constructed the PSOLightGBM water inrush source identification model. The recognition accuracy of PSO-LightGBM model was compared with LightGBM model, classification regression tree (CART) model, and random forest (RF) model. The results showed that coal mining activities would have a significant impact on the water quality characteristics of the roof sandstone fissure water of No. 5 coal mine. Mining activities had a certain impact on the accuracy of the identification model. In addition, compared with the four recognition models, PSO-LightGBM model had the highest recognition accuracy of 97.22%. It showed that the model had high accuracy, stability, generalization ability, and important reference value for the identification of mine water inrush source. [ABSTRACT FROM AUTHOR]

A certain flow plays a key role in preventing the shrinkage and drying of the river while maintaining good functionality. In recent years, ecological baseflow has become an important research issue in China with the emergence of ecological protection. Various ecological baseflow methods and their improvement methods were proposed and applied, but the reliability and applicability of the results are yet to be verified. This paper proposes an advanced ecological baseflow computation-dynamic thematic evaluation service model by considering the ecological protection objectives. The method was applied to five key cross-sections of the Weihe River, and a set of recommended ecological baseflow values was obtained considering the connectivity, water environment, and water-sediment balance, which is in line with the actual requirements. The analysis shows that the method has reliability and operability, which can provide support for management decisions. [ABSTRACT FROM AUTHOR]

Fish migrate up and down streams for reproduction in both sea and freshwater ecosystems over their life cycle. Over the last decades, fish passages have been provided to mitigate the adverse impacts induced by barriers. However, what is the proper type of fish passage and how to guarantee the effectiveness of operation are still under discussion. In this paper, global and China's policies on fish passages are reviewed. The development and main contents of relevant instruments are analyzed. The similarities and differences between China and foreign countries are compared, and issues in the fish protection and fish passages' management in China are identified. The results show that global policies on fish passages varied from local governments to continents. The design, operation, and management of fish passages are popular throughout the world. Duplication of authorities' responsibilities is the most critical issue in China. The paper recommends implementing a plan of environmental protection at watershed scale, and strengthening the monitoring of fish passages' operation and management. Further development directions of policies on fish passages' management have been proposed. The paper may help facilitate national policies on fish passages by integrating the effective measures of global experience. [ABSTRACT FROM AUTHOR]

This paper proposes a multi-reservoir operating policy for water supply by combining target storage curves with the hedging rule. The curves are derived to solve the allocation problem of joint demand. There are three steps in the proposed methodology: Firstly, the optimal release schedule using dynamic programming to solve a long-term operation model is established, from which the suitable forms of target storage curves are identified. Secondly, a simulation and optimization model is built to identify the key points of the curves with the hedging rule based on aggregated reservoir using improved particle swarm optimization (IPSO). Finally, synthetic inflow series is used to test and verify the efficiency of the proposed rule. The water-supply multi-reservoir system located in the Liaoning province of China is employed as a case study to verify the effect of the proposed operating policy and the efficiency of target storage curves. The results indicate that the proposed operating policy is suitable to handle the multi-reservoir operation problem, especially for periods of drought. The target storage curves also show improved performance for distribution of system storages. [ABSTRACT FROM AUTHOR]

The financial viability of a rainwater harvesting (RWH) system is highly determined by regional conditions such as rainfall pattern and water prices. Successful implementation of rainwater harvesting systems depends largely on the identification of suitable sites. This paper presents the water saving potential and economic effectiveness of rainwater harvesting systems across eight major cities in China, using a daily water balance model. Results show six to 81 days (or 1.6% to 22.2%) of dependability can be achieved by using a rainwater harvesting system over these cities. The annual water saving efficiency ranges from 10% to 37% and the benefit-cost ratio varies between 0.45 and 1.20 across the studied cities. South China achieves the maximum annual water saving and the highest benefit-cost ratio, while southeast China has the most regular profile of precipitation use. Northwest China was found to be the region with the worst performance, both in yearly water saving and in regularity of rainwater use on a yearly scale. It was also found that the RWH system is not financially feasible in the northeast, southwest and central plains due to the benefit-cost ratios being smaller than 1.0. [ABSTRACT FROM AUTHOR]

With the continuous operation of a water transfer project, especially under the general trend of global climate change in recent years, extreme weather occurs frequently, and the project's operation process will be tested by natural disasters, structural damage, electromechanical equipment failure, water pollution and other risks. Therefore, the risk management of the water transfer project is of great significance to ensure the long-term operation of the project. As one of the four largest cross-century projects in China, the operation risk of the South-to-North Water Transfer Project has attracted great attention. In this paper, a system dynamic model (SDM) for simulating real-time risk is presented. Based on the linear and directional characteristics of water transfer project and the known risk level of single buildings, DYNAMO language is embedded to connect the risks of various points on the line, and a model for real-time monitoring the risk changes along the line is constructed. The what-if analysis performed by the SDM shows the importance of human intervention to the deterioration and spread of dangerous situations in the process of engineering damage. [ABSTRACT FROM AUTHOR]

The wide application of drip irrigation under mulch in semi-arid agricultural regions in China not only improves agricultural water efficiency, but also affects formation of groundwater and the mechanism of water infiltration to a certain extent. This paper takes the typical semi-arid agricultural region in China as the research object. The movement of soil water under the three types of underlying surface was simulated by the Hydrus-2D model for the quantitative analysis of groundwater recharge. The influence of drip irrigation under mulch on groundwater infiltration depth and cumulative infiltration amount under different level years was simulated. Taking a normal flow year as an example, the simulated results showed that the maximum infiltration depth of drip irrigation under mulch reached 250 cm, which was greater than that of border irrigation (138 cm) and bare area (158 cm). The cumulative infiltration amounts of drip irrigation under mulch at 80, 120, 140 and 200 cm were respectively 1,484.8 m³/hm², 686.3 m³/hm², 554.1 m³/hm² and 238.1 m³/hm², which were greater than that of border irrigation and bare land at the same depth. The results proved that drip irrigation under mulch could increase the infiltration depth and cumulative infiltration amount, which is beneficial to groundwater recharge in semi-arid agricultural regions of China. [ABSTRACT FROM AUTHOR]

The scarcity of water resources has posed serious threats to the sustainable development of agriculture. China is a largely agricultural country with a large population, and agricultural water consumption accounts for more than 50% of the total water consumption. The application of water-saving irrigation is the main way to realize the sustainable development of water resources and economics. To comprehensively improve crop water-use efficiency and reduce agricultural water consumption, the Chinese central government have promulgated a series of agricultural water-saving policies since 2012, such as strengthening water management, increasing financial investment, and strengthening project construction and operation management and protection. Taking Jiangsu as an example, this paper reviews the main water-saving policies and measures of governments after 2012, as well as the conflicting interest between different water-saving participants. Results showed that, through water-saving policies and measures, its effective utilization coefficient of agricultural irrigation water (EUCAIW) has increased from 0.59 in 2014 to 0.614 in 2019. By 2019, the area of irrigated arable land controlled by water-saving technologies is 2.848 million hectares, accounting for 67.8% of the irrigated arable land area in Jiangsu. Jiangsu's water-saving policies have been implemented well, and it has guidance on water-saving reform work in other places. [ABSTRACT FROM AUTHOR]

Accurate forecasting of runoff is necessary for water resources management. However, the runoff time series consists of complex nonlinear and non-stationary characteristics, which makes forecasting difficult. To contribute towards improved forecasting accuracy, a novel combination model based on complementary ensemble empirical mode decomposition (CEEMD) for runoff forecasting is proposed and applied in this paper. Firstly, the original runoff series is decomposed into a limited number of intrinsic mode functions (IMFs) and one residual based on CEEMD, which makes the runoff time series stationary. Then, approximate entropy is introduced to judge the complexity of each IMF and residual. According to the calculation results of approximate entropy, the high complexity components are predicted by Gaussian process regression (GPR), the medium complexity components are predicted by support vector machine (SVM), and the low complexity components are predicted by autoregressive integrated moving average model (ARIMA). The advantages of each forecasting model are used to forecast the appropriate components. In order to solve the problem that the forecasting performance of GPR and SVM is affected by their parameters, an improved fireworks algorithm (IFWA) is proposed to optimize the parameters of two models. Finally, the final forecasting result is obtained by adding the forecasted values of each component. The runoff data collected from the Manasi River, China is chosen as the research object. Compared with some state-of-the-art forecasting models, the comparison result curve between the forecasted value and actual value of runoff, the forecasting error, the histogram of the forecasting error distribution, the performance indicators and related statistical indicators show that the developed forecasting model has higher prediction accuracy and is able to reflect the change laws of runoff correctly. [ABSTRACT FROM AUTHOR]

For the hilly-plain-wetland complex ecosystem in the cold region of Northeast China, in order to solve the problems, which include the scarcity of surface rainfall stations and the inability to provide accurate surface precipitation for hydrological process simulation, based on the observed precipitation of rainfall stations, three remote sensing precipitation products are taken as objects of evaluation. They include TRMM (Tropical Rainfall Measuring Mission) 3B42V7,3B42RT and CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data, CHIP). In this paper, the observation data of rainfall stations and IDWP precipitation data interpolated by IDW (Inverse Distance Weighted) are used as true value of precision comparison, and the detection accuracy of remote sensing precipitation products from 2001 to 2010 is evaluated on the time scale (day, month and quarter) and spatial scale in Naoli River Basin.The results of the study indicated that 3B42V7 and CHIP have a high detection accuracy for precipitation, and their CC (correlation coefficient) values are 0.47 and 0.49 respectively in daily time scale. The accuracy of their observation for monthly precipitation is better than that of daily precipitation, and the CC are 0.85 and 0.87 respectively. The multi-year average precipitation at different grid positions in the basin is overestimated by 3B42RT, and its evaluation results are poor at different time scales. For the precipitation intensity range of (0,20], the observed results of 3B42V7 and rainfall station are close to each other. For the precipitation intensity ranges of (0,1) and (50,þ∞), 3B42RT and CHIP have overestimated or underestimated the precipitation in different degrees. Based on the above analysis results, 3B42RT can be considered as data that can detect whether precipitation occurs on different spatial positions in the basin. 3B42V7 and CHIP can be applied to flood forecasting and nonpoint source pollution control in cold regions. [ABSTRACT FROM AUTHOR]

In general, accurate hydrological time series prediction information is of great significance for the rational planning and management of water resource systems. Extreme learning machine (ELM) is an effective tool proposed for the single-layer feedforward neural network in regression and classification problems. However, the standard ELM model falls into a local minimum with a high probability in hydrological prediction problems since the randomly assigned parameters (like input-hidden weights and hidden biases) often remain unchanged in the learning process. For effectively improving the prediction accuracy, this paper develops a hybrid hydrological forecasting model where the emerging sparrow search algorithm (SSA) is firstly used to determine the satisfying parameter combinations of the ELM model, and then the Moore– Penrose generalized inverse method is chosen to analytically obtain the weight matrix between the hidden layer and output layer. The proposed method is used to forecast the long-term daily runoff series collected from three real-world hydrological stations in China. Based on several performance evaluation indexes, the results show that the proposed method outperforms several ELM variants optimized by other evolutionary algorithms in both training and testing phases. Hence, an effective evolutionary machine-learning tool is developed for accurate hydrological time series forecasting. [ABSTRACT FROM AUTHOR]

In this paper, the ecohydrology measures including water management and interaction of ecological hydrology were considered to take a holistic view on the impact of climate, ecology, environment, and topography on different types of disasters. In the first step, the contents of the grim disaster situation and the information framework of ecohydrology with disasters were evaluated. Nest, the creation of ecohydrol- ogy and its work with related disasters were summarized. Three disasters including flood, drought, and geohazard were evaluated and three examples (Dujiangyan Irrigation Project, Karez, and Ecological slope) have been separately discussed for considering the concept of the pro- blem. Depending on the characteristics and potential for an effect in different disasters, there needed to be some challenges and opportunities for ecohydrology facing related disasters in various fields, such as National Space Planning, Sponge City and the ‘One Belt And One Road’ Initiative. Finally, some valuable conclusions were drawn on the application of ecohydrology to disaster prevention and miti- gation. Furthermore, the key systemic settings between water management, hydrology, and ecology were described, which is of the main importance for social disaster reduction, emergency management, and protection of accident prevention. [ABSTRACT FROM AUTHOR]

The West Liao River (WLR) Basin located in Inner Mongolia, is an important food production area in China. In recent years, the problem of groundwater over-exploitation has become increasingly prominent in the Basin due to the expansion of agriculture. This paper developed adaptive management initiatives of the local groundwater resources using Tongliao, located in the east part of the WLR Basin, as a case study. Groundwater management zones were divided based on hydrogeology, precipitation, land use, the groundwater over-exploitation areas, groundwater depth, and the administrative units (Banners/Counties/Districts). The Tongliao Basin was divided into 21 management zones. Subsequently, assessment rules for determining groundwater level thresholds in each groundwater management zone were developed based on groundwater observation conditions and the current groundwater depth. Based on the assessment rules, in 2020 the management threshold of groundwater level for each zone were determined. The results provided a scientific basis for the ‘Water Availability Based Local Development Initiative’ in the Tongliao Plain. [ABSTRACT FROM AUTHOR]

Water shortages have become a major constraint on China’s industrial development. Iron and steel industrial parks have a huge demand for water resources and complex production technologies. Therefore, it is very important to study the distribution, transfer and loss of water resources in industrial parks in order to improve the ability to refine water resources management. The purpose of this study was to reveal the water flow in industrial parks by using the principle of water balance and to provide a method for quantification and characteristic recognition of water resources in industrial production processes. In this research, an iron and steel industrial park in North China was chosen as the case study. In order to calculate the water balance of the whole steel production processes, the industrial park was divided into four levels and 110 water units according to the pipe network system and production processes. Based on the results of multi-level and multi-node water balance, this paper analyzed the water intake structure and water consumption structure of industrial parks, and provided the methods to optimize the allocation of water resources and reduce the consumption of fresh water in industrial production processes. The results of the study showed that the energy department accounted for 60.8% of the total water withdrawal of the industrial park. There were 6,249 m3 /day of fresh water in the industrial park, which could be replaced by reclaimed water from urban sewage. Evaporation and pipe network leakage were the main water consumption factors in the steel park, which contributed 91.3% of the water consumption. Under the guidance of the research results, the evaporation water consumption of the industrial park was reduced by 8,412 m3 /day, and pipe leakage was reduced by 600 m3 /day. This article demonstrates the application of the water balance principle in complex water use systems, which is helpful for water resources management based on water use processes. [ABSTRACT FROM AUTHOR]

Achieving high-quality economic development under the new development pattern has become an inevitable requirement for China’s economic development. Correctly calculating the value of water resources and optimizing the price mechanism of water resources is one of the important guarantees for promoting the high-quality development of the regional economy. Based on this fact, this paper takes Hubei Province as an example to construct a coupling relationship model between water resources and economic high-quality development and to evaluate the coupling coordination between the two. And then, the fuzzy comprehensive evaluation model is used to evaluate the value of water resources in Hubei Province, and recalculate its water price. The results show that Hubei province now is a lagging development of water resources, and the current water price is far lower than assessed. The government should improve the mechanism of water price which should be driven by innovation to adjust the water use structure, finally achieve high-quality economic development of Hubei Province. [ABSTRACT FROM AUTHOR]

With the acceleration of urbanization, the demand for water, energy and food (WEF) keeps increasing. However, the infrastructure construction leads to a sharp decline of cultivated land, water area and forest land, so the importance of ecological space management should be recognized. Based on ecological footprint theory, this paper proposes the WEF footprint and first attempts to explicitly examine the relationship between economic growth and WEF footprint by investigating the existence of an Environmental Kuznets Curve (EKC). GLS regression and the LOWESS model are used to explore the economic growth and WEF footprint nexus in the eight economic zones and the three regions of China. The results indicate that besides the traditional EKC shapes, an M-shape exists, and the proportion of the M-shape curve (12.5%) is lower than the traditional EKC (87.5%). The results showed that the LOWESS model may be more conducive to reflect the real relationship between economic growth and WEF footprint. According to the analysis, the policy suggestions are put forward to promote the sustainable development of the water-energy-food system. In addition, the study can provide some ideas for solving the contradiction of land use. [ABSTRACT FROM AUTHOR]

The integrated agricultural water pricing reform (IAWPR) is by far the most systematic, complex and longest reform in the agricultural sector of China. It has lasted for decades from the stage of reform exploration to the current reform development. IAWPR can effectively address resourced price distortion and promote rational allocation of agricultural water resources. By improving China’s agricultural water pricing mechanism, government agricultural subsidy mechanism, water-saving incentive mechanism, operation and management (O&M) mechanism of irrigation systems and water quota mechanism, the reform will promote water conservation in agriculture and ensure the effective operation of irrigation systems. It is a major strategic decision made by the Chinese government to address the water security challenges facing sustainable development. This paper reviews the course of the reform, introduces the policy design, key tasks and implementation of the reform, and takes Jiangsu Province as an example to demonstrate the effect of the reform, but also discusses the problems existing in the reform. [ABSTRACT FROM AUTHOR]

An Interconnected River System Network (IRSN) project could change the drainage pattern and influence the river's ecological health. However, the relevant research is still in a preliminary stage and needs to have a supplement. Considering environmental and ecological characteristics of the karst area, this paper analyzed the relationship between IRSN projects and environmental indicators, and proposed a multi-layer indicator system that has three first-class indicators (water environment, river--lake organism, connectivity) and 15 secondclass indicators for assessment of the ecosystem. The weight of each level of indicators' can be determined using the analytic hierarchy process (AHP), and the change rate of indicators critical value is normalized, then five threshold levels are established within the range of 0-1. Refer to the established response mechanism and threshold level of the karst basin, The Wangerhe River project taken as an example can well reflect the IRSN status through this method. These results can provide scientific support for constructing an evaluation index in other karst areas. [ABSTRACT FROM AUTHOR]