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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]

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]

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 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]

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 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]

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]

Land Use/Land Cover (LULC) is a main factor that affects the hydrological process of catchments. A better understanding of its influence is of great significance to future land use planning and water resources management. Since 2011, the local government has implemented a land remediation plan, and the LULC in the Yanghe Reservoir Basin has undergone major changes. This paper uses The Soil and Water Assessment Tool (SWAT) model to study blue water (BW) and green water (GW) resources in three typical years (a wet year, dry year, and normal year) under two LULC scenarios in the basin in 2010 and 2017. The results show that from 2010 to 2017, the area of cultivated land and residential construction land increased by 227.28% and 269.23%, respectively; the area of unused land, woodland, and grassland decreased by 98.84%, 35.90% and 39.52%, respectively. Compared with the results of the 2010 LULC scenario, the average BW of the three typical years under the 2017 LULC scenario decreased by 11.66%, 52.32%, and 21.95%, respectively, and the average GW flow increased by 6.72%, 2.90%, and 6.83%, respectively, and the average GW reserves decreased by 14.80%, 11.39%, and 7.67%, respectively. Therefore, this study believes that changes of LULC have led to a significant decrease in runoff and an increase in evapotranspiration in the basin. [ABSTRACT FROM AUTHOR]

With the rapid development of urbanization and the continuous improvement of living standards, China’s domestic water consumption shows a growing trend. However, in some arid and water deficient areas, the shortage of water resources is a crucial factor affecting regional economic development and population growth. Therefore, it is essential to reliably predict the future water consumption data of a region. Aiming at the problems of poor prediction accuracy and overfitting of non-growth series in traditional grey prediction, this paper uses residual grey model combined with Markov chain correction to predict domestic water consumption. Based on the traditional grey theory prediction, the residual grey prediction model is established. Combined with the Markov state transition matrix, the grey prediction value is modified, and the model is applied to the prediction of domestic water consumption in Shaanxi Province from 2003 to 2019. The fitting results show that the accuracy grade of the improved residual grey prediction model is “good”. This shows that the dynamic unbiased grey Markov model can eliminate the inherent error of the traditional grey GM (1,1) model, improve the prediction accuracy, have better reliability, and can provide a new method for water consumption prediction. [ABSTRACT FROM AUTHOR]

The paper uses the super-efficiency data envelopment analysis (DEA) model to measure the water resources utilization efficiency of 30 provinces in China, and then uses the system generalized method of moments (GMM) model to analyze the impact of environmental regulations on China’s regional water resources utilization efficiency. Conclusions as follows. (1) The overall water utilization efficiency is low, and the regions are very unbalanced. The more efficient areas are concentrated in the east, and the less efficient areas are in the west. (2) There is a ‘U’-shaped relationship between the intensity of environmental regulation and water resource utilization efficiency, that is, weaker environmental regulation intensity is not conducive to the improvement of water resource utilization efficiency, but when the intensity of environmental regulation crosses the ‘inflection point’, it can promote the improvement of water resources utilization efficiency. (3) The level of economic development has a very significant positive effect on water resources utilization efficiency, and the coefficient of scientific and technological progress is positive, but the impact of scientific and technological input on water resources utilization efficiency is limited and not significant; industrial structure and water resource utilization efficiency shows a negative correlation; water use structure and water resources efficiency show a negative correlation. [ABSTRACT FROM AUTHOR]

In order to distribute water resources reasonably, it is advantageous to make full use of resources and produce high economic and social benefits. Taking the Dujiangyan irrigation area of China as an example, we discuss the idea of establishing and solving the optimal allocation model of water resources. With this aim, a two-dimensional constraint model with highest economic value, minimum water shortage, minimum underground water consumption and necessary living water demand was established. In order to solve this model, we improved a multi-population genetic algorithm, extending the genetic optimization of the algorithm into two dimensions, taking population as the vertical dimension and the individual as the horizontal dimension, and transforming the cross genetic operator to copy the genetic (crossover) operator and the mutation operator to only act on the vertical dimension, so as to optimize the allocation of such discrete objectives of water resources in the irrigation area with a particular model suitable for the region. The distribution results successfully control the water shortage rate of each area at a low level, which saves the exploitation of groundwater to the maximum extent and produces high economic benefits. The improved algorithm proposed in this paper has a kind of strong optimization ability and provides a new solution for the optimization problem with multiple constraints. [ABSTRACT FROM AUTHOR]

Xi'an has a special historical position in ancient China, and it has made great achievements in water conservancy projects in all dynasties. The water network skeleton formed mainly by the 'Eight Waters' in the territory, along with the historical changes of Xi'an, has experienced the Lantian ape-man 'living by the water', the Western Zhou Fenghao 'two capitals along the Fenghe River', and the Qin Xianyang city 'capital passed by Weihe river'. Developments and changes such as the 'diversion of water to develop the capital' in Chang'an in the Western Han Dynasty, the 'capital be ringed by eight rivers' in Chang'an in the Sui and Tang Dynasties, 'reduced water' from the end of the Tang Dynasty to the Qing Dynasty, and the 'coordinated supply' after the founding of the People's Republic of China. After sorting out the system, it is believed that the 'Eight Waters' in the territory are the original driving force for the flourishing Chang'an in history. From ancient times to the present, with the development of industry, there has been a trend that human settlements and rivers are farther away. Urban water supply has shifted from groundwater sources to surface water sources. This article investigates the evolution of water conservancy projects in Xi'an from the Paleolithic Age to the present, and studies the relationship between human production and life and water resources. The changing law and development trend of the water supply structure in Xi'an urban area in modern times are analyzed. We have summarized the enlightenment left to us by the practice of water conservancy projects for thousands of years. This paper provides references for the development and planning of water resources in similar cities. [ABSTRACT FROM AUTHOR]

In this paper, a Data Envelopment Analysis-Tobit (DEA-Tobit) two-stage model was used to evaluate the efficiency of water-resource utilization, and the regional differences and influencing factors on water-resource utilization were analyzed. The results of the analysis of regional differences show that China's water-use efficiency is relatively low. Only Beijing, Shanghai, and Fujian have water-use efficiency higher than 0.8, whereas most other provinces and cities have an efficiency of 0.3--0.8. The eastern region demonstrates a higher water-resource utilization efficiency than the central and western regions. The analysis of the influencing factors of regional differences in water-use efficiency found that per capita water resources, per capita domestic water use, and the proportion of primary and secondary industries all have a negative impact on the efficiency of water use, and per capita GDP has a positive impact on the efficiency of water use. Agricultural water consumption, industrial water consumption, domestic water consumption, and total ecological water consumption all have a negative impact on water-resource utilization efficiency, of which domestic water consumption and industrial water consumption have a greater impact. Technological level and water-resource utilization efficiency show a significant positive correlation. [ABSTRACT FROM AUTHOR]

This paper is distinct from existing studies on water resources carrying capacity which usually use dimensionless data to represent trend and status of water resources carrying capacity. Here, on the grounds of the most stringent water resource management system and following the principles of water determining population, water determining city scale, water determining production and so on, water resources carrying capacity prediction model was established. The water resources carrying capacity was represented by population, which can directly reflect the status of water resources. Under the rigid constraints of water use quantity and water use efficiency, six scenarios were set to predict China's maximum population in 2030. The results demonstrated that the maximum population in each scenario is close to 1.45 billion of National Population Development Plan. It means water resources rigid constraints can support population and economic growth at the socio-economic development current pace and path. Total water use quantity will not break through the limit of 800-900 billion m3 when achieving the expected goals of social and economic development, not even more than 700 billion m3. Meanwhile, in order to relieve water resources stress, to improve water resources carrying capacity, and to accelerate construction of a water-saving society, some suggestions were put forward. [ABSTRACT FROM AUTHOR]

Baseflow is crucial to maintaining river flow during low-rainfall periods. The baseflow estimation is important to water supply and ecological environmental protection in the Yellow River Basin (YRB), China. This paper comprehensively assessed the applicability of four single-parameter digital filtering, recursive digital filtering, and HYSEP (streamflow hydrograph separation) methods across four typical catchments in the Yellow River Basin: the Zuli River Basin, the Kuye River Basin, the Tuwei River Basin, and the Jingle sub-basin. We also investigated annual and monthly variations in baseflow. We found the standard deviation and coefficient of variation of baseflow index through recursive digital filter were relatively small. And the baseflow process line was smoother and more reasonable in typical year and typical storm-flood events, which conformed to the damping and hysteresis effect of the underlying surface. Thus the recursive digital filter method had the best performance, which was recommended for baseflow separation in the YRB. The estimated baseflow index of typical basins were between 0.354 and 0.502. In addition, inter-annual baseflow showed a decreasing trend and intra-annual baseflow was characterized by uneven distribution, which was subject to the characteristics of each basin. [ABSTRACT FROM AUTHOR]