Analysis and Prediction of Sustainable Utilization of Water Resources in Chengde City Based on System Dynamics Model

In addition to the social economy and the rapid development of industry and agriculture, water demand is increasing and poses challenges in the over-exploitation of water resources. This research establishes a model to assess the sustainable exploitation of water resources based on system dynamics theory and STELLA software, which solves the imbalanced allocation of industrial water, agricultural water and domestic water. The model is composed of two parts: the water quantity system (including economy, population, water availability and water demand) and the water quality system (composed of the aquatic environment), which is suitable for Chengde City with a water resource shortage. The proposed model is established by data of Chengde City from 2007 to 2016 and is verified by 2017 data. Furthermore, in order to compare the water quality and water utilization of Chengde City under different development scenarios up to 2025, the sensitivity analysis of each variable (e.g., population) is carried out in this model, and thereby the water resource utilization scenarios are acquired. Specifically, four scenarios are designed and denoted: Scenario 1: keeping the status quo unchanged, Scenario 2: slowing down economic development and devoting more energy to environmental protection, Scenario 3: only focusing more on economic development and Scenario 4: aiming at steady and rapid economic growth and an eco-friendly environment. The results shows that Scenarios 2 and 3 facilitate high-effective water resource utilization compared with the current development, Scenario 1. Scenario 4 fosters the balance of water resources supply–demand in the future and preserves the water quality. This study provides an inspiring method for realizing the sustainable utilization and optimizing allocation of water resources in Chengde City.

Green water resource utilization efficiency in urban agglomerations: measurement, spatiotemporal variations and influencing factors

Green development is the coordinated development of the economy, society and environment and has become a mainstream development model. This paper evaluates the green water resource utilization efficiency (GWRUE) of 38 regions in the four-city area in central China during 2010–2019 using a super-slacks-based measure (super-SBM) DEA model considering unexpected output. Then, the spatiotemporal variations in GWRUE are analyzed by the standard deviational ellipse method, and the geographical detector method is employed to reveal the dominant impacts and interaction impacts on GWRUE spatiotemporal variations. The results show that (1) from 2010 to 2019, the GWRUE in the four-city area in central China was low, and the difference among regions was obvious, showing a downward trend. (2) From 2010 to 2019, the spatial gravity center of GWRUE experienced a change process from northeast to southwest, and its moving speed showed a “waveform” rising trend. Moreover, the SDE range of each characteristic time point showed a decreasing trend, indicating that the spatial variations in GWRUE tended to be agglomerated. (3) From 2010 to 2019, the influence of each factor on the spatial variations in GWRUE was different each year. In addition, the two-way interactions between different influencing factors were mainly manifested as bivariate enhancement relationships and nonlinear enhancement relationships and were especially affected by multiple factors that produce a nonlinear enhancement interaction. This study can provide a practical basis for realizing water ecological civilization construction and high-quality development in the four-city area in central China.

The “Groundwater Benefit Zone”, Proposals, Contributions and New Scientific Issues

The groundwater has great potential for water resource utilization, accounting for about a quarter of vegetation transpiration globally and contributing up to 84% in shallow groundwater areas. However, in irrigated agricultural regions or coastal areas with shallow groundwater levels, due to the high groundwater salinity, the contribution of groundwater to transpiration is small and even harmful. This paper proposes a new conception of groundwater benefit zone in the groundwater-soil–plant-atmosphere continuum (GSPAC) system. Firstly, it analyzes the mutual feedback processes of the underground hydrological process and aboveground farmland ecosystem. Secondly, it elaborates on the regional water and salt movement model proposed vital technologies based on the optimal regulation of the groundwater benefit zone and is committed to building a synergy that considers soil salt control and groundwater yield subsidies. Finally, based on the GSPAC system water-salt coupling transport mechanism, quantitative model of groundwater benefit zone, and technical parameters of regional water-salt regulation and control, the scientific problems and development opportunities related to the conception of groundwater benefit zone have been prospected.

Use of Remote Sensing to Assess the Water-Saving Effect of Winter Wheat Fallow

Winter wheat fallow policy has a greater effect on water resource management, and the water-saving effect in the fallow process of winter wheat can provide data support for precise water resource utilization planning. In order to evaluate the water resource consumption of winter wheat and the related effect from winter wheat fallow, this study searched the changing trends of cultivated land evapotranspiration under five different scenarios through the object-oriented extraction method and a SEBS model based on multi-source data. The results indicated that the evapotranspiration during winter wheat growing period was higher than that of winter wheat fallow land, and there was no big difference in evapotranspiration between the fallow land during harvesting and the emergence of new crops. The evapotranspiration of winter wheat was higher than that of various fallow land, and the evapotranspiration of abandoned land was higher than other fallow land in the winter wheat growing season. From this point, this study concludes that the fallow land policy can effectively reduce evapotranspiration during the growing of winter wheat, which is conducive to the sustainable exploiting of water resources.

Assessing Water Footprint of Copper Production by Pyrometallurgy

As an important tool for water resource environmental impact assessment, the application of water footprint assessment method in copper production process is conducive to more accurate assessment of water resource environmental impact in copper production process. The water footprint assessment method released by the Water Footprint Network was used to study the water footprint of the production process of cathode copper products produced by pyrometallurgy. It was found that the water footprint of 1 ton of copper produced by pyrometallurgy was 242m3, of which the blue water footprint accounted for 60%, the grey water footprint accounted for 40%. The direct water footprint accounted for 67% and the indirect water footprint accounted for 33%. The characteristics of water footprint contribution at each process were compared, which provided data support and reference for enterprises to better understand the water resource environmental impact of copper by pyrometallurgy and to choose the water resource utilization mode with their own production characteristics.

Basics of systems approach to methodology of assessing waterworks facili-ties on natural environment

According to the regulatory and environmental requirements on operating waterworks facilities referred to as objects of activity, the environmental influence of these facilities must be assessed in terms of water resource utilization, which is exactly the goal of this study. The basics of the methodology of this assessment are developed by the system approach centred around the notion of System. The results of studying the interaction of the object of activity (OA) with the natural environments (NENV) of the basin geosystem are used in developing the basics of the methodology of environmental influence assessment (EIA). The study results have been used in designing and building hydropower engineering facilities in the North Caucasus in the South of Russia.

Treated Wastewater Irrigation—A Review

As the most important resource for life, water has been a central issue on the international agenda for several decades. Yet, the world’s supply of clean freshwater is steadily decreasing due to extensive agricultural demand for irrigated lands. Therefore, water resources should be used with greater efficiency, and the use of non-traditional water resources, such as Treated Wastewater (TW), should be increased. Reusing TW could be an alternative option to increase water resources. Thus, many countries have decided to turn wastewater into an irrigation resource to help meet urban demand and address water shortages. However, because of the nature of that water, there are potential problems associated with its use in irrigation. Some of the major concerns are health hazards, salinity build-up, and toxicity hazards. The objectives of this comprehensive literature review are to illuminate the importance of using TW in irrigation as an alternative freshwater source and to assess the effects of its use on soil fertility and other soil properties, plants, and public health. The literature review reveals that TW reuse has become part of the extension program for boosting water resource utilization. However, the uncontrolled application of such waters has many unfavorable effects on both soils and plants, especially in the long-term. To reduce these unfavorable effects when using TW in irrigation, proper guidelines for wastewater reuse and management should be followed to limit negative effects significantly.

A study on the effects of regional differences on agricultural water resource utilization efficiency using super-efficiency SBM model

This study evaluated the water resource utilization efficiency and resource consumption for planting, forestry, animal husbandry, and fishery in various regions of China. Using the super-efficiency Slacks-Based Measure (SBM) analysis method, the main agricultural pollution emissions (Chemical Oxygen Demand, ammonia nitrogen, and agricultural carbon emissions) were proposed as environmental constraints for the first time. The threshold regression model was used to measure the impact of agricultural water use efficiency on agricultural water consumption by constructing seven different explanatory variables. The results show that the overall utilization efficiency of agricultural water resources in China presents a fluctuating downward trend, and the regional differences are significant. A single threshold effect on agricultural water consumption was found in five variables: per capita water resources, disposable income, dependence on foreign trade, industrial structure, and Gross Domestic Product. The increase in each parameter will have a positive effect on agricultural water consumption. The relationship between agricultural water use efficiency and agricultural water use was non-linear when the government's attention and the rural labor force were used as threshold variables.

The Effect of Water Rights Trading Policy on Water Resource Utilization Efficiency: Evidence from a Quasi-Natural Experiment in China

Water shortage has become a serious problem in the world, and low water efficiency is the key to industrial and agricultural production and sustainable economic development. Based on the data of 30 provinces (municipalities) in China from 2010 to 2017, this study builds a DEA model based on the hybrid network structure of water systems to measure water resource utilization efficiency and uses a difference-in-differences (DID) model to examine the effects of the water rights trading policy on water resource utilization efficiency. We find that the water rights trading policy can significantly promote the total water efficiency of the water resources system and the initial water use efficiency, and after a series of robustness tests, the result is still valid. Further analysis indicates that the policy effect changes with the adjustment of the industrial and agricultural water use structure. Moreover, the dynamic impact of water rights trading policy on water resource utilization efficiency is still significant. This study provides macroscopic evidence for evaluating the effects of China’s water rights trading policy and offers new ideas and experiences for improving China’s water resource utilization efficiency.