State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
Dr. zhaohui yang
State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
Agricultural water and land resources are key elements of human production and their unbalanced distribution has threatened the sustainable development of agriculture and regional food security. This study is aiming to investigate the spatial–temporal changes of matching characteristics between agricultural water and land resources in Ningxia during 2007 to 2017. The agricultural irrigation water (AIW), farmland area (FA) and effective irrigated area (EIA) were selected as quantity parameters for agricultural water and land resource. Results show that the gravity centers of AIW and EIA both moved in the southeast direction, while the gravity center of FA moved northwestward, which indicated a better spatial matching degree between AIW and EIA. According to the Gini coefficient and total spatial mismatch index, the spatial mismatch between AIW and FA of Ningxia was remedied and that of AIW and EIA was worse. Counties with sufficient and insufficient AIW were distributed in the north and the south of Ningxia, respectively. The sensitivity of agricultural irrigation water to land resources remarkably increased in the study period, particularly for the counties in northern area of Ningxia. The findings may provide implications for effective management of regional agricultural water and land resources.
A major objective of the optimization of water resources allocation is to ensure the supply an adequate amount of water to users at the right time and maximize the utilization of water resources. However, in case of insufficient water supply, water shortage is likely to occur intensively for specific water users or in specific periods, referred to as a “concentrated water shortage”. The risk of a concentrated water shortage should be shared across a wider range of users and periods, so that it would have a less severe impact on each calculation unit in each period, which we refer to as the “wide-mild water shortage”. In this study, the nonlinear weight of the water supply objective function can be converted into a piecewise linear weight based on the law of diminishing marginal utility, making it possible to reduce or even eliminate the concentrated water shortage and thus making the allocation of water resources more reasonable. The case study in the Nen River basin in northeast China shows that the improved method results in a significant increase in water shortage units but a significant reduction in water shortage range. As a consequence, water shortage is more uniformly distributed from April to June, which contributes to solving the concentrated water shortage problem in May. However, it should be noted that to what extent the wide-mild water shortage can be realized depends not only on the marginal utility of water demand, but also on the available water supply and the regulative capacity of water supply projects. In spite of this, the improved method enables water to be supplied more suitably for users at the appropriate time, which contributes to improving the utilization of water resources and helping decision-makers better address the problem of concentrated water shortage.
Agricultural economy is usually studied by total factor analysis, while it is uncertain what factors affect agricultural production in the perspective of water utilization. The aim of this study was to investigate driving forces of agricultural economy related to water utilization effects in Ningxia during 2007 to 2017. The logarithmic mean Divisia index (LMDI) method was selected to decompose the driving forces of agricultural production value. Results showed that the agricultural production value increased significantly in 2007–2017 in all of Ningxia and in each city. In terms of the whole region, the effect of agriculture water efficiency played a leading and positive role in the increase of the agricultural production value. The effects of water stress, water utilization structure, and water resource endowment all showed a negative driving force, while population exerted a positive effect. For five cities, the effect of agriculture water efficiency and water utilization structure showed no spatial difference; whereas the other effects expressed different driving forces between cities in the northern plain area and southern hilly area due to varied natural conditions and agricultural activities. The results of this research suggested that the first and foremost strategy of agricultural development and water resource management in Ningxia should be to promote water-saving irrigation and optimize agricultural structure.
China is in a period of rapid urbanization. Due to the high concentration of population and industries, the loss due to flood and waterlogging is becoming more and more serious. Therefore, it is of great significance to strengthen the analysis and evaluation of the losses due to flood and waterlogging disasters in China for the recent years. This study analyzed the losses caused by flood and waterlogging disasters in China from 2006 to 2017. The results showed that the most serious year affected by floods and waterlogging was 2010. However, the relationship between rainfall and flood disaster losses was not significant, which may be because the occurrence of flood disasters is caused by many factors. The spatial distribution showed that the eastern and southern parts of China suffered greater losses from the flood and waterlogging disasters because these areas are more vulnerable to floods and waterlogging disasters under the impact of both monsoons and typhoons. This study hopes to provide some reference for flood disaster control and disaster mitigation in the future.
The conflict between urban energy supply and demand is becoming increasingly evident. One aspect that consumes a great deal of this energy is the allocation of urban water resources. This study proposes a new scheme for rationally allocating urban water resources considering the high levels of energy currently consumed in Jinan city of Shandong, China. The focus is on simultaneously minimizing energy consumption and water shortage rates and granting priority to public water supplies in line with the predicted water supply levels for all available sources. Based on this assessment, further adjustments were made in terms of system configuration and the analysis of energy consumption. The results of the general water resource allocation model not only show that Jinan’s total water supply in 2030 will increase by 33.7% from 2019 but that energy consumption will also increase by 58.5%. If energy consumption is constrained and water supplies are restricted for high-energy-consumption activities, the results of the water resource allocation model considering energy consumption show that energy consumption will increase only by 44.2%. And the results also show that local groundwater is less energy intensive than imported surface water, which suggests that groundwater should be preferred (at least for energy reasons). Through modeling to reduce the total energy consumption in water resource allocation, this paper can provide a reference for energy saving for urban water supply systems.