Study On Several Critical Problems In Water Resources Planning Of Remote Intake Area Of Trans-basin Diversion Project

Water is the fundamental substance for all lives on the earth. The development of human society cannot live without the exploitation and utilization of water resources. In recent years, Water shortages are already a major issue in many regions with China’s rapid development of economic and social. Due to the unbalanced distribution of water resources, interbasin water transfer has become an important way to solve the water crisis in China. Water diversion projects are often long and complex route, which some remote intake areas are often the most important replenishment of the water diversion project because these areas have significantly political and economic position.Due to remote intake areas are far away from water resources area, their hydrologic characteristics are significantly different. And constructions technical are difficulties and the investments are high. If the preliminary planning of remote intake areas is wrong, the large amount of engineering will cause huge economic losses; or the determined volume of water is too small, the problem of water scarcity has still not been solved fundamentally in intake area. Therefore, it is great significance to study the water resources planning in remote intake area for the implementation and operation of the water diversion project.Of many problems, the most basic and critical points are the analyses of water resources system and water demand prediction in intake area. For remote intake area, the hydrological properties are often great different from water source area, the joint hydrological characteristics of remote area and water resources area are crucial to the formulation of the transfer scheme. In this paper, the remote intake area in EW inter-basin water transfer project are taken as a research object, some research on these problems above were done The main research contents and results are as follows:(1) Analysis on the utilization change of water in intake area. A complete decomposition method-log mean divisia index method (LMDI) is introduced for analyzing the change of water use because general factor decomposition leaves over residual. Through the application in the intake area of EW water transfer project, it shows that:the residuals of Laspeyres decomposition (LAS) and Paache decomposition (PAA) are large, these two methods should be used with caution; the residual of Arithmetic Mean Divisia Index decomposition (AMDI) is much small, LMDI has the best decomposition effect, its residual is (2) The water demand prediction in intake area. At present, the prediction accuracy of water demand is not satisfied due to the mechanism analysis on water utilization is lacked. In this paper, a new forecasting model is developed by analyzing the correlation between water drive factor and its corresponding drive water based on the derivation of completely factor decomposed and non-complete factor decomposition formula. Through the application in the intake area of EW water transfer project, it shows that the prediction accuracy of this method is high and the method has great practical value.(3) Evaluate the levels of water sustainable use in intake area. Due to the severe shortage of water resources, the ecological environment is often weak in intake area of water transfer project; water supply subsystem and ecological environment subsystem have a great influence on the whole water system. Taken into account such characteristics, an index system is constructed from the four aspects:water supply level, water use level, socio-economic level and ecological environmental level. The variable fuzzy evaluation model and radial basis function networks (RBF) are adopted by considering the complexity and vagueness of the composite system of regional water resources. Through the evaluation on the intake area of EW water transfer project in1980-2009and2015, the "state" and "potential" of water resources utilization in the intake area are analyzed, and the diversion scenarios are compared with non-diversion scenarios.(4) Study on the evolution of water resources composite system in intake area. Understanding the evolution mechanism of water resources composite system is the foundation of monitoring and regulation of the development of socio-economic and water environment in intake area. Logistic growth model can not reflect the diversity of evolution pattern in the analysis on water resources complex system. So, Richards model is introducted to describe the evolution of water resources composite system based on the analysis on the characteristics of sustainable development of the composite system of regional water resources. Depending on the speed of system development, the evolution of the composite system of regional water resources model is divided into the type of rapid rise, the the type of slow rise and the type of symmetry. And the long-term evolution of the complex system of regional water resources for sustainable development is analyzed by using self-organizing evolutionary theory. It shows that the long-term evolution of the water resources system is not completely continuous path, but the combination of continuous gradient and intermittent fluctuations. Fluctuations imply the new opportunities and dynamics of development. Fluctuation phenomenon should be given greater prominence, but not be ignored because the water resources systems are more vulnerable in intake area. This is of great significance for improving the stability and robustness of the receiving area of water resources systems. Finally, the evolutionary characteristics of the intake area of EW water transfer project are analysized by using Richards evolutionary mechanisms.(5) Analysis of asynchronism-synchronism of regional precipitations in inter-basin water transfer areas. The local characteristics of multi-dimensional random variables are seldom considered in general modeling method of multivariate copula. A new modeling method, so called Pair-Copula Construction, is introduced to remedy this defect. Different types of copula distribution functions are allowed to be introduced in this method. Correspondingly, the related characteristics of complex multivariate can be described by a cascade of pair-copula acting on two variables at a time. In the analysis of asynchronism-synchronism of regional precipitations in EW inter-basin water transfer areas, pair-copula construction method is compared with general modeling method of multivariate copula. It shows that the local dependence structure would exist among hydrologic variables even in three dimensional cases. In this situation, general modeling method of multivariate copula would face difficulties in fitting distribution. However, pair-copula construction could capture the local information of hydrologic variables efficiently by introducing different types of copula distribution functions.