Analyzing The Carrying Capacity Of Water Resources In Beijing Based On Virtual Water Theory

Water is an important strategic resource for the survival and development of human beings. And it plays an irreplaceable role in the emergence and development of the human civilization. The demand of the water resource has also increased rapidly due to the development of economy and society and the improving living standards. In the context of the soaring world population, water resource scarcity has become the global problem. As people have encountered the global resource shortage and the destroyed ecological environment, they proposed the principles of sustainable development by identifying their past impacts on the environment. To achieve sustainable development in the development and utilization of natural resources, we can not exceed the limits that the environment can withstand. That is, the exploitation and utilization of water resource must be within the limit of the regional water resource system carrying capacity. Overall, the scientific analysis of water resource carrying capacity is the foundation to formulate the economic policy, urban planning, population development planning and environment protection plans etc.This paper puts forward the water resource carrying capacity analysis on the basis of water resource carrying capacity and virtual water theory studies. It demonstrates the importance of extending the water resource carrying capacity study to the virtual water theory which could more precisely reflect the utilization of Beijing water resource and the actual water resource carrying capacity. In this method, sustainable development principle is used as the guidance and regional water resource conditions are considered as the foundation. On the basis of the virtual water theory research, people could identify the high water consumption products by analyzing the data of regional virtual water content. Then by virtue of implementing virtual water strategy, people could introduce the external alternative products in order to raise regional net virtual water inflows. The increased regional net inflows can reduce the local water resource consumption of high water consumption products and the saving part can be distributed to industries, living and environment. As a result, the regional water resource carrying capacity could be increased.Based on the study of virtual water theory and calculation methods, this paper analyzes the water resource carrying capacity of Beijing.2010is selected as the base year, meanwhile2020and2030are considered as the planning level year. In the first place, it analyzes the water resource carrying capacity in different hydrological conditions, and then indicates the overload conditions and the necessity of implementing virtual water strategy,and analyze the possible effects of climate change on water resources carrying capacity which base on climate prediction results. After this, it simulates the model of distributing the "blue water" which is the reduced virtual water from the irrigation local crop, and save it for the third industry and domestic use. Therefore, it could improve the water resource carrying capacity of Beijing. The results, based on the calculations of water resource carrying capacity and virtual water, indicate that:firstly, when the virtual water strategy implementation is not increased, the carrying capacity of water resource in Beijing is greater than1, and it is in the overload condition; secondly, the virtual water of grain, vegetables and fruits as well as pork, beef and lamb are relatively higher, thereby the planting and breeding scale of such products should be reduced. Meanwhile, by increasing the external input of alternative products, it could improve the water resources carrying capacity and alleviate the overload pressure by cutting down the water consumption of crop planting and livestock breeding.