Studies On Structure Adjustment Of Agricultural Water Based On Virtural Water In Sanjiang Plain

Sanjiang plain is the important commodity grain base in our country. Agriculture is the foundation of the national economy; water conservancy is the lifeblood of agriculture, related to national security and stability. But for many years, shortage of water resources has caused economic development and instability of society. Agriculture is a large family of water, and agricultural water ratio affects all other industry water. Because of excessive pursuing the economic efficiency, the rice area has been increased rapidly and planting structure is single in Sanjiang plain.80%of the agricultural irrigation water comes from underground. At present groundwater is excessive exploited, and surface water use is not sufficiently, all of these lead to serious imbalance of agricultural water in Sanjiang plain. So in Sanjiang plain area water science research focus and the key problem are to reduce agricultural water proportion, and to solve each industry water contradictions between the regional and the internal area. Therefore, under the premise of ensuring the national food security and regional water and ecological safety, reasonably using agricultural water resources, and realizing sustainable use of agricultural water resources seem especially important. To realize our country’s water safety, especially in agriculture water, the water resources management system and mechanism must be researched and updated.This article mainly aimed at the problems of the agricultural water resources utilization in Sanjiang plain, taking the virtual water theory as the guide, and taking Sanjiang plain JianSanjiang reclamation for the study area. The paper systematically analyzed the theoretical connotation of the virtual water, using Theil coefficient and Gini coefficient to measure virtual water content of agricultural products in15state-owned farms calendar year, and set up the system that is virtual water--agricultural water resource of the agricultural products. The system aimed to research space decomposition and differences between virtual water and agricultural water, at last according to the results of analysis, the corresponding opinions and measures for improving agricultural water efficiency can be proposed. The main research contents and conclusions are as follows:First of all, the paper systematically analyzed the basic concepts and features of the virtual water, as well as virtual water strategy, virtual water import and export, virtual water flow, virtual water balance, and three theoretical basis of the virtual water. According to the situation in our country, this paper introduced the application of the virtual water trade. Through determined the per-unit virtual water content of main crops in Sanjiang plain, all kinds of crops of virtual water content can be obtained, to analyze structural change of crops. Compared with China’s average crop virtual water content, the conclusion was that since2003virtual water volume of food crops raised a lot. This illustrated that the region had the universal advantage of water-saving planting. In view of these, the virtual water is new ideas to realize sustainable development of water resources, and plays an important role to change the water resources spatial pattern of uneven distribution.Secondly, under the base of the virtual water of the main agricultural products in1999-2009and15farms virtual water in2005-2009, using Theil coefficient, the paper decomposed space difference of agricultural products virtual water-agricultural water resource in three areas from2005to2009. Moreover a regional separation coefficient was also introduced to discuss convergence and divergence of the space distribution pattern. This paper used the ArcGIS software to make space difference decomposition results visualization, to more intuitively judge the relationship between virtual water and agricultural water of agricultural products, which aimed at revealing evolution characteristics of virtual water-agricultural water resources of agricultural products and time and space distribution characteristics of agricultural water behind the differences.According to space difference decomposition and research of virtual water-agricultural water resources of agricultural products, the concept of virtual water can be extended to adjust the agricultural water from the scope of grain application; the area of rich in water resource ought to produce water intensive products. Using virtual water theory, give full play to the advantages of each area, and adjust the planting structure, all of these are the effective way to realize the optimized configuration of agricultural water in the true sense. And according to geographical situation in Sanjiang plain, this paper proposed some measures such as the reasonable exploitation of groundwater and surface water, water resources optimization space utilization, adjusting agricultural planting structure and agronomic measures of improving agricultural water use efficiency and so on.Finally the paper summarized the main conclusion, pointed out the deficiency, and looked forward research orientation prospects.