Study On The Water And Land Resources Carrying Capacity In Yan’an

Yan’an has the problem of drought, water shortage and serious soil erosion.With the rapid economic development, water and land resources are confronted with a problem of supply and demand contradiction. Water and land resources for development of the regional economic which is called social "non-carrying" as well as water and land resources face uncoordinated matching. All above are bound to affect the sustainable development of economy and society in Yan’an. Therefore, this article are aimed at the purpose of assuring sustainable and efficient use in water and land resources, keeping coordinated development of socio-economic and ecological in Yan’an. This article studied carrying capacity of water and land resources and established water resources carrying capacity evaluation index system suitable for water Lacking Area in Loess Plateau. It also analyzed the main factors that affect carrying capacity ofwater and land resources in Yan’an. On this basis, rational development and utilization mode of water and land resources in Yan’an was explored in order to provide theoretical support and policy guidance forefficient utilization of water and land resources and sustainable development between socio-economy and ecology in Yan’an.The main contents and results are as follows:1、Analyzed the matching pattern of water and land resources space in Yan’an.Based on water, soil composition and changes in resources over the years in Yan’an, the regional water and land resources matching calculation modelwas built to match the utilization of water resources and the land resources, as well as the matching coefficients and divide matching attainment of water and land resources in Yan’an were calculated. Water and land resources in Yan’an showed a poor matching as a whole. Matching coefficient is only 3470m3/hm2, which was lower than the national average(5600m3/hm2) and showed large differences in the county.From a general view it showed a pattern of “high in the south, lower in the north, lowest in the middle”.2、Established carrying capacity evaluation index system ofwater and land resources in water lacking area ofLoess Plateau.In the analysis of the impact ofcarrying capacityof water and land resources in Yan’an, and combined with foreign research results in carrying capacity evaluation index of water and land resources, this paper elected 29 indicators of water and land resources systems, social systems, economic systems and ecological systems, built carrying capacity evaluation index system of water and land resources in water lacking area of Loess Plateau.3、Comprehensive evaluation of the carrying capacity of water and land resources was made in Yan’an.On the basis of constructing the evaluation index system and evaluation grade standard, this paper used PSO Projection Pursuit Model to evaluate carrying capacity of water and land resources in Yan’an. Then found out carrying grade of water and land resources in each county and compared with the calculationresults of gray relation projection method based on Principal Component Analysis, which increased reliability of the calculation results. The results show that: Huanglong County is in Class II, water and land resources are in a weak stress-free state and water and land resources satisfy rapid socio-economic development; Zichang County and Yanchang County is in Class IV,whose state of oil and water resources and balanced development of socio-economic is destroyed, and have big external pressure and their systems is unstable.Rest of counties belong to level III,whose systemsare stable belong to a sustainable state,as well as water and land resources and socio-economicof such countieshave coordinated developed.4、Studied barriers on carrying capacity of water and land resources and rational development and utilization mode in Yan’an.On the basis of calculating the carrying capacity, some concepts were introduced such as: "deviation index", "index contribution" and "obstacle degree". Then obtained the main limiting factors which affect carrying capacity of water and land resources, water resources development and utilization, water modulus, unit of arable agricultural output,unit consumption of production GDP and irrigation rate on cultivated land.Finally, arational mode fordevelopment and utilization of water and land resources was proposed in order to provide a policy support on sustainable and efficient use of water and land resources.