A Study On Agricultural Structural Adjustment Under The Restriction Of Water Environment In Erhai Basin

With the growth of population and the development of social economy, the problem about water shortage and deterioration of its environment fetches out every day, which has become one of the important aspects of the restriction of social economy and sustainable development. Agriculture holds an important position in our country and the agricultural structure is closely related to allocation of resource, growth of income, development of rural and the quality and sustainability of water environment. How to reduce the production of pollution and optimize the structure of agricultural under the restriction of water environment, become the one of the important focus in the process to achieve sustainable social economic development. Therefore, establishing the agricultural adjustment model under the restriction of the water environment is the theoretical and actual research value for a country or district.Erhai lake is located in the Dali Autonomous Prefecture, the second largest lake in the Yunnan Province, with229.4km2lake area and28.8×108m3lake volume, has provided the water for living and agricultural production, adjusting the climate and so on. In this paper, At first, The author introduces the related theory of agricultural structure optimization, analyzes the current situation of the agricultural structure and water pollution status of Erhai lake basin, and points out the industrial structure and the coupling relationship between the water environment. Then, establish agricultural structure optimization model under the restriction of water environment and analyze the dynamic adjustment of agricultural structure is one of the core contents in this paper. Finally, propose the appropriate safeguard measures on the basis of research achievements.The main research results obtained in this article are as follows:In2010, Erhai lake burden N, P pollution load2591.3tons,173.8tons respectively, the non-point source pollution of agriculture is the most important factor, accounting for85%of the total load. According to conventional monitoring water quality results, in2010, the pollution of TN reached0.6mg/L average, been in the class Ⅲ water quality state for nine months, and the pollution of TP reached0.023mg/L average, been in the class Ⅲ water quality state for five months. What’s more, in the past20years time, the N、P pollution had increased the3to4times and the water quality had been in the state of deterioration overall though some fluctuation.The author determines the largest output of agricultural economic and the most optimization of agriculture industrial structure goals for the model. Then in water environment constraint, agricultural resources constraint, social needs constraint, economic growth constraint and non-negative constraints as constraint conditions to establish multi-objective optimization model. And analyze the dynamic adjustment results of agricultural structure in different time under three different scenarios design. After detailed analysis obtained the second growth scheme fits the actual development condition of Erhai lake basin. At one hand, control the pollution effectively; On the other hand, keep the stable growth of agricultural GDP in the three planning period.Finally, put forward several safeguards for the adjustment of agricultural structure in Erhai Lake basin:strengthen the agricultural infrastructure system, accelerate the transfer rights of land contract to optimize the allocation of land resources, build and improve the mechanism of ecological compensation agriculture gradually, promote the industrialized operation of agriculture and develop the economic cooperation group, improve the agricultural market and social service system, develop the training for the rural labor and establish the transfer mechanisms for the surplus labor, and so on.