| Water and land resources carrying capacity is material foundation for human survival and development as well as an important part of food security. At the same time, water and land resources sis limited, valuabe resource which can't be substituted. With population growth, economic development and the urbanization process, the demand for living water and land is increasing, and non-agricultural industries will occupay more and more agricultural water and land resource. As shortage of agricultural water and land resources, constraints on the regional agricultural development has become increasingly prominent. How to ease, coordinate and handle the increasingly prominent contradiction between the water and land resources, population, economic development, agricultural production has become a serious problem. Agricultural water and land resources carrying capacity is the premise that agricultural land and water resources efficiently and sustainably use, is also the key to regional social and economic sustainable development. Sustainable and efficient use of agricultural land and water resources must be within the allowable range of resources carrying capacity. Therefore, to solve these problems and contradictions, analysis on agriculture water and land resources carrying capacity is necessaryBeginning with the relationship between water and land resources, population, environment, economic development, and agricultural production, and combining with the research results of scholars at home and abroad, the paper analyzes the connotation, characteristics and influence factors of agricultural water and land resources carrying capacity. On this basis, author applies the principles and methods of system dynamics, and establish simulation model of water and land resources carrying capacity of regional agriculture, and then test the model. The results show that the model structure and behavior is consistent with the actual system, and the model has a good reliability. For the utilization status of agricultural water and land resources and socio-economic characteristics in Sichuan province, author applies the system dynamics model of water and land resources carrying capacity of the regional agriculture. The paper carried out empirical study on agricultural water and land resources carrying capacity under three different nutrient levels in Sichuan province, and the results are analyzed and summarized.The main conclusions are as follows:(1)Along with economic development and the acceleration of urbanization, the demand for construction land, transportation land , water conservancy facilities and returning farmland to forest and grassland will continue to increase, and the arable land will decline. According to forecasts, the arable land will be respectively reduced to 88.47 million mu in 2020, and 87.39 million mu in 2030.(2)The total water consumption will increase, and the contradiction between water supply and demand will be highlighted in the future. Industrial water consumption will respectively increase to 7.282 billion m3 in 2020, and 8.568 billion m3 in 2030. At the same time, the living water consumption will respectively reach 3.454 billion m3 in 2020, and 3.729 billion m3 in 2030(3)Agricultural production still has a greater potential. According to forecasts, food production potential will be 39.9 million tons in 2020, and 40.7 million tons in 2030, compared with the actual output of 32.111 million tons in 2005.(4)To achieve the desired output, total fertilizer demand will be 2.22 million tons in 2020, and 2.54 million tons in 2030.(5)According to the model simulation, in 2020, agriculture resources carrying capacity under three different nutrition level respectively is 146.99 million people in subsistence, 121.78 million people in the comfortable level and 94.47 million people in the nutrition and science level. In 2030, agriculture resources carrying capacity under three different nutrition level respectively is 153.65 million people, 127.26 million people and 10676 million people. |
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