Cultivated Land Ouality Evaluation And Productivity Capacity Accounting Of Fuyang City

With the rapid development of China’s economy, society, and the rapid growth of the population, the decrease in amount and quality of the cultivated land has gradually become one of the most prominent contradictions. Protection of cultivated land quality is not only related to the food security of our country, but also has importance to China’s sustainable economic development, social stability, and protection of the ecological environment. Cultivated land quality evaluation can provide a scientific basis for achieving rational use of cultivated land, ensuring food security, socio-economic and environmental sustainability for the study area.The paper takes Fuyang City, Zhejiang province as the study area. First of all, cultivated land quality evaluation research is studied based on P-S-R model:extract the evaluation indicators from remote sensing image and acquire evaluation thematic maps; use the linear interpolation method grade indicators; use AHP method to determine the index weights; and use GIS spatial analysis methods make the cultivated land quality evaluation study. And then evaluate the cultivated land quality based on GIS as follows:select the evaluation index systems with reference to the national farmland fertility survey and quality evaluation of technical procedures;divide evaluation unit by superimposing soil type map and land use map; determine the weights by Delphi method and AHP method; make the cultivated land quality evaluation by fuzzy comprehensive evaluation model. Explore the feasibility, the pros and cons of the assessment based on RS by comparing the results obtained by these two methods. At last, productivity accounting is completed by the method of linear model, fuzzy clustering and GIS analysis, based on grading results of the cultivated land in Fuyang City. Meanwhile, zoning for optimal management is studied to explore the spatial difference of the study area, the soil management measures by the zoning results. The study results as follows:1. Get cultivated land quality evaluation results from three aspects of farmland production pressure, farmland status and comprehensive quality of cultivated land based on P-S-R model and RS technology. Select seven index of the slope, heavy metals index (HMI), degradation index (RVI), the soil vegetation index (NDVI), soil moisture index (DVI), soil fertility index (SFI), the type of land use index (LUI) to make the evaluation. The research separated the cultivated land into4ranks. The proportion of class1is21.65%, it has the best quality and mainly distributes in middle hilly area and valley plains. Class2, which proportion is34.44%, mainly distributes in middle hilly area and valley plains. Class3mainly distributes around the mountains and urban industrial land and the proportion is23.08%. Most class4which proportion is20.82%, distributes in the mountainous area.2. According to the methodology promulgated by the Ministry of Agriculture, evaluate the cultivated land quality by determining the evaluation unit, establishing the index system from the four aspects of the site conditions, chemical properties, physical properties and soil management, determining the weights by Delphi method and AHP method, using the method of fuzzy comprehensive evaluation. Comparing two kinds of assessment methods based on RS and GIS from the method, index and result, the comparing result showed that both evaluation results have consistent trend. Therefore, applying RS into assessment, the feasibility and the advantage is obvious:the RS technology not only could supply basic information, saving a lot of manpower, material and financial resources, but also be as a direct method to get indicator information; take the grid cells as the evaluation unit is not only fast and easy, but also improve the accuracy of evaluation.3. According to the quality of cultivated land grading results, the field survey sample point data and the yearbook data from statistical departments, by establishing different levels of capacity accounting model, estimate the theoretical productivity and realizable productivity of Fuyang City to have a comprehensive understanding of the amount and spatial distribution of cultivated land productivity. The results show that:Fuyang City realizable productivity is1.91times the actual capacity; total potential capacity of95,130.33tons. Therefore, there is a big upgrade and development potential capacity for Fuyang City. By fuzzy clustering analysis, get zoning result for optimal management based on productivity accounting. And according to the production management characteristics of each zone, the Fuyang City is divided into four management areas:enhancing core zone, optimization and developing zone, protection and developing zone, sustainable zone. Based on partition results, comparing the result of cultivated land quality evaluation based on RS and the result of zoning for optimal management, the comparing result further confirmed the feasibility of cultivated land quality evaluation based on RS.