GIS-Based Evaluating and Analysis for Farmland Fertility of Men-hai County

Through using the ArcGIS software as the platform, and taking DEM analysis, raster calculation and spatial interpolation of spatial analysis technology as the core method, this paper selects Menghai County as the study area, combines with the Delphi method, analytic hierarchy process, fuzzy membership function, farmland Integrated Fertility Index ( IFI ) and other methods, to establish major factors of influence and their weights for the farmland land productivity, as well as built a comprehensive evaluation system and it´s spatial computing model. Meanwhile, the analysis such as spatial distribution, area statistics and farmland nutrient analysis for the evaluating results is also discussed in detail. The experimental results and analysis show that, 51575.73 hectares of cultivated land in Menghai County is divided into six grades, which percentages on the total farmland from grade one to grade six respectively are 14.12%, 27.4%, 20.17%, 17.23%, 12.70% and 8.38%, and the level over three grade of cultivated land occupies only less than 60%. As a result, it could be declared that the overall situation of cultivated land fertility is not good, which needs the government to adjust measures to local conditions to maintain the existing quality of cultivated land resources, as well as to enhance the farming ability of cultivated land from level of grade 3, especially grade 4 and 5 to higher level.