Evaluation And Linkage Of Cultivated Land Quality For Different Geomorphic Regions And Scales

Land resource is the main source of human survival. Cultivated land is the most important of land resource, and its quantity and quality is an important aspect of the national security. Since 1990s, the pressure of water, soil and biology has been increasingly great. Land quality is paid more attention by all over the world, international organizations and scientists. Cultivated land resource is the basic of grain production, and it can provide spatial, material production and ecological service. Protection of cultivated land has important significance for guaranteeing nation grain safety, maintaining social stability, and promoting economic all-round, harmonious, sustainable development. The quality of cultivated land will directly affect agricultural sustainable development and grain security. Developing cultivated land quality evaluation, clarifying cultivated land quality and its influencing factors is important basis for quality management of cultivated land and rational use of land.According to the key technical problems of non-uniform evaluation index systems in different geomorphologic and different scale regions, using traditional methods of soil investigation and geographic information system technology, this paper studies on the index system and results of cultivated land quality evaluation, researches unification and connection between different geomorphologic regions. In the case of Leling County, we studies on the spatial variability of different nutrient index, analyzes the effects of evaluation results with different sampling number, establishes cultivated land quality evaluation index systems of different scales. Detail research results are as follows:1. Based on GIS, overlapping soil map and land-use map and getting evaluation units of cultivated land quality evaluation, we established respectively index systems of cultivated land quality evaluation in Chiping (plain) and Zhangqiu County (hill). Using analytic hierarchy process and fuzzy mathematics method, we evaluated cultivated land quality and analyzed results of evaluation.2. Respectively analyzed results of evaluation with different index system in Chiping and Zhangqiu County, and established linear model that may link plain and hill index system. Using grey correlation, regression analysis and analytic hierarchy process, we analyzed plain and hill index system, selected important influence factors, and established uniform index system of cultivated land quality evaluation. Results of evaluation with uniform index system and its original index system are accordant through test. Uniform index system eliminates difference of different index system and realizes the uniform results of cultivated land quality evaluation.3. Using geo-statistics and kriging interpolation, analyzing data of sample point, we educed spatial variability character of soil nutrient index, and made certain rational number of sampling points.4. Analyzing results of cultivated land quality evaluation with different sampling scale, we determined the rational sampling scale.5. Based on the cultivated land quality evaluation of county level, according to spatial variability character of soil nutrient and other factors, we selected evaluation index of city level and provincial level, and established index system of cultivated land quality evaluation of different scales.6. In the case of Chiping and Zhangqiu County, we analyzed the results of cultivated land quality evaluation with different scale index system and approved the accordance of the results.