Analysis Of The Difference In Cultivated Land Quality Between Karst And Non-karst Areas

The cultivated land in the ecologically fragile karst region has its own regional characteristics.From the scale of the cultivated map,evaluate the quality of cultivated land,analyze the difference in cultivated land quality between karst and non-karst areas,and identify the main influencing factors of cultivated land quality to explore the cultivated land in the two landform types.The reason for the quality difference is of great significance to the protection of cultivated land according to local conditions in different landform types.This article takes Pingguo City,Guangxi as a research area,and uses the LESA system to comprehensively evaluate the quality of cultivated land from two aspects: the natural quality of the cultivated land and the site conditions.The differences in distribution;and the use of gray correlations to explore the correlation between the influencing factors and the quality of cultivated land in the city,identify the main factors affecting the quality of cultivated land,and analyze the reasons for the differences in cultivated land quality between karst and non-karst areas.The main conclusions are as follows:(1)Based on the nationally comparable natural quality condition system of farmland,"Agricultural Land Quality Grading Regulations",select 7 natural evaluation indexes of cultivated land,and determine the weight of each index accordingly,to build a natural quality evaluation system of cultivated land;according to frequency statistics Method,select 8 evaluation indexes of cultivated land site conditions,comprehensively determine the index weights by using analytic hierarchy process and entropy value method,and construct an evaluation system of cultivated land site conditions;finally build a comprehensive evaluation system of natural quality of cultivated land and site conditions,by calculating the cultivated land Correlation coefficient between the comprehensive quality evaluation score and the unit grain yield.The ratio between the natural quality evaluation system of cultivated land and the evaluation system of cultivated land conditions was determined to be3: 2,which indicates that compared with cultivated land conditions,the cultivated land productivity and cultivated land are natural.Quality matters more.(2)Based on the LESA system to evaluate the quality of arable land in Pingguo City,analyze the difference in the number of grades of arable land quality between karst and non-karst areas.The results show that the comprehensive quality of arable land in karst areas is good,medium and poor arable land accounts for 12.56%,85.22%,and 2.22% of the total arable land area in karst areas,respectively;non-karst arable land corresponding to the corresponding level of arable land comprehensive quality The total area of cultivated land in the district was 14.78%,83.79%,and 1.43%.Overall,the overall quality of arable land in karst areas is worse than in non-karst areas.Among them,the natural quality of arable land in karst areas is worse than in non-karst areas,and the conditions of cultivated land are better than in non-karst areas.(3)The Lorentz curve,Gini coefficient and landscape index were used to analyze the differences in the spatial distribution of cultivated land quality between karst and non-karst areas in Pingguo City.By plotting the Lorentz curve of the comprehensive quality of cultivated land in karst and non-karst areas,the results show that the Lorentz curve of the comprehensive quality of cultivated land in karst areas is farther from the absolute uniform line than in non-karst areas,and the Gini coefficient of the comprehensive quality of cultivated land is higher than that of non-karst areas.In areas,the comprehensive quality distribution of cultivated land in karst areas is more concentrated than in non-karst areas.Calculating the comprehensive quality diversity index,centralization index,dominance index and evenness index of cultivated land in karst and non-karst areas,the results show that the diversity index and centralization index show that the comprehensive quality grade of arable land in karst areas is more differentiated than non-karst The area is high,and the index of dominance shows that the comprehensive quality grade of arable land in the karst areas dominates the cultivated land resources in the area,and the evenness index shows that the distribution of the comprehensive quality grade of the arable land in the karst areas is more concentrated than that in the non-karst areas.(4)Use the grey correlation analysis method to analyze the correlation between each influencing factor and the quality of cultivated land to determine the main influencing factors of the quality of cultivated land.The results show that the five main factors influencing the qualityof cultivated land in karst and non-karst areas in Pingguo City are the thickness of cultivated layer,slope of cultivated land,continuous degree of cultivated land,susceptibility to geological disasters,distance from cultivated land to main roads,etc.Moreover,the conditions of these five main influencing factors in karst areas are all worse than those in non-karst areas,in order to analyze the reasons for the difference in the quality of cultivated land between karst and non-karst areas.