Lossless Extraction And Expression Methods Of Cultivated Land Information Based On Multi-scale Grids

Cultivated land resource is one of the most important components of resources and environment.The nondestructive extraction and grid expression of cultivated land information are of great significance to the management of cultivated land resources.To meet the multi-scale land management needsand to solve the precision problem of the rule of Max Area gridding method rely on best scales,lossless extraction and expression of cultivated land information method based on multi-scale grids was put forward.Five different scale grids data:32m×32m,64m×64m,128m×128m,256m×256m,512m×512m were created based on 1:1 million landusedata of Ruicheng County of Shanxi Province.Using 32m × 32m basic grid data as information container,the nondestructive grid of cultivated land and soil nutrient information wereextracted.Through the extended development of ArcEngine,the rapid extraction of cultivated land information from multi-scale grid was realized,and a method to express the spatial distribution of cultivated land based on cultivated land grid purity index was put forward and a thematic map was made.The research results were tested by the error analysis method of cultivated land area and the elliptic model of standard deviation,and it showed that:Multi-scale farmland grids data error wasless than 0.1m,which realizes lossless grids expression;average center was less than 1m and distribution direction wasless than 0.1°,which shows that the spatial distribution of cultivated land resources is highly consistent with the original vector cultivated land data;compared with the spatial expression effects of the Rule of Max Area girdding method and purity index method on different scales in mountainous areas and plain,the multi-scale spatial distribution characteristics of cultivated land resources can be expressed quantitatively based on the expression of cultivated land purity index in different landforms.However,using RMA method in different landforms will result in the spatial distribution of cultivated land showing in a tendency of compression or extension,and the degree of compression or expansion varies with the scale of gridTherefore,the nondestructive extraction method of cultivated land information based on multi-scale grid in this paper can accurately extract cultivated land information,and the spatial expression method based on farmland purity index can accurately express the spatial distribution of cultivated land resources at different scales.The multi-scale data can provide accurate data support for detailed management of cultivated land resources.