Study on Conversion of Cropland to Forest and Grassland in Zhaluteqi

By the aid of GIS and RS, the data of land use, slope class, land desertification and land suitabilitywere gained from several kinds of data. Each kind of data was analyzedand also the correlationof dry cropland with slope class, desertification land and land suitabilitywas studied. The area, distribution and its use types of suitablefor returning to forest or grass land from dry crop land were obtained.The conclusions as follows: the dry crop land is the largest part of crop land in Zhaluteqi and is the main land for conversing to forest and grass land. 0.14 percent of dry crop land is such the land that the slope is more than 15o , the desertification crop land is 9.68 percent, and large part of dry crop land is not suitable for cultivated but suitable for forest or grass, the degree of suitabilityfor crop is much low in the tatal suitabilityland. The area of dry crop land should be converted to forest and grass is 14661 hm 2, account for 5.34 percent of all dry crop land. Among the converting dry crop land, the area convertingto forest is 5635 hm 2, and the area converting to grass land is 9026 hm 2. The dry crop land converting to forest and grass land mainly distributed in the south of Zhaluteqi.