Spatial gradient change of land use patterns in Qiandongnan Prefecture
The paper is inclined to present our study of the spatial gradient change of land use patterns in Qiandongnan (Southeast of Guizhou) Prefecture based on DEM data and remote sensing maps of the place in 1993, 1999 and 2009.In this paper, we have analyzed the land use structure and the changing trend at the diverse elevation gradients during the study periods.First of all, we have classified the whole land use data into five types, that is, the forest, the farmland, the grassland, the water and the building sites.Then, we have defined the elevation gradients into six grades.And, next, we have extracted each gradient from the whole land use pattern.And, finally, we have worked out different indices for analyzing the land use features in proportion, area retio matrixes, spatial variables of land use degree and their changes with the landscape pattem indexes.The resuits of our study indicate that all the land patterns exist at every gradient, while water resource only exists at the range of 0-1 600 m.While farmland remains the main land use type at the lower elevations, forest and grassland with some water areas and building areas are taking the place of the farmlands for the need of other uses.However, at higher elevations, forest remains the chief type of land use,with some amount of grassland, farmland, building areas turning into forests.And, furthermore, with the rising of sea-level, the spatial variation of land use degree declined, with more variations of land use augmented from 1993 to 2009 except for the areas of above 2 000 m for the natural forest protection program.From the standpoint of landscape, from 1993 to 2009, in the area of 0-1 200 m, the patch density has been declining drastically with spatial distributions more scattered.As to the elevation range of 1 200-2 000 m, the land use types have turned to be more complicated with more and more fragmentized and spatial distribution more aggregated.And, finally , in the range of 0-800 m and 1 600-2 000 m, a fluctuant change can be seen of the local landscape, though the range of 800-1 600 m and ＞ 2 000 m, looks more regular.
other disciplines of environmental science and technologyland usespatial gradientQiandongnan Prefecture
NETL
NSTL
万方数据
维普
