Research On Pattern Of Rock Desertification Landscape In Xiang Xi, Hunan Base On RS, GIS And GPS

We can deeply research ecology environment effects in regions of landscape spatial dynamic changes by technology of RS, GIS and GPS combine with landscape ecology.Rocky desertification is one of serious entironmental questions in China.The analysis of landscape pattern is one of the fundamental research scopes in Landscape ecology. Presently, most landscape pattern research only describes its geometric feature. Aiming at a special ecological process, combining ecological process with landscape pattern is the development trend of landscape pattern research in the future. Landscape changes at all time, pattern change is one aspect of landscape dynamic.The landscape ecological structure and function and the essential features of landscape ecological procedure in karst mountains of Xiang Xi are analyzed in this paper, in order to understand the ecological spatial character and evolving procedure of karst mountains from landscape viewpoint. The changes of landscape pattern and landscape process are each other cause and effect. The spatial and temporal rule of landscape pattern change and which driven mechanical is the foundation of landscape pattern change research combining with ecological.This study characterized the dynamics of landscape patterns of rocky desertification at landscape scale in Xiang Xi area in Hunan province between 1977~1999 by using satellite remote sensing techniques.Landsat TM satellite images for 1977,1989 and 1999 were classified and analyzed. The results showed that the landscape areas of rocky desertification have been increased between1977~1989 and have been decreased between 1989~1999. By applying geographic information system(GIS), patch-related landscape indicis were generated and the spatial patterns of rocky desertification changes over 30-year period were analyzed.The research indicated that the landscape patterns of rocky desertification in Xiang Xi have been experienced a dynamic process from gradual change to strong change to gradual change. Denoted by the soil dynamic index,the evolved speed of the total landscape of rocky desertification in Xiang Xi area were mainly influenced by three styles,such as potentially degraded desertification,lightly degraded desertification and moderately degraded desertification.By quantifying landscape indices ,such as landscape dominance index, fractal dimension and patch density ,etc.,the landscape dominance index was lessed than 0.50 and the fractal dimension was closed to 1.The diverse types of rocky desertification landscape in Xiang Xi inclined to equality and the dymanic change of the shapes of landscape mosaics inclined to simplification.The total of patches and the patches density inclined to decrease.Moreover,the study discussed the driving machenism of dynamic change of rocky desertification and the eco-environment in Xiang Xi.The landscape patterns of rocky desertification were profundly influenced by human movements,especially on the strongly degraded desertification in Xiang Xi area.