干旱区生态环境知识资源中心

The combined use of satellite remote sensing and geographic information systems (GIS) hits become one of the important tools to study land-use change. In an effort to halt desertification China hits launched it series of land conservation programs. The human activities have significantly changed the distribution and allocation of land resources in the Yulin prefecture over the last decade due to rehabilitation measures. In this paper, landscape evolution was investigated by two methods: (a) the transition matrix of land use was calculated with the help of the GIS soft-ware, Arc/Info; (b) changes of landscape metrics were analyzed using the landscape structure analysis program FRAGSTATS. Our objectives were to determine landuse transition rates among land-use types in Yulin prefecture over 14 years from 1986-2000 and to quantify the changes of various landscape metrics. Significant changes in agricultural landscape occurred within the area. The results show the significant decrease in barren land mainly due to conversion to grassland. The landscape has become more continuous, clumped and more homogeneous. The area's severe desertification has improved through the measures to combat it. This ecosystem still manages the high rates of utilization. However, the increased evapotranspiration and discharge of ground water are bothersome.