Study on the Dynamic Changes in Rocky Desertification in Yunshun County Based on RS in Northwestern Hunan Province

摘要

Rocky desertification is a process of land degradation involving serious soil erosion,extensive exposure of basement rocks, drastic decrease in soil productivity, and the appearance of desert-like landscape. It is caused by irrational, intensive land use on a fragile karst geo-ecological environment and it has become one of the most serious environmental, social, and economic problems in the mountainous areas. The spatio-temporal evolution information is very important to combat rocky desertification effectively. Remote sensing has been shown to be a powerful tool in monitoring and assessing rocky desertification. This paper focuses on extracting rocky desertification dynamic changes information from Landsat TM (1987) and Landsat ETM (2000) images in Yunshun County, northwestern Hunan Province. In order to improve the classification accuracy and efficiency, a novel image segmentation method and object oriented image analysis method are introduced. The result indicates that from 1980s, moderate and intense rocky desertification in this area has augmented significantly, and the situation of rocky desertification is very serious.