Study of Dynamics of Land-Use in Bajiang Basin Based on the Data of TM and ETM+

Abstract: According to basic problems with the construction of environmental resource supported conditions of social-economic sustainable development in the source area of water of a karst plateau, the land use /land cover pattern of Bajiang Basin has been researched. Using RS & GIS technology as a basic platform, we, analyzed the changes in areas of land-use and the features of spatial variation with access by information technology, space analysis technology and statistics, then performed spatial overlay operations to the land-use maps of different periods. On the basis of the situation of conversion between different types of land-use, we established a transition probability matrix for different land-use types of the river basin, so as to make clear the main types and direction of land-use changes in the Bajiang Basin. Through these, the conclusions were that the main land use types were croplands and woodlands which accounted for more than 79% of the total land areas; croplands, woodlands, bare lands and grasslands were the land-use types which varied most significantly within the river basin in the last 10 years. While cropland , residential and industrial land, land used for roads and unused land showed a marked increase, woodlands went in the opposite direction. This reflects the fact that the urbanization progress of the watershed has been accelerated but the condition of the ecological environment has been worsened; the changes in different types of land use were mainly effected by human activities and local policy. A large number of bare gravel, rocky desertification areas had a tendency to decrease, but not obviously. Thu , a scientific plan for land use in karst areas, and exploration of new technology and methods for the management of degrading karst or rocky desertification areas, will play a major role both in improving the eco-environment and in economic development.