Land use changes and driving forces in Tai Lake regionfrom 1980 to 2005

Studies on land use changes are one of the current research hotspots in man-land relationship. In order to promote coordinate development of man-land relationship between regions around Tai Lake in Jiangsu Province (RTLJP), land use change information of RTLJP in 1980, 1990, 2000 and 2005 were extracted by integrating Landsat-TM/CBERS images with remote sense software. Based on statistic method in conjunction with GIS, characteristics of land utilization quantity changes and that of land use conversion in three periods (1980-1990, 1990-2000, 2000-2005) of RTLJP were revealed. Furthermore, driving forces of land use changes in three periods were discussed. The results showed that lots of land use types took place complicated changes and converted between each others for 25 years. Meanwhile, the spatial- temporal characteristics of land use changes were different in three different periods. From 1980 to 1990, paddy field, water area and forest land were the main land use types, and the conversion from paddy field, forest land to construction land, and from forest land, dry land to paddy field were the main types and accounted for 87.21% of all land use types conversion. From 1990 to 2000, paddy field, water area and construction land were the main land use types, and the conversion from paddy field to construction land, dry land, water land, and from forest land, water land to paddy field were the main types and accounted for 80.18% of all land use types conversion. From 2000 to 2005, construction land and paddy field were the main land use types, and the conversion from paddy field to construction land, water area, grass land, forest land, from water area to construction land, and from water area, forest land to paddy field were the main types and accounted for 87.00% of all land use types conversion Regional land use degree was enhanced year by year, and finally was increased from 265.1 of 1980 to 299.9 of 2005. Land use was still in developing period. According to the changes of land use types conversion from 1985 to 2005, the entering speed of construction land was much greater than the exiting speed, which had the trend of a scale increasing. In the meanwhile, the entering speed of paddy field, dry land and forest land were less than the exiting speed, and presented a scale reducing trend. Human activities including population growth, economic development produced by industrialization and urbanization and land management policy were the main driving forces of land use changes of RTLJP. From the above, we can see that although RTLJP obtained great economic benefit because of land development, it faced degradation of the cultivated land resources, which challenged its coordinative and sustainable development of man- land relationship. This study quantitative defined the characteristics of land use change and their driving forces, and finally put forward a scientific reference for sustainable utilization of land resource and harmonious development of man-land relationship.