Spatial-temporal Analysis of Land Use Change in County Level Based on Remote Sensing

This paper takes Fengxian in Jiangsu Province as an example, on the basis of Landsat TM/ETM+ images of four different time(1988, 1995, 2001, 2006) and aerial photographs of 2005, meanwhile, auxiliary data such as administrative vector map of Fengxian, land use map and socio-economic statistical data of 1995,2006. supported by RS and GIS technology, land use spatial database and attribute database are established, then through ArcGIS9.0, land use structure change/quantity change, land use grade change and land use type conversion matrix analysis are analyzed on the basis of land use spatial database of four-temporal remote sensing. Based on four temporal Landsat TM/ETM+ images, the land use information of Fengxian, Jiangsu Province in 1988, 1995, 2001 and 2006 is extracted by the supervised classification and visual interpretation methods. Then, land use type dynamic change and transforming trend of land use type are analyzing quantitatively. The result shows that from 1988 to 2006, construction land and forest land are continuously increased, and unused land and arable land are sustainably decreased, water body is first increased and then decreased, on the contrary, orchard land is firstly reduced and then increased. At the same time, due to urbanization drive, part of arable land and forest land is occupied, in order to compensating for the loss, and driven by economic interests, the unused land within the whole county are constantly being developed, gradually consolidated into forest land, orchard land and arable land. The speed of area increase of construction land and reduction of arable land and unused land is perhaps accelerated, while the increase of forest land is small. in the view of the entire county, the land use change is not intense, but in local areas greater change of land use has taken place, in a word, the main characteristic of land use change is that arable land is largely transformed into construction land.