Study On Land Use And Landscape Pattern And Function In Wuxi City

According to the TM/ETM remote sensing images of three stages, the land-use and langd-cover changes at different spatial & time scale and the driving force of those changes have been investigated in Wuxi city around Taihu lake. The characters of landscape pattern changes during 1991~2006 were studied by means of FRAGSTATS calculation method. Some impacts on environmental benefits were analyzed comprehensively. Some main results are described as follows:(1)The land use had changed greatly from 1991 to 2006 in Wuxi district. Forest land and agricultural land areas decreased largely in 15 years, but construction land and corner land increased during the period, and water land reduced slightly. The land-use change srate of Wuxi is high, especially after 2001, the dynamic degree in this period is twice that in previous years. According to the annual change ratio of land use, forest land is the fastest decreasing land, the second is agricultural land, construction land and corner land are the fastest increasing land. Socio-economic factors play a dominant role in the land use change in Wuxi City during 15 years, including population growth, economic development and the development of agriculture and so on.(2) The basic land use and landscape patterns in Wuxi city belongs to single large patchs. Human activities have great impacts on the area, farming large patche fragmentation, thus increasing the number of different landscape types. It also makes the area of different land use types decreased, resulting in an increase of landscape diversity and the reduction.of landscape dominance.(3) The relationship was analyzed between the landscape pattern change and the water pollution in Taihu lake.The destruction of waterbodies and wetlands reduced the purification capacity of water bodies. Agricultural land and construction land increased pollutant emissions. The destruction of forest land and the increase of fragmentation degree lead to a buffering ability reduction to the pollution. All those are important reasons for the deterioration of water quality.