无锡市城镇化进程中土地利用变化及其环境效应

20世纪90年代,城市用地扩展是我国区域土地利用演化的主导过程,城市土地利用所引起的地表景观格局的变化又是引起地表各种地理过程变化的主要原因。基于Landsat TM图像解译的土地利用的动态图斑,分析了20年代90年代无锡市土地利用的变化态势。研究表明,土地利用变化主要体现为耕地向林地、水域、建设用地的转移．林地向耕地、建设用地的转移,以及草地、水域向建设用地的转移;20世纪90年代中后期,国家颁布的一系列基本农田保护和“退耕还林还草”的政策法规,在一定程度上限制了大量耕地被建设占用的趋势。土地利用快速变化也导致明显环境效应．主要表现为水环境的恶化和现代“城市病”等方面。因此,加强土地规划管理、合理利用土地资源、重视能源开发与基础设施建设,应成为今后区域土地资源开发、利用与保护的重点与方向。

LAND-USE CHANGE AND ITS ENVIRONMENTAL IMPACT DURING URBANIZATION IN WUXI MUNICIPALITY

The expansion of man-made built-up areas is predominant in land use change at regional scale in China in 1990s. The landscape change resulted from the land use change, in some sense, is the main driving force for the modern geographical process. A study on the land use change and its environmental impact at regional scale is of significance for decision making on the optimized allocation and rational exploitation of land resources. Wuxi municipality, an axes of the Su (Suzhou)-Xi (Wuxi)-Chang (Changzhou) urban expansion belt, has been characterized with a rapid urban expansion since the reforming and opening policies were introduced in late 1970s, represented as the conspicuous expansion of built-up areas. Based on the dynamic patehes of land use change interpreted from Landsat TM images, the authors analyzed the characteristics of land use change of Wuxi municipality in 1990s. The general feature of land use change has been generalized in this paper. In 1990s, the conversions from farmland to forestland, water body, man-made built-up areas, from forestland to farmland and man-made built-up areas, form forestland to farmland and man-made built-up is predominant areas and from grassland and water body to man-made buil-up areas is predominant in land use change. In the middle of 1990s, a series of laws and regulations to protect basie farmland losing and conversion of farmland to forest land and grassland has been implemented, the trend of farmland occupation for built-up areas was to some extent prevented from increase in Wuxi municipality. Meanwhile, the land use change in Wuxi municipali-ty has led to the obvious environment effect. this paper has made an in-depth analyses on the environment impact of land use change in the change of water environment and the breaking-off of "urban illness". A series of measures and suggestions were proposed on the rational use of land resources, land-use planning, energy ex-ploitation and infrastructure construction for Wuxi municipality.