苏锡常地区土地利用变化时空分异及其生态环境响应

以苏州、无锡和常州所辖市(区)为分析单元,揭示土地利用变化的时空分异特征,结合对该区域生态环境状况的评价,重点分析土地利用变化时空分异的生态环境响应。结果表明:1980~2000年苏锡常地区土地利用变化的主导类型是城乡建设用地大量扩张和耕地资源急剧减少,土地利用变化类型趋于多样化;土地利用结构存在不同程度的空间差异性,土地利用有序性和综合变化速度也具有明显的空间分异特征,土地利用系统趋向于复杂无序和加速演化;区域多数单元的生态环境状况不断变差,且对土地利用变化时空分异具有明显的响应特征;生态环境状况对土地利用有序性和综合变化速度的响应程度具有明显的区域差异性,而且这种响应和差异性程度都有所加强。

Spatio-temporal pattern of land use change and its eco-environmental response in Suzhou-Wuxi-Changzhou Region

The Suzhou-Wuxi-Changzhou(S-X-C)region is one of the hottest spots for socio-economic development in China, the land use change and corresponding eco-environmental problems have intensified further. Taking 12 county-level cities and districts of the region as study units, the spatio-temporal distribution characteristics were revealed and eco-environmental situation was evaluated, based on Landsat TM data in 1980, 1995, 2000 and relevant statistical and investigation data on eco-environment. Further, this paper mainly analyzes the eco-environmental responses to spatio-temporal distribution of land use change. Results of the study show: (1) The dominant types of land use change from 1980 to 2000 are the land expansion for urban onstruction purpose and sharp decrease of cultivated land. The conversion of paddy fields to urban and rural construction land dispersed in every unit. However, the conversion of other different land types relatively concentrated in several main units. And the number of dominant types of land use change more from was greater 1995 to 2000 than that 15 yearsago. (2) As an index used to measure land use diversity, Dj showed that there were different land use structure in every unit, and the diversity degree between every two units was different but the difference showed a tendency of decreasing. The information entropy of land use structure was used to weigh land use system orderliness. On the one hand, it showed that land use system tended to be more and more disordered in the majority of units, on the other hand, the disordered degree becomes gredter more obvious with the development of society and economy. In addition, the index V indicated the similar character of land use change rate with land use system orderliness. (3) Eco-environmental situation tended to deteriorate gradually in most units, especially in the recent five years (1995-2000). There were distinct and different eco-environmental responses to land use change and its spatio-temporal distribution. The phenomenon was more outstanding in the main units of land use change. (4)In different units, the eco-environmental status responded differently to the orderliness and comprehensive change rate of land use. Moreover, the response and its differentiation increased to different degrees with the change of land use. In general, the paper emphasizes the response of eco-environment to land use change and its spatio-temporal distribution characteristics. It puts forward suggestions concerning the adjustment of land use planning, industrial policy and the optimization of land use pattern and improvement of land use mode, on the basis of simulation and prediction of land use change and its possible eco-environmental response.