都市土地使用變遷對自然環境衝擊之空間影響分析

The change of land-use in the city is unavoidable during the process for urban development. Most land utilization changes will produce negative impacts to the natural environment, especially to surface temperature, run-off and urban habitat which are easily affected by local factors. Although many case studies have already discussed about the impact to the natural environment for urban land-use in the past, most have focused on single environmental index rather than the comprehensive impacts. Meanwhile, possibly owing to the lack of more detailed and identical information of land-use change, most studies failed to explain spatial analysis more deeply and to master the spatial characteristics of the environmental impacts. Therefore, in order to understand the spatial impact characteristics of land-use change heat island effects, run-off and habitat diversity more thoroughly, this study not only developed a comprehensive study structure based on GIS techniques, but also established suitable indictors and estimation approaches for evaluating environmental performance and analyzing its characteristic and relation of the space according to relevant documents. This study first surveyed the land-use data in Tainan City and created a relevant geographical information database according to the classification standards of Taiwan Area National Land Use Survey. The study then compared the current database with the one established in 1994, analyzed the land-use change and the characteristics of environmental impacts. The result shows that the characteristics of environmental impacts can be divided into six clusters, and all three environmental impacts including surface temperature, run-off and urban habitat affect the city center area seriously. With the distance farther from the city center, the surface temperature change increases and the amount of run-off decreases. Such results indicate that the urban expansion has occurred and that the habitat diversity has higher values in areas with the practice of policies or ordinances.