Studies On The Relationship Between City Wetland Dynamic Change And Distribution Of Thermal Field In Hangzhou

Be hailed as "Natural Air Conditioner", the city wetland has profound effect on improving city thermal environment, city landscape construction, natural species protection and strengthening flood control and drought resistance. However, for nearly30years with urbanization development, more and more wetland was occupied for city construction, which has serious impact on residents living standard and social public development.This article selected Hangzhou located in China southeast coast as research area. Based on researches at home and abroad about monitoring wetland dynamic changes, city land surface temperature and Relationship between City Wetland Dynamic Change and Distribution of Thermal Field, it studied the positive connection between City Wetland dynamic change and land surface temperature distribution in Hangzhou by applying TM/ETM remote sensing and geomatics technology. It also revealed the ecological significance of wetland in the city, and presented the measures and suggestions on protecting city wetland, remitting city heat island.Conclusions:1. The wetland dynamic changes research between1978-2010shows the wetland area decreased sharply260.06km2during the last32years, including constructed wetland249.75km2, marsh9.99km2; the space distribution of wetland changed a lot by shrinking100m per year toward surrounding areas. Only lake wetland area increased1.97km2, i.e. the West Lake extension project in2002added0.27km2of lake wetland.2. Combined with TM data preprocessing and contrast studies of Methods to inversion Land Surface Temperature, three Thermal field space distributions on May12,1994, October11,2000and May24,2010were obtained in this section by using mono-window algorithm. The results was proved dependable and it could meet further research of city thermal field distribution.3. The article studied the connection of city thermal field distribution and land surface types by using Thermal field grade analysis and Profile analysis, the result indicated the city wetland has apparent cooling effect on city heat island. Meantime, in order to protect city wetland and follow the sustainable path, the article put forward the protection measures and rational utilization of wetland. It illustrated from three prospective of optimizing city layout, controlling strictly city construction occupation and wetland protection legislation to supply a reference to the departments concerned.