Analysis And Optimization Of Potential Ecological Networks Which Can Relieve The Heat Island Effect

Urban thermal environment is an important indicator for urban ecological environment. The urban heat island is growing intensityalong with the process of urbanization.Green landscape pattern is an important factor in urban heat island, improving green connectivity, building green ecological network could make an important impact for heat island.This papertaking a rapid development city-Shenzhen as an example, putting the landscape ecologytheory into the research of heat island effect.Starting from the ecological function of relieving heat island effect, using the minimum cost model to explore the relationship between landscape connectivity and surface temperature. Selectingthe "source" plaques which couldmake a high contributionfor relieving the heat island. While taking the land use typesas resistance surface in the cost distance model, putting the landscape pattern indexrelated to the surface temperature and the types of land use as the basis ofresistance surface value assignment to generate the ecological network in the study area. To optimize the pattern of current situations of green space combining the green space system planning of Shenzhen. The main results and conclusions are as follows:(1)Basing on the connectivity analysis of plaques with different levels that of important dominant negative correlation with surface temperature. The higher importance level of plaques, the lower the average temperature of surface, The correlation coefficient as high as 0.977; The average surface temperature of different types of green connectivityfrom high to low in the order is plaque> branch> bridge district> loop> edge> porosity> core area, the average surface temperature of the core area isthe lowest.(2) The surface temperature of different types of land usehas significant difference, the surface temperature of natural green land types is lower thanthat of built-up areas 1-2℃. The relationship between the landscape shape index, patch size, aggregation index and surface temperature was higher.(3) Based on the distance model to generatethe ecological network which could relieve the heat island effect, showing that there is no problem for the overall planning of green space landscape patterncombined with the green space system planning. According to the status quo of green land coverand the relationship between the planning of green space, corridors can be divided into three categories which include conservation, improvement and reconstructionamong the 77 corridors. The pattern between improvement corridors andhuge ecological corridor planning ofgreen spaceplanningshowed consistency.Reconstructioncorridors connect the regional planning of green space and ecological corridors effectively, help to improve the connectivity between the green spaces. On the construction of minimal paths, it should according to the situation of land use in the study area, design a few small patches around the ecological nodes. To form the green structure of the network through the construction of the ecological nodes and the minimum cost paths, so as to reduce heat island effect.