Assessment And Optimization Strategy Research On Urban Cool Island Effect Of Chang-Zhu-Tan Green Heart Area Based On In VEST Model

With the accelerated development of urbanization,many environmental and climate problems have arisen in cities.Among them,urban heat island effect is one of the most obvious and far-reaching climate problems.As the ecological barrier and the leading area for ecological civilization construction in the Changsha-Zhuzhou-Xiangtan urban agglomeration,the urban ecological green heart zone is representative of inland climate.As the green heart zone of a large urban agglomeration,studying the relationship between its cold island effect and landscape pattern change not only clarifies the factors influencing the cold island effect of urban green heart,their spatial distribution patterns but also has guiding significance for the planning and construction of suburban green heart areas and green ecological areas.In this paper,we first analyzed the changes in the cold island effect of the Changsha-Zhuzhou-Xiangtan green heart area.Using the In VEST urban cooling model,we analyzed the changes in the cold island effect index of the Changsha-Zhuzhou-Xiangtan green heart area in 2000,2010,and 2020.Secondly,we further analyzed the spatial and temporal changes in the landscape pattern of the Changsha-Zhuzhou-Xiangtan green heart area.Using Fragstats 4.2,we analyzed and calculated five types of landscape pattern indices to obtain changes in dominance,heterogeneity,fragmentation,landscape aggregation,and connectivity of the forest landscape in the Changsha-Zhuzhou-Xiangtan green heart area.Furthermore,the Pearson correlation coefficient function in SPSS 25 was used to analyze the correlation between the changes in the urban heat island effect index and the landscape pattern index data in the Green Heart Area,in order to propose green optimization strategies for the Green Heart Area’s green space cooling effect.This study aims to provide a theoretical basis and methodological support for improving and optimizing the green space system planning of the Green Heart Area towards high cooling efficiency.Based on the above research analysis,the main results of this study are as follows:(1)The level of the urban heat island effect in the Changsha-Zhuzhou-Xiangtan Ecological Green Heart Area has continuously decreased from 2000 to 2010 and 2020.(2)The data from 2000,2010,and 2020 show that the forest landscape patch type area(CA),landscape area ratio(PLAND),and landscape aggregation index(AI)have continued to increase,while the number of patches(NP)and patch density(PD)have continued to decrease.(3)The heat mitigation index is negatively correlated with the forest landscape patch type area(CA)and forest landscape area ratio(PLAND),and positively correlated with the forest landscape patch number(NP),forest patch density(PD),but not significantly correlated with the forest landscape aggregation index(AI).In summary,the green space optimization strategies for the Changsha-Zhuzhou-Xiangtan Ecological Green Heart Area to mitigate the urban heat island effect are as follows:increasing small green spaces in available spaces,efficient organization,improving the diversity of green spaces,controlling the size of green patches,and improving the quality of green spaces.