Study On The Thermal Environment Characteristics Of Kunming

With the acceleration of urbanization,the types of land use and the properties of the underlying surface of the city have also changed significantly.However,in the urban planning stage,the planning and design of the urban environment,especially the outdoor thermal environment,is often considered less.This has brought a series of negative effects to the living environment.Therefore,on the basis of ensuring the comfort of the living environment,it is an important research topic to rationally plan the city,improve the urban thermal environment and promote the sustainable development of the city.The research scope of this paper focuses on Kunming,a low-latitude plateau mountain city.The World Urban Database Access Portal Tools(WUDAPT)method is used to obtain the local climate map of Kunming,and the local climate zone of Kunming.The type composition and changes were analyzed to propose improvements for the thermal environment in Kunming.Furthermore,the outdoor environmental parameters of a residential area in Chenggong District were tested in the field.The spatial distribution characteristics of temperature,relative humidity and wind speed in different test periods were analyzed.The relationship between the sky view factor and these three parameters was investigated.These work provides a basis for the improvement of the thermal environment in residential areas and has certain theoretical and practical significance.This paper mainly carried out the following work:Firstly,according to the perfect and versatile method of WUDAPT,the regional climate map of Kunming in 2008 and 2018 was constructed by SAGA GIS software through local climatic zone classification.The spatial distribution of different types of LCZ plaques in 2008 and 2018 was extracted.Combined with the urban “blue-green” ecosystem,the distribution of land cover and urban morphology evolution in the main urban area of Kunming were analyzed.The research results show that the type of built-up land in Kunming shows a distribution trend of the central city gathering and gradual divergence.The distribution of green spaces and water bodies is densely edged and sporadic downtown.Secondly,through quantitative and statistical analysis of plaques in local climate zones in Kunming and the five major urban districts,the proportion distribution and change of the local climate zone in urbanization of Kunming and five different urban areas are obtained.From 2008 to 2018,the main development trend of the built-up climate zone in Kunming is the opening of highrise buildings.The proportion of open high-rise buildings in the past ten years has increased by 16.97%.Combining the meteorological data of Xishan District,Panlong District and Chenggong District,thermal properties of the local climate zone were analyzed.The study shows that the large-scale increase of the built-up climate zone in Panlong District and Chenggong District and the reduction of green water in the urban area have contributed to the increase of temperature.The proportion of built-up climate zones in Xishan District is only 29.06%,far lower than that of Panlong District and Chenggong District.However,the average annual temperature in Xishan District has been higher than that in Panlong District.Finally,the field test of the thermal environment characteristics of a residential area in Chenggong District is carried out.The residential area of the open climatic zone was selected as the measured area,and the outdoor meteorological parameters,block morphological parameters and underlying surface materials were measured in the residential area.By plotting the contour maps of wind speed,temperature and relative humidity,combining with the relationship between the sky view factor(SVF)and these three meteorological parameters,the outdoor thermal environment characteristics of the residential area is analyzed.