Study On The Optimization Scheme Of Local Climate Zone Layout Based On Multivariate Spatial Data

Urbanization and climate change are two important trends that will influence global development in the coming decades.One significant impact of urbanization is the urban heat island effect,which is also a tangible manifestation of climate change.Finding a balance between urban expansion and the quality of the urban thermal environment is crucial for ensuring sustainable urban development.This article focuses on mitigating the urban heat island effect by optimizing the layout of Local Climate Zones(LCZs)in four districts of Lanzhou City: Chengguan,Qilihe,Xigu,and Anning.Multiple data sources such as Landsat-8 OLI imagery,Luojia-1 nighttime light images,and building vector data are used to derive land surface temperature,classify LCZs,and extract human settlement areas.Based on the construction of the Urban Heat Island Intensity Index(UHIA),the thermal environment characteristics of different LCZs within human settlement areas are analyzed.At a macro scale,an optimal LCZ layout model is proposed based on certain population and settlement size limitations.At a micro scale,this study provides references for the rational allocation of urban landscapes with cooling effects based on quantitative analysis results.The main conclusions are as follows:1.The average urban heat island intensity(UHI)within human settlement areas is 2.295 ℃,significantly higher than the overall average of 0.729 ℃ for the entire study area,indicating a pronounced urban heat island effect.Different LCZs exhibit varying average urban heat island intensities(UHIA),with built-up LCZs showing higher UHIA than natural LCZs,mid-rise and low-rise building LCZs higher than high-rise building LCZs,and compact building LCZs higher than open and sparse building LCZs.2.Given the current population size and residential area,the optimal combination of LCZs for the urban thermal environment within human settlement areas is LCZ＿8 + LCZ＿7 + LCZ＿4 + LCZ＿1 +(LCZ＿10 + LCZ＿A-D + LCZ＿E +LCZ＿G).The optimization results reduce UHIA from 2.295 ℃ to 1.042 ℃,achieving a reduction of 54.58% compared to before optimization,indicating a significant macro-level optimization effect.3.The spatial distribution of urban water bodies significantly influences land surface temperature,and the impact of urban water body distribution on land surface temperature varies among different land use types.Planning LCZ＿1 and LCZ＿7 in areas surrounding urban water bodies can maximize the utilization of water cooling effects.The cooling effect of urban green spaces is heavily influenced by the green space area,with a significant temperature reduction only achievable with a certain scale of urban greenery.4.Urban morphology also has an impact on the thermal balance of urban land surfaces.To leverage the shading effect of high-rise buildings on solar radiation,when planning LCZs of the same type,increasing the variation in building height and reducing the sky view factor(SVF)within the region can be considered.Additionally,for Lanzhou City,the temperature difference between the city center and the urban periphery is not significant,so there is no need to excessively consider the distance from the city center in urban planning.