Analysis Of The Characteristics Of Local Environmental Temperature Effect In Nanjin

With the continuous development of urbanization,changes in urban morphology have led to significant changes in the local thermal environment and microclimate in cities,with significant differences in local ambient temperatures.In this thesis,the local climate zoning system is applied to Nanjing,and the local climate zoning map of Nanjing is drawn.Combining with the daily timing data observed by automatic meteorological stations in Nanjing,the intensity of the local environmental temperature effect in the city is used as an indicator to study the characteristics of the local environmental temperature effect in the city from two perspectives: local environment and observation data.The following conclusions are obtained:(1)Combining Landsat satellite imagery,real-world photos and field surveys,as well as the values of surface physical characteristics parameters,a local climate zoning map of Nanjing was constructed using the World Urban Database and Access Portal Tool based on remote sensing imagery,and quality assessment was performed using confusion matrix with an overall accuracy of 83.6% and a high degree of accuracy.(2)Starting from the perspective of local environment,under different time scales,the average overall local environmental temperature effect intensity in Nanjing city shows a slowly increasing trend from 2006 to 2020.The order of local ambient temperature effect intensity among building types is open high-rise LCZ 4>open low-rise LCZ 6>scattered buildings LCZ 9,and the local ambient temperature effect intensity at night in various regions is higher than that during the day,with stronger in spring and autumn and the weakest in winter.Among land cover types,dense forest LCZ A has a cooling effect throughout the day,and the intensity of temperature effect during the day is significantly higher than at night.It is strongest in summer and autumn,and even presents a warming effect during the day in spring;Low vegetation LCZ D has a warming effect throughout the day,and the intensity of local urban ambient temperature effect is significantly higher at night than during the day,especially in summer;The cooling effect of water body LCZ G during the daytime is significant in spring and autumn,while the warming effect at night is mainly reflected in other times.The smallest difference in the intensity of temperature effects in various types of regions occurs at noon,and the largest difference occurs around20:00 at night.Under different weather conditions,the order of urban local ambient temperature effect intensity is: sunny day>cloudy day>rainy day.(3)Starting from the perspective of observational data,the stations are divided into four categories according to the different characteristics of the daily variation of urban local environmental temperature effects: Category 1: low throughout the day,Category 2: high throughout the day,Category 3: low during the night,high during the day,and Category 4:high during the night,sometimes low during the day.Based on the results of local climate zoning,the corresponding relationship between different temperature effect characteristics and local environment was analyzed.The corresponding relationship between temperature effect characteristic type 1 and local environment type LCZ A is relatively significant.Temperature effect characteristic types 2,3,and 4 have certain corresponding relationships with various local environment types,but the corresponding relationships between various warming effects and specific local environments are relatively complex,and further exploration is needed.