Estimation On Temporal-spatial Characteristics Of Anthropogenic Heat In Qinhuai District Of Nanjing Based On The Inventory Survey Method

With the rapid development of the economy,the process of urbanization is accelerating.The rapid expansion of urban population and the expansion of the urban scale caused rapid changes in the underlying surface and canopy structure,resulting in the rapid increase of anthropogenic heat emissions(AHE)in the city,and caused many impacts on urban heat island effect and the regional climate change.The intensified urban heat island effect not only affects people's learning,life and work,but also hinders the development of cities and the quality of human existence,and the important factor of urban heat island effect is anthropogenic heat emissions.Numerous studies showed that AHE significantly strengthened the urban heat island effect,which influenced urban and regional climate and air quality,and got feedback effects on social economic activities.In the past,due to the lack of estimation and research on anthropogenic heat emissions,most researches on urban heat island effect,regional thermal environment and other studies ignore this part of heat in the past flux.But in recent years,with the increase of urban energy consumption,anthropogenic heat emission has become an important factor which cannot be ignored in urban heat island effect.However,current studies and knowledge about anthropogenic heat emissions are relatively insufficient,which severely restricts the relevant studies.Therefore,it is of great significance to further study the estimation of temporal-spatial characteristics of anthropogenic heat emissions at small scale.Taking Qinhuai District of Nanjing city as the study area,the research divided anthropogenic heat into human metabolism heat,industrial heat,building heat and transportation heat.And the research established a relationship model of the three components of 'anthropogenic heat emissions,time(daytime and nighttime)and land use'with the help of GIS modeling and spatial analysis technology,which is applied to quantitatively estimate the anthropogenic heat emissions during the daytime and nighttime and to explore the temporal and spatial characteristics of different types of anthropogenic heat.In order to achieve above goals,based on the bottom-up energy inventory method and statistical data of population and energy consumption,the research used the remote sensing image with the high spatial resolution,combined with the field investigation to analyze its spatial distribution characteristics of different anthropogenic heat release sources at 100m grid scale.Finally,combined with the population density and regional economic growth indicators,the research preliminarily discussed the change trend of anthropogenic heat emission and urban development.The research provided a set of universal method for estimating regional anthropogenic heat emission and a new exploration for the research of temporal-spatial distribution of anthropogenic heat emissions in different scales.The main conclusions of the research include:(1)During the daytime,the total amount of AHE in Qinhuai district is 7.37×1013J,and the mean flux is 33.45W/m2.The contribution of commercial buildings is highest,with a percentage of 44.64%,followed by transportation,residential buildings,human metabolism and industry,respectively,25.78%,18.23%,10.69%and 0.66%.During the nighttime,the total amount of AHE in Qinhuai district is 3.38×1013J,and the mean flux is 15.34W/m2.The contribution of transportation is highest,with a percentage of 33.68%,followed by commercial buildings,residential buildings and human metabolism,respectively,28.47%,21.78%,14.63%.During the daytime,the largest heat intensity is commercial buildings,its heat intensity is 14.93W/m2,followed by transportation,residential buildings and human metabolism,respectively,8.63W/m2,6.10W/m2 and 3.58W/m2.The average heat flux of industry is smallest,with a value of 0.22W/m2.While during the nighttime,the transportation is the main source of anthropogenic heat,the average heat flux is 5.17W/m2,followed by commercial buildings,residential buildings and human metabolism,respectively,4.37W/m2,3.34W/m2,2.24W/m2.The industry heat(0.22W/m2)is still the lowest anthropogenic heat emission.(2)There spatial distribution of anthropogenic heat emission intensity is obvious during the daytime and nighttime.During the daytime,the high anthropogenic heat emission intensity is main distributed in the southwest of the study area,including Chaotiangong,Wulaocun and Hongwulu street,its spatial pattern is consistent with the commercial area divided by the urban road network.Besides,the anthropogenic heat emission intensity in most areas concentrated in 15-30W/m2.In some regions,its anthropogenic heat intensity can reach even more 100W/m2.The low emissions are located in Honghua and Guanghualu street.During the nighttime,the high anthropogenic heat emission is less,and the distribution of heat intensity is uniform,most areas is among 4-17W/m2.The high emissions main concentrated in the fast road network.(3)In the four anthropogenic heat sources,the spatial distribution of human metabolism is approximately the same as that of population in the study area during the day and night.During the daytime,the high emissions are mainly located in the northwest.However,human metabolism has no obvious high emission area,its mean emission intensity is 2.24W/m2.The average emission intensity of transportation is 8.63W/m2 during the daytime and 5.17W/m2 during the nighttime.Whether during the daytime or nighttime,the heat intensity of fast roads is maximum,followed by main roads,secondary roads.As the biggest anthropogenic heat emission source,the distribution of commercial buildings is similar to the spatial distribution of population during the daytime.The high emissions during the daytime and nighttime are both located in the northwest,but the mean heat intensity during the nighttime is much lower,about 4.37W/m2.The distribution of residential buildings is similar to the spatial distribution of population during the nighttime.During the daytime,the anthropogenic heat emission intensity of residential building is 6.10W/m2,While the value during the nighttime is relatively lower,about 3.34W/m2.The average heat intensity of industry is 0.22W/m2,but some regions can reach more than 91.28W/m2.