Sensitivity Test of Impact of Urbanization and Anthropogenic Heat on Meteorological Elements in Xi’an

Abstract

Taking into account different anthropogenic heat( AH) sources from manufactories,vehicles and residents,we estimated the anthropogenic heat flux( AHF) in Xi'an,firstly,including energy consumptions by industry and residents,amounts of vehicles,traffic volumes of the main roads,etc. The estimated AHF was consistent with the urban development. Then we carried out a sensitivity test about AHF using WRF / UCM model,including anthropogenic heat( AH) with diurnal variation. The results are as follows:( 1)The WRF / UCM model could better characterize precipitation distribution in detail. AH effect could improve the simulation of temperature distribution and intensity,which could also make the urban ground flow field and precipitation distribution and intensity more close to the reality.( 2) Urban buildings could intercept long-wave radiation energy,AH also enhanced the strength of long-wave radiation energy and enlarged surface upward sensible heat flux.( 3) AH effect on the increase the boundary layer height was more obvious,with an average value of 50 to 100 meters. It was concluded that the sensitivity test about AH flux by using WRF / UCM model could increase the downstream vertical velocity,strengthen the local vertical circulation and decrease convective horizontal scale. With the fine land-use data and AHF,the vertical structure of atmosphere had changed,which resulted in rainfall intensity in different parts of the city.