In order to understand the characteristics of Boundarv layer climate of the city of Xian,a svnthetic field observation on the boundary layer and the soil layer was carried Out from Oct.to Nov,in the Xian region,and several usefuI turbulence and radiation data are obtained.A two-Dimensional dynamical and thermal numerical model used in PBL structure of the city,The turbulence colosure is based on the turbulent energy equation;the soil properties and radiative properties are also considered in the model.The simulating results from the model are suitable to illustrate the situation of the Xian heat lsland by using field data.The result of calculations shows the existance of urban heat island which is several degrees higher in temperature than adjacent rural regions.The result also compares the importance of different factors such as artifical heat release,soil properties and the surface roughness.The total amount of fuel consumed in the Xian industrial area and its increase rate in recent yearsvhave been carefully studied.The predicted tendency seems good in compared with teh climatic analyses, which indicates that the urban-rural temperature difference in the year of 2000 is about 0.6℃ morethan that of the mowadays.
