Abstract:Land use and land cover change (LUCC) significantly influence regional climate as a critical aspect in the land-atmosphere interaction system. Cities and their surrounding regions tend to experience more intensive LUCC due to the high population and human activities. And the accelerating LUCC and urbanization has become an important factor which affect regional even global temperature change. In some developed countries, the space expansion rate and population growth rate all are low level. However, from the point of view of a long time (decades) and worldwide, the processes of urbanization are sustainably increasing observably. As a developing country, China is undergoing rapid urbanization, which is characterized by not only the extension of urban economy and population but also the expansion of urban land (urban sprawl). Urban sprawl is often presented by the conversion from original natural underlying surface to artificial architectural landscape land. Comparing with some developed countries (such as the United States) which have higher urbanization level but lower urban sprawl rate due to lower population growth rate, China is experiencing an urban sprawl process with high area ratios and magnitudes. The change process will have profound impacts on regional climate, revealed by the urban heat island (UHI) effect. Different land use types have different biophysical characters and processes, the emission of greenhouse gases only is one factor of the climatic change, the differences of surface radiation, energy and kinetic energy will directly or indirectly affect the near-surface energy balance, the local micro-meteorological conditions, the urban canopy layer, the atmospheric boundary layer and atmospheric circulation in urban and suburban areas, and affect the regional temperature changes finally. In this study, WRF/UCM (Weather Research and Forecasting Model/Urban Canopy Model), a meso-scale atmospheric model, which couple with an urban canopy model, was used to simulate the differences of near surface air temperature according to the different underlying surfaces, namely the land use/land cover types of 1970s and 2008 in Beijing-Tianjin-Tangshan region were used to replace the land cover data recommended by WRF itself. All the process were based on the meteorological field of 2008 and the other conditions all were the same. In the process, ANUSPLIN method was used to get interpolation data of observed temperature collected by 26 meteorological stations in the study area and its surrounding area. The study results showed that: WRF/UCM performed well on simulating the air temperature, both in the temporal or spatial scale. Almost all of the land use type transformations presented warming trend because the LUCC was dominant by urban sprawl in the area. And the warming extent over 0.05 ℃ in most of the study area. The largest warming region appeared in the urban expansion regions, up to 1.31 ℃. The entirety warming extent of the study area led by LUCC was 0.08 ℃, indicating that the warming contribution ratio of LUCC was 9.88%. Meanwhile, the warming extent of the urban expansion regions was 0.29 ℃, showing that the warming contribution ratio caused by urban sprawl up to 32.75%.