近20年中国土地利用变化影响区域气候的数值模拟

Numerical Simulation of the Impact of Land Use/Land Cover Change over China on Regional Climates during the Last 20 Years

区域尺度土地利用/土地覆盖变化(LUCC)的气候效应以及土地覆盖数据的不确定性,一直是LUCC研究不可忽视的关键问题。本研究基于最新的遥感资料,采用新的区域气候模式Reg CM4.0,探讨了1990年至2010年中国LUCC对区域气候的影响。结果表明,中国区域LUCC使得局地气温和日较差发生了显著改变,而降水及低层环流场变化不显著;LUCC的影响存在季节性差异,其中,夏秋季响应程度较大且主要体现在边界层内。就LUCC对气候影响的机理各地区有所不同,华北地区LUCC的气候效应主要受蒸散发作用主导,而长江流域则由反照率与蒸散发共同作用。这些结果均说明,较短时间尺度的LUCC气候效应主要体现在其局地范围,且在不同的季节有所差异。

The climate effects of regional-scale land use/land cover change （LUCC）, along with land cover data uncertainties, have typically been the focus of LUCC studies. Based on remotely sensed LUCC data, the Regional Climate Model （RegCM4.0） was used to investigate the climate effects of LUCC over China during the last 20 years. Results show that LUCC in China during the past 20 years has changed the regional temperature and diurnal temperature range significantly, but there has been no noticeable precipitation response or low-level atmospheric general circulation changes. The variation of these climate factors due to LUCC differ among the seasons, with greater responses in summer and autumn, and are mainly reflected in the boundary layer. The mechanisms involved vary significantly between regions. LUCC has exerted stronger evapotranspiration than albedo effects in the modulating North China climate, while the effects from these two factors are of equal importance in the Yangtze River Basin. These results indicate that the impact of shorter time scale LUCC is local and limited.