The impact of land use and land cover change on regional climate over East Asia during 1980-2010 using a coupled model

摘要

The land use and land cover change (LULCC) presents the large-area features since the 1980s in East Asia, particularly over China, where the largely complicated LULCC has happened for the simultaneous interconversion of croplands, forests, grasslands, and urban lands. In this study, the regional coupled model AVIM-RIEMS2.0 with dynamic vegetation process is employed to examine the impacts of LULCC on regional climate over East Asia. The results show that regional climate and terrestrial surface processes exhibit significantly seasonal and interdecadal signals in East Asia. With the influences of LULCC, forest increased 33.3% and 20.3% from the 1980s to 1990s and from the 1990s to 2000s, respectively. Meanwhile, cropland decreased 17.8% in the 1990s (compared to the 1980s) and 24.8% in the 2000s (compared to the 1990s), respectively. These transitions of land surface processes are roughly coincident with the interdecadal variations in temperature and precipitation, which trigger generally opposite changes in the 1980s as compared to the 1990s, especially over eastern China. The seasonal variability of climatic components is more evident in winter than summer, except for the precipitation. The climate change is also somewhat remarkable under the non-LULCC conditions, combined with the changes in wind fields at the 850 hPa from the simulations during three decades; they together suggest that climate change is also modulated by other controlling factors, such as East Asian monsoon circulations in addition to LULCC conversions. These results highlight the importance of LULCC in regional modeling studies, which would have practical significance in climate mitigation and adaptation over East Asia.