摘要
The Abdus Salam International Centre for Theoretical Physics（ICTP） Regional Climate Model version 3（RegCM3） is used to investigate the climate effects of land use change related to agriculture over China.The model is driven by the European Center for Medium-range Weather Forecast 40-yr Re-Analysis（ERA40） data.Two sets of experiments for 15 yr（1987-2001） are conducted,one with the potential vegetation cover and the other the agricultural land use（AG）.The results show that the AG effects on temperature are weak over northern China while in southern China a significant cooling is found in both winter（DecemberJanuary-February） and summer（June-July-August）.The mean cooling in the sub-regions of South China（SC） in winter and the sub-regions of Southeast（SE） China in summer are found to be the greatest,up to 0.5°and 0.8 ℃ ,respectively.In general,the change of AG leads to a decrease of annual mean temperature by 0.5-1 ℃ in southern China.Slight change of precipitation in western China and a decrease of precipitation in eastern China are simulated in winter,with the maximum reduction reaching-7.5% over SE.A general decrease of precipitation over northern China and an increase over southern China are simulated in summer,in particular over SE where the increase of precipitation can be up to 7.3%.The AG effects on temperature and precipitation show strong interannual variability.Comparison of the climate effects between AG and the present-day land use（LU） is also performed.In southern China,the ratio of temperature（precipitation） changes caused by AG and LU is greater than（closer to） the ratio of the number of grid cells with changed vegetation cover due to AG and LU variations.
The Abdus Salam International Centre for Theoretical Physics（ICTP） Regional Climate Model version 3（RegCM3） is used to investigate the climate effects of land use change related to agriculture over China.The model is driven by the European Center for Medium-range Weather Forecast 40-yr Re-Analysis（ERA40） data.Two sets of experiments for 15 yr（1987-2001） are conducted,one with the potential vegetation cover and the other the agricultural land use（AG）.The results show that the AG effects on temperature are weak over northern China while in southern China a significant cooling is found in both winter（DecemberJanuary-February） and summer（June-July-August）.The mean cooling in the sub-regions of South China（SC） in winter and the sub-regions of Southeast（SE） China in summer are found to be the greatest,up to 0.5°and 0.8 ℃ ,respectively.In general,the change of AG leads to a decrease of annual mean temperature by 0.5-1 ℃ in southern China.Slight change of precipitation in western China and a decrease of precipitation in eastern China are simulated in winter,with the maximum reduction reaching-7.5% over SE.A general decrease of precipitation over northern China and an increase over southern China are simulated in summer,in particular over SE where the increase of precipitation can be up to 7.3%.The AG effects on temperature and precipitation show strong interannual variability.Comparison of the climate effects between AG and the present-day land use（LU） is also performed.In southern China,the ratio of temperature（precipitation） changes caused by AG and LU is greater than（closer to） the ratio of the number of grid cells with changed vegetation cover due to AG and LU variations.
基金
Supported by the China Meteorological Administration R&D Special Fund for Public Welfare (meteorology) under Grant No.GYHY200806010
the National Basic Research Program of China under Grant Nos. 2009CB421407 and 2010CB428400
