由卫星OLR及地表反照率资料分析三峡库区气候与生态变化

利用1990～2011年NOAA卫星中国区域OLR资料、以及2000～2011年MODIS全球5 km分辨率地表反照率产品，对库区、西南地区、长江中下游地区的OLR进行了统计分析，统计对比了2003年蓄水前后库区地表反照率的变化特征。研究表明：2003～2011年（蓄水后）与2000～2002年（蓄水前）库区四季地表反照率变化量为：春季+0089%、夏季+008%、秋季-003%、冬季+044%（冬季较大的主要原因为库区西部多为云覆盖，反照率资料受云影响而不准确），地表反照率变化微小，表明了库区土地类型、土壤湿度、植被生长等生态环境蓄水前后变化不大；而从OLR年代际变化来看，2003年以来库区年平均OLR较1990～2002年增加了38 W/m2，呈上升趋势，这一趋势与西南、长江中下游地区OLR年际变化趋势一致，是全球变暖大背景下这些地区的降水日数减少所导致的OLR增加

THE ANALYSIS OF THE CHANGE OF CLIMATE AND ECOLOGICAL ENVIRONMENT OVER THREE GORGES RESERVOIR FROM SATELLITE DERIEVED OLR AND SURFACE ALBEDO PRODUCTS

Based on the NOAA AVHRR OLR product,the interannual variation of OLR in three gorges reservoir and southwest China as well as the middle and lower reaches of Yangtze river was analysed.And by using the MODIS surface albedo product,the change of albedo after and before the reservoir water storage was studied.The following conclusions were obtained.There are similar tendencies of the interannual variation of OLR in the three areas,they indicate the same climatological change characters.The yearly average OLR increased 40、45、49 W/m2 during 2001-2011compared that during 1990-2000 in three gorges reservoir 、southwest China、 the middle and lower reaches of Yangtze river.The increase of yearly OLR is the results of decrease of numbers of pecipitable days in these areas.The changes of surface albedo after and before the reservoir water storage were +0.089%、+0.08%、-003%、+0.44% in spring、summer 、autume 、winter respectively. The little change of albedo explains the minor variations in surface types and vegetation growth which represent the ecological environment of the three gorges dam.〖