【摘要】 以江河源区12个气象台站1971—2008年间的逐月气温、风速和降水资料为基础,对该区气候变化特征进行了分析,结果表明:近40年来,江河源区气候持续变暖,年均气温的增温率为0.37℃/(10 a),1987年和1998年气温由低向高突变;年均风速显著降低,每10 a降幅为0.24 m/s,1981年和1992年风速由高向低突变,年均风速与年均气温间呈负相关关系;1980年代降水偏多,1970和1990年代偏少,21世纪以来降水量有所回升,增幅因区域而异;年陆面蒸发量整体显著增加。结合前人研究,探讨了气候变化对环境的影响:持续升温导致江河源区内冰川退缩、多年冻土退化;1980年代气候相对暖湿,水资源量较丰;气候暖干化、水资源量减少、生态环境恶化是该区在1990年代和21世纪最初几年的显著特征;2004年左右以来,江河源区气候转湿,水资源量增加,生态环境有所好转。更多还原

【Abstract】 Based on the monthly temperature,wind velocity and precipitation data from 12 meteorological stations in the source regions of Yangtze,Yellow and Lantsang Rivers during 1971—2008,the features of climate change in recent 40 years are analyzed,the main results are summarized as follows: the annual mean temperature in the source regions has risen at the rate of 0.37℃/(10 a) and experienced two abrupt changes from low to high in 1987 and 1998 respectively;annual mean wind velocity has decreased notably at the rate of 0.24 m/[s·(10 a)] and abruptly decreased in 1981 and 1992,significant negative correlation is found between annual mean temperature and wind velocity;the decadal mean annual precipitation of the source regions in the 1980s was higher than that in the 1970s and 1990s,precipitation has increased in varying degrees in different subregions since the 21st century;annual evaporation from land surface in the source regions has increased notably since 1971.The impact of climate change on the environment of the source regions has been discussed.Successive climate warming has led to deglaciation and permafrost degradation;water resource in the 1980s was rich because of the relatively warm-wet climate;after the whole 1980s,climate in the source regions changed from warm-wet to warm-dry,which resulted in the reduction of water resource and the deterioration of ecological environment;in recent few years,there is a general tendency that the climate changes from dry to wet,which causes the increase of water resource and yields positive effect on the ecological environment.更多还原