摘要
利用西北及三江源（黄河、金沙江及澜沧江）地区122个气象观测台站1956-2004年近50年的逐日降水量及月总降水量资料，分析了三江源地区降水变化特征。结果表明：近50年来三江源地区的年降水量呈减少趋势，减少幅度为6．73mm／10a；降水日数的趋势变化呈较为明显的减少趋势，递减率为2．7d／10a；平均降水强度总体呈弱的增强趋势，增强速率平均为0．20mm／d／10a，增强幅度比中国西北地区平均水平强；从4～9月最长无降水日数趋于增长反映出西北地区干旱化的趋势。
Based on the daily precipitation data from 122 stations in Northwest China and source regions of three rivers（Yellow river, Jinsha river and Lanchang river） during 1956-2004, the spatial and temporal distributions of trend for precipitation total, precipitation frequency and precipitation intensity are analyzed. The main conclusions are summarized as follows. The annual precipitation in the source regions of the three rivers has decreased by a rate 6.73 mm/10a; and the daily numbers of precipitation has obviously decreased trend, successive decrease rate is 2.7 d/10a; the mean pricipitation intensity appear to weakly strengthen trend, mean speed is 0.20 mm/d/10a. Such change trends are stronger than mean pricipitation in Northwest China. The decreasing of the longest consecutive dry days reflects a drying trend in the source regions of three rivers.
出处
《高原气象》
CSCD
北大核心
2007年第1期47-54,共8页
Plateau Meteorology
基金
中国科学院知识创新工程重要方向项目"中国西北西部气候和水分过程的变化特征及其相互联系的研究"项目(KZCX3-SW-229)资助
关键词
三江源区
降水变化
降水日数
Source regions of the three rivers
Precipitation changes
Daily numbers of precipitation
