摘要
利用Mann-Kendall趋势检验法对长江源区直门达水文站的资料进行分析,揭示长江源区年径流量在1956-2000年间呈微弱的减少趋势。结合流域气象资料分析,该时段流域内升温明显,最大可能蒸发量呈增加趋势,降水也呈微弱减少趋势。径流变化与降水变化基本一致,降雨-径流关系没有发生明显变化,表明1980-2000年降水量减少是该时段径流量减少的直接原因,温度升高有利于融冰融雪和降水形式的变化,但由于融冰融雪占径流补给的比率相对较小,该时段温度升高导致融冰融雪的增加不足以抵消降水量的减少对径流的影响。径流量季节变化分析,揭示长江源区春季径流呈增加的趋势,这可能与融雪过程提前以及融雪量增加有关。
The discharge data of the source area of the Yangtze River are analyzed through the Mann-Kendall test. The results reveal that the annual discharge has a weak decreasing trend during 1956 - 2000, but has a significant, decreasing trend from 1980 - 2000. The annual air temperature has a significant increasing trend within the basin, while the precipitation has a decreasing trend. The consistent change of discharge and precipitation, and no obvious variation of the relation between precipitation and runoff within the basin, suggest the discharge decease during the 1980 - 2000 period is mainly caused by the reduction of precipitation, and the increase of ice melt, and does did not offset the reduction by reason of the regional warming. The spring discharge has an increasing trend from 1956 - 2000, which may be attribute to the early startup period and strengthening of snow or ice melting.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2007年第1期29-33,共5页
Advances in Water Science
基金
中国气象局气候变化专项资助基金(CCSF2005-2-QH01)
