近50 年雅鲁藏布江流域潜在蒸散量的变化特征

采用1961-2010 年雅鲁藏布江流域6 个气象站近50 年逐日气温、气压等气象资料,利用Penman-Monteith (P-M) 模型计算了月、季及年的潜在蒸散量(PE),分析了雅江流域PE变化特征。研究表明:流域平均年、干季和湿季PE 呈微弱的增加趋势,增幅均在3.00 mm/10a 以下;PE的年代际变化表明20 世纪60 年代至80 年代,年PE有一个增加的过程,而后减少;雅江流域的PE在1981 年发生突变。

The changes of potential evaportranspiration over Yarlung Zangbo River Basin during 1961-2010

Based on the daily temperature and air pressure datasets recorded by 6 observation stations in the Yarlung Zangbo River Basin during the period 1961-2010, the monthly, seasonal and annual PE (potential evapotranspiration) at this basin was calculated by using Penman-Monteith method, and the changes of PE were analyzed in this paper. The main results were obtained as follows: in terms of annual, wet-seasonal and dry-seasonal variations, there was a weak increasing trend of PE at a rate of less than 3.00 mm/10a. The inter-decadal variation shows that annual PE experienced an increasing process from the 1960s to 1980s, followed by a decreasing trend. The abrupt change of PE was observed in 1981.