青藏高原中部高寒草甸蒸散发特征及其影响因素

Characteristics and influence factors of the evapotranspiration from alpine meadow in central Qinghai-Tibet Plateau

蒸散发作为水量平衡和能量平衡的重要组成部分,其变化对于农业、生态和水文具有重要的影响。全球变暖导致青藏高原上冻土活动层加厚,改变大气和土壤的水热交换过程,为明确唐古拉多年冻土区的蒸散发在全球变暖大背景下的变化趋势,依托中国科学院冰冻圈国家重点实验室唐古拉站,利用小型称重式蒸渗仪的观测数据分析了2007-2013年蒸散发的变化特征及其影响因素。结果表明:2007-2013年草地生长季实际蒸散发总量呈现递增的趋势;在草地生长季内,草地生长中期的总蒸散量最大,生长初期的总蒸散量最小,但是日蒸散量则是在生长初期最大,生长后期最小;无降水日,草地的蒸散发主要受到净辐射和气温的影响,降雨日的蒸散发则主要受到净辐射和风速的影响。

In this study, the characteristics of evapotranspiration and its influencing factors from 2007 through 2013 were studied by using micro-lysimeter relying on the Tangula Station of State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences. The main conclusion are:(1) there had been an evapotranspiration increasing from 2007 through 2013 during the grass growing season;(2) the total evapotranspiration quantity in the middle growth stage had been the maximum while in the early growth stage had been the minimum, but the average daily evapotranspiration in the early growth stage had been the maximum, while in the later growth stage had been the minimum;(3) the evapotranspiration had been mainly controlled by the net radiation in the absence of precipitation and had been mainly affected by wind speed, and then by radiation.