摘要
选择Gash(1995)改进后的模型对祁连山东部青海云杉林冠层截留进行模拟。首先在2009年的5月底至9月期间对降水事件、降水截留和林冠结构进行观测,其次对林冠附加截留量进行计算,在不同的时间步长上利用Gash模型模拟截留量,最后对模型参数进行敏感性分析。结果表明:Gash模型对整个观测期间林冠截留模拟值比实测林冠总截留量偏低8.70%,15 d尺度和次降雨事件尺度上模拟值比观测值分别偏低18.92%和14.23%;附加截留占总截留的74.94%,吸附截留占总截留的25.06%;饱和林冠的平均蒸发强度和降雨强度的比值是模型的敏感性参数,精确获得平均蒸发强度是保证模型精度的前提条件,并且独立降水事件的界定是提高Gash模型的关键点。
The improved Gash model （1995） was used to simulate the rainfall interception by Qinghai spruce forest in the eastern part of Qilian Mountains. Firstly, precipitation, rainfall inter- ception and canopy coverage were measured from the end of May to September in 2009. Second- ly, canopy evaporation was calculated by Penman-Monteith method. Thirdly, interception was simulated by Gash model at three time scales （i.e., the observed period, 15 days, and rainfall events during the observed period）. Finally, sensitive analysis of parameters in Gash model was made. The results showed that the estimated interception value by Gash model at the whole ob- served period scale was 8.70% lower than the observed value. The estimated values were 18.92% and 14.23% lower than the observed values respectively, at 15 days scale and rainfall event scale. The interception amount by canopy evaporation accounted for 74.94% of total interception, and the adsorption interception amount by canopy accounted for 25.06% of total interception. The ratio of average evaporation capacity to rainfall intensity is an important parameter of Gash model. The paper suggested that canopy evaporation during a precipitation event should play a key role in improving the accuracy of Gash model, and independent rainfall events should be defined for bet- ter estimation of rainfall interception by Gash model.
出处
《生态学杂志》
CAS
CSCD
北大核心
2015年第1期288-294,共7页
Chinese Journal of Ecology
基金
国家自然科学基金重点项目(91025015)资助
关键词
降雨事件
敏感性分析
祁连山东部
precipitation event
sensitive analysis
eastern part of Qilian Mountains.
