Application of a revised Gash analytical model to simulate subalpine Quercus aquifolioides forest canopy interception in the upper reaches of Minjiang River
应用修正的Gash解析模型对岷江上游亚高山川滇 高山栎林林冠截留的模拟

Based on rainfall data, weather information and forest structure from June to September in 2007, we applied the revised Gash analytical model to simulate subalpine Quercus aquifolioides forest canopy interception in the upper reaches of Minjiang River. The results showed that the canopy storage capacity was 0.23 mm, the stem storage capacity was 0.041 mm, the stemflow partitioning coefficient was 0.013, and the amount of rainfall needed to saturate the canopy was 0.3 mm. The canopy interception was 80.2 mm during the study period, which was 16.5% of total rainfall, whereas the total interception by applying model was 81.8 mm which was higher over l.6 mm of measured value. There was a good consistency between the simulated and measured value in the weekly cumulative amount of canopy interception and stemflow. The sensitivity analysis indicated that the revised Gash analytical model was the most vulnerable to be influenced by the canopy water storage capacity, followed by canopy coverage, stem water storage capacity, and stemflow coefficient as well during the study period in the subalpine Q. aquifolioides canopy interception in the upper reaches of Minjiang River. Our result suggested that the revised Gash analytical model with a physical basis was an effective tool in estimating and budget the canopy interception in a subalpine Q. aquifolioides forest.