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为了验证修正的Gash模型对三峡库区内缙云山典型常绿阔叶林冠层截留模拟的适用性,基于2012年4~7月的气象和林分特征资料以及实测的穿透雨和树干茎流等资料,分析缙云山常绿阔叶林林外降雨、穿透雨和树干茎流特征,并应用修正的Gash模型对林冠截留量进行模拟,对比分析周降雨累计截留量和单次降雨截留量的模拟值和实测值,采用敏感性分析法分析模型参数对截留量的影响程度。结果表明:研究期间共34次降雨,总降雨量为522.1mm,平均降雨强度为1.3mm/h,大部分为低雨强、低雨量级、长历时的降雨;穿透雨量、茎流量和林冠截留量的实测值分别为450.9、9.6和61.6mm,模拟值分别为446.1、7.7和68.2mm,模拟的截留量约高出实测值10.8%,模型能够较好适用于缙云山常绿阔叶林场降雨截留总量的模拟。此外,对模型参数进行敏感性分析得出,以林冠郁闭度c对模拟结果影响最大,其次为平均降雨强度R、林冠持水能力S和林冠平均蒸发速率E,而以树干茎流系数pt和树干持水能力St这2个参数对林冠截留总量影响很小。
In order to verify the applicability of the modified Gash model to the canopy interception simulation of the typical evergreen broad-leaved forest in Jinyun Mountain in the Three Gorges Reservoir Area, based on the meteorological and stand characteristics data from April to July 2012 and the observed penetration and stem flow , The characteristics of rainfall, penetration and stem-stem flow in evergreen broad-leaved forest in Jinyun Mountain were analyzed, and the modified Gash model was used to simulate the interception of canopy. The simulation results of cumulative rainfall per unit rainfall and single rainfall interception The measured value, using sensitivity analysis method to analyze the impact of model parameters on the interception. The results showed that during the study period, there were 34 rainfalls with a total rainfall of 522.1mm and an average rainfall intensity of 1.3mm / h, mostly rainfall with low intensity, low rainfall and long-lasting rainfall. Penetration of rainfall, stem flow and canopy The measured values were 450.9, 9.6 and 61.6 mm respectively, the simulated values were 446.1, 7.7 and 68.2 mm respectively, and the simulated interception was about 10.8% higher than the measured value. The model can be well applied to rainfall in evergreen broad-leaved forest in Jinyun Mountain Interception total simulation. In addition, sensitivity analysis of the model parameters shows that canopy crown c has the greatest effect on the simulation results, followed by the average rainfall intensity R, canopy water holding capacity S and canopy average evaporation rate E, while the stem flow coefficient pt And trunk water capacity St these two parameters on the total canopy interception little effect.