• 研究报告 •

### 基于Gash修正模型模拟侧柏及其混交林的林冠截留过程

1. 1山东农业大学林学院,山东省土壤侵蚀与生态修复重点实验室,泰山森林生态系统定位研究站, 山东泰安 271018；2山东省泰安市水土保持科学研究所, 山东泰安 271018；3山东省莱芜市水土保持办公室, 山东莱芜 271100）
• 出版日期:2019-05-10 发布日期:2019-05-10

### Simulation of canopy rainfall interception of Platycladus orientalis forest and its mixed forest using the modified Gash model.

LI Yi-ran1, MA Rui2, ZHANG Yong-tao1, CHENG Tian-tian3, LI Ze-dong1, NIU Yong1*

1. (1Forestry College of Shandong Agricultural University, Shandong Provincial Key Laboratory of Soil Erosion and Ecological Restoration, Taishan Forest Ecosystem Station of State Forestry Administration, Taian 271018, Shandong, China; 2Institute of Soil and Water Conservation Sciences, Taian 271018, Shandong, China; 3Office of Laiwu Water Conservancy, Laiwu 271100, Shandong, China).
• Online:2019-05-10 Published:2019-05-10

Abstract: The modified Gash model is commonly used to simulate the canopy interception process. We explored its applicability in a Platycladus orientalis pure forest and a mixed forest of P. orientalis andCotinus coggygria located in Badaling Forest Park of Beijing. Data from May to October in 2013 were collected and used to fit the modified Gash model. The sensitivity of the model parameters was analyzed. The results showed that the measured values of throughfall, stem flow and canopy interception in the P. orientalis pure forest were 395.2, 22.3 and 129.5 mmrespectively, and those measured values of the mixed forest were 414.6, 12.2 and 120.1 mm respectively. Based on the modified Gash model, the simulated values of throughfall, stem flow and canopy interception in the pure forest were 415.80, 18.04 and 113.09 mm respectively, with the relative errors being 5.2%, 19.0%, and 12.7% compared with the measured values. The simulated values of the mixed forest were 454.26, 10.27 and 82.40 mm, with the relative errors of 9.6%, 15.6% and 31.4%. The following indices, saturated canopy waterholding capacity (S), average rainfall intensity (R), average saturated canopy evaporation rate (E), canopy density (c), saturated trunk storage capacity (St) and stem flow coefficient (Pt) were used in the sensitivity analysis. The results of sensitivity analyses showed that, in the pure forest, when the parameters varied between -50% to -20%, the simulated canopy interception was the most sensitive to the parameter S, followed by c, R,E, St and Pt. When the parameters varied between -20% to 50%, the parameter S also was the most sensitive factor for the simulated canopy interception, followed by E,R,c, St and Pt. In the mixed forest, when the parameters varied between -50% to +50%, the simulated canopy interception was the most sensitive to the parameter S, followed by E, R, c, St  and Pt. According to results of accuracy analysis, we suggest that the modified Gash Model was more suitable for the P. orientalis pure forest than for the mixed forest of P. orientalis and C. coggygria. The parameter S was a primary factor affecting the accuracy of the model output.