SWAT模型在天山林区林冠截留过程中的改进应用  

Improvement and application of SWAT Model in canopy interception in Tianshan forest area

作　　者：董力轩 常顺利[1] 张毓涛 DONG Lixuan;CHANG Shunli;ZHANG Yutao(Key Laboratory of Oasis Ecology under the Ministry of Education,Collage of Resources and Environmental Science,Xinjiang University,Urumqi 830046,China;Institute of Forest Ecology,Xinjiang Academy of Forestry,Urumqi 830063,China)

机构地区：[1]新疆大学资源与环境科学学院绿洲生态教育部重点实验室,乌鲁木齐830046 [2]新疆林科院森林生态研究所,乌鲁木齐830063

出　　处：《生态学报》2022年第18期7630-7640,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(U1503187)。

摘　　要：林冠截留是森林生态水文的重要环节,SWAT(Soil and Water Assessment Tool)模型对其模拟过程还较为粗糙,为了在流域水文模拟中更精细的刻画林冠截留过程从而得到更佳的模拟结果,以SWAT模型为基础,使用半理论林冠截留模型(Gash模型)与SWAT模型进行耦合,以天山林区为研究区对SWAT模型林冠截留模块进行优化改进。通过对改进前后的模拟结果进行对比分析,结果表明:1)SWAT模型和SWAT-Gash模型的R~2分别为0.59—0.83和0.65—0.86,NSE值分别为0.58—0.82和0.63—0.85,两种模型PBIAS为7.2%—17.1%,证明SWAT-Gash模型具有更好的适用性;2)相较于出山口径流数据,SWAT模型和SWAT-Gash模型的RMSD值分别为3.49—7.80 m^(3)/s和3.22—4.68 m^(3)/s,SWAT-Gash模型在校准期和验证期的皮尔逊相关系数分别为0.93和0.81,高于SWAT模型的0.91和0.77;3)基于分位数回归(QR)的不确定性分析表明,SWAT模型和SWAT-Gash模型验证期的P因子分别为0.93和0.96,R因子为1.26和1.19,95%不确定性置信区间平均宽度分别为13.50 m^(3)/s和12.86 m^(3)/s;4)SWAT模型与SWAT-Gash模型在验证期的月平均地表径流量分别为6.55 m^(3)/s和8.50 m^(3)/s,表明在该流域内原始SWAT模型会高估林冠截留量。以天山北坡中段林区为例对云杉森林的林冠截留进行精细化模拟,虽然对模型输入数据要求提高,林冠截留数据的收集增加了模型模拟的不确定性,但对本研究区基于物理过程的水文模拟精度提升明显,改进后模型与出山口实测径流数据一致性更强,可以为天山林区小流域水资源管理提供更可靠的依据。Canopy interception is an important part of forest ecological hydrology.The SWAT(Soil and Water Assessment Tool)model is relatively rough in its simulation process.In order to describe the canopy interception process more precisely in the hydrological simulation of the watershed,a semi-theoretical canopy interception model(Gash model)is used to couple with the SWAT model,and the forest canopy interception module of the SWAT model is optimized and improved with the Tianshan forest area as the research area.Through comparative analysis of the simulation results before and after the improvement,the results show that:1)the coefficient of determination(R~2)of the SWAT model and the SWAT-Gash model are 0.59—0.83 and 0.65—0.86,respectively.The Nash-Sutcliffe efficiency(NSE)values are 0.58—0.82 and 0.63—0.85,respectively.The percent bias(PBIAS)of the two models is 7.2%—17.1%.These results reveal the improved performance of the proposed SWAT-Gash approach over the existing approach for catchment-scale streamflow estimation;2)Compared with the outfall runoff data,the root-mean-square difference(RMSD)values of the SWAT model and the SWAT-Gash model are 3.49—7.80 m^(3)/s and 3.22—4.68 m^(3)/s.Pearson correlation coefficients of the SWAT-Gash model during the calibration period and the verification period are 0.93 and 0.81,respectively,which are higher than the SWAT model′s 0.91 and 0.77;3)Uncertainty analysis based on quantile regression(QR)shows that the P factors of SWAT model and SWAT-Gash model verification period are 0.93 and 0.96,R factors are 1.26 and 1.19,and the average width of 95%uncertainty confidence interval is 13.50 m^(3)/s and 12.86 m^(3)/s,respectively;4)The monthly average surface runoff of the SWAT model and the SWAT-Gash model during the verification period are 6.55 m^(3)/s and 8.50 m^(3)/s,respectively,indicating that the original SWAT model would overestimate the canopy interception in this watershed.This paper takes the forest area in the middle section of the northern slope of Tianshan

关 键 词：Gash模型 林冠截留 SWAT模型 径流模拟 云杉森林 

分 类 号：S715.2[农业科学—林学]