SWAT模型及SUFI-2算法在秃尾河上游流域径流模拟中的应用

The application of SWAT and SUFI-2 to runoff simulation in Tuweihe (Upper) watershed

通过构建处于干旱和半干旱地区的秃尾河流域(上游)的水文、气象、土地利用土壤等数据库,利用基于分布式的SWAT模型对该流域的水文过程和产流机制进行模拟,并通过改进的SUFI-2算法对模型参数进行不确定分析、率定和验证,探讨SWAT模型在干旱和半干旱流域的适应性。采用1977—1983年的月径流实测数据进行模型率定,用1984—1989年的月径流数据进行模型验证。验证结果表明:该研究流域年径流相关系数(R2)和模型效应系数(Ens)均小于0.6(通常认为当模拟结果期望值大于0.6时,模型能比较准确地描述了研究流域的水文过程);月径流相关系数和模型效应系数超过或者接近0.6的水平;汛期(5—10月)模型径流相关系数和效应系数最高(超过或接近0.8)。研究表明通过改进的SWAT-SUFI模型能较好地模拟研究流域的汛期径流,而对全年径流和枯水期的径流模拟不够理想。

Trough building the hydrology, meteorology, landuse and soil databases of Tuweihe （Upper） watershed in the arid and semiarid climate region, the physically-based distributed hydrological model--SWAT 2005 model was employed in this study to simulate the hydrology process and surface runoff in this watershed. The SUFI - 2 method was used to uncertainly analyze, calibrate and validate the results of SWAT simulation. The runoff data from 1977--1983 in Gaojiabao hydrological station was used to calibrate, and the runoff data from 1984--1989 was employed to verdict the resuhs of simulation. The results of the calibration are： the correlation coefficient （R2） and the model efficiency coefficien! （Ens） of the annual runoff is less than 0.6 （The value of more than 0.6 represents the SWAT model carl greatly sinmlate the study watershed）. As for the monthly runoffs, the correlation coefficient （R2） and the model efficiency eoefl＇icient （Ens） of the annual runoffs are over 0.6 or similar to 0.6. The correlation coefficient （ RE） and the model efficiency coefficient （Ens） of monthly runoff from May to October cover 0.8 or similar to 0.8. Thus, the improved SWAT - SUFI model can be applied to simulate hydrology process and surface runoff of this arid and semi-arid watershed in flood season.