考虑径流成分的雅鲁藏布江月径流模拟

通过构建雅鲁藏布江流域分布式水文模型SWAT,并以1989~1998年为率定期,1999~2005年为验证期对3个水文站(奴各沙、羊村、奴下)的月径流进行了模拟。从模型参数组里选取径流成分模拟不同的2组参数,以Nash-Sutcliffe效率系数(NS)、相关系数(R~2)及相对误差(PBIAS)为评价指标,来分析模型的模拟结果好坏。结果表明:率定期内,在径流成分1下奴各沙、羊村站和奴下站的R~2值高达0.9以上,NS系数分别为0.9、0.92和0.72,PBIAS的值为7.1%、18.5%及34.2%,但径流成分与实际情况出入较大。而径流成分2下,模拟得到的评价指标虽然不是很高,但径流成分比较合理。验证期总体结论一致。因此,建议在模型率定验证中要充分考虑径流成分的作用,从而提高模型模拟的精度。

Simulation of Monthly Runoff Considering Flow Components in Yarlung Zangbo River

The semi-distributed hydrological model SWAT was built for the Yarlung Zangbo River Basin. After calibration (1989-1998) and validation (1999-2005), the monthly runoff was simulated at three hydrological stations (Nugesha, Yangcun, Nuxia). We selected two sets of parameters to analyze the performance of SWAT model through Nash-Sutcliffe Efficiency (NS), determination coefficient ( R2 ) and relative error (PBIAS). The results show that for Parameter Set 1, R2 at three stations were as high as 0.9, NS were 0.9, 0.92 and 0.72, PBIAS were 7.1%,18.5% and 34.2% respectively during the calibration. However, the simulations of runoff components are unrealistic. For Parameter Set 2, although the evaluation indexes were not very high, its runoff components are reasonable. This is the same case during the validation. Therefore, it is recommended that the simulation skills of runoff components be considered during model calibration and validation.