DEM数据源及分辨率对HEC-HMS水文模拟的影响

Effects of DEM source and resolution on the HEC-HMS hydrological simulation

  • 摘要: DEM数据源及分辨率会影响流域特征参数的提取,进而影响水文模拟结果.将ASTER 30 m DEM、SRTM 90 m DEM及基于ASTER 30 m DEM的40 m、50 m、60 m、70 m、80 m、90 m重采样DEM作为HEC-geoHMS模型输入,提取流域特征,采用HEC-HMS模型,以西笤溪流域为研究区域,分析2011年6月和2011年8—9月的两场降雨径流过程中,DEM数据源和分辨率对水文模拟输出的影响.研究结果表明,两次径流模拟结果与实测数据拟合都较好,模型确定性系数都大于0.82,但是单峰的洪水模拟效果总体更好,基于SRTM 90 m的模型确定性系数比基于ASTER 30 m DEM、重采样90 m DEM的模型确定性系数都大.基于重采样DEM的模型确定性系数变化较大,而且与分辨率的变化呈非线性关系.在HEC-HMS的模拟中,基于ASTER 30 m DEM和基于SRTM 90 m DEM的模拟输出结果相对误差相差3%~5%,基于SRTM 90 m DEM和基于重采样90 m DEM的模拟输出结果相对误差相差2%~4%,基于重采样DEM的模拟输出结果相对误差相差最大达到了11%.

     

    Abstract: Hydrological simulations are affected by the parameters derived from DEM, which describes the water- shed features. Xitiaoxi River basin was selected to simulate two runoff processes in Jun and Aug to Sep 2011 using the HEC-HMS model with ASTER 30 m DEM、 SRTM 90 m DEM and DEM resample data as input for HEC-geoHMS to derive the basin characteristics. The results showed that, the simulated and observed flood were fitting well and the efficiency coefficients of the model were all larger than 0.82, Uni-modal flood showed a better performance in runoff simulation than multi-modal flood. The efficiency coefficients of model based on SRTM 90 m was larger than based on ASTER 30 m DEM and resampled 90 m DEM. The efficiency coefficients of model based on resampled DEM had nonlinear relationship with DEM resolution. The relative error of HEC-HMS simulations based on ASTER 30 m DEM and SRTM 90 m DEM had a difference of 3%—5%. The relative error of simulations based on the SRTM 90 m DEM and the resampled 90 m DEM had a difference of 2%—4%.The maximum difference between the relative error of HEC-HMS simulations based on the resampled 90 m DEM was 11%.

     

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