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-geo HMS模型输入,提取流域特征,采用HEC-HMS模型,以...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-geo HMS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%。展开更多
This paper deals with an analysis of selected equations used for the determination of a stable longwise slope calculation of torrential rivers of Jajroud in east of Tehran. Irregularity of the gradient, accompanied by...This paper deals with an analysis of selected equations used for the determination of a stable longwise slope calculation of torrential rivers of Jajroud in east of Tehran. Irregularity of the gradient, accompanied by heavy bed-load experiencing abrupt changes of the flow as a result of heavy rainfalls of short duration and high intensity, these are typical features impacting the behavior and characteristics of torrential rivers. The determination of the stable bottom slope, when the river bed is kept unpaved but still provides resistance against harmful effects of rapids, becomes an essential objective of the study. Three methods are used to determine the stable slope： the first is based on tangent tension （shear stress theory）, the second observes a （critical） non-scouring cross-sectional velocity （critical mean channel velocities）, and the third applies the bottom layer velocity （the critical bed velocities）. The mathematical hydraulic model HEC-RAS v. 3.1.3 has been used for the verification of the methods in this research study.展开更多
文摘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-geo HMS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%。
文摘This paper deals with an analysis of selected equations used for the determination of a stable longwise slope calculation of torrential rivers of Jajroud in east of Tehran. Irregularity of the gradient, accompanied by heavy bed-load experiencing abrupt changes of the flow as a result of heavy rainfalls of short duration and high intensity, these are typical features impacting the behavior and characteristics of torrential rivers. The determination of the stable bottom slope, when the river bed is kept unpaved but still provides resistance against harmful effects of rapids, becomes an essential objective of the study. Three methods are used to determine the stable slope： the first is based on tangent tension （shear stress theory）, the second observes a （critical） non-scouring cross-sectional velocity （critical mean channel velocities）, and the third applies the bottom layer velocity （the critical bed velocities）. The mathematical hydraulic model HEC-RAS v. 3.1.3 has been used for the verification of the methods in this research study.
