【摘要】 本文以褒河流域为例,引入信息熵的概念量化分析了DEM分辨率对地形特征(坡度、单宽上坡集水面积和地形指数)计算的影响,发现随着DEM分辨率的降低,计算得到的坡度值偏小,单宽上坡集水面积值偏大,从而导致地形指数计算值偏大。在此基础上,再基于不同分辨率的DEM数据得到的地形指数分布,采用TOPMODEL对褒河流域的9场次洪进行模拟,结果表明DEM分辨率降低会使得洪峰流量和径流深增大,确定性系数降低,模型的模拟精度变低,但其对峰现时差的影响不明显。更多还原

【Abstract】 This paper introduced the concept of information entropy for analyzing the influence of DEM resolution on topographic characteristics(slope,upslope area per unit contour length and topographic index) calculation.In this study,it was found that as DEM resolution decreased,the slope values tended to decrease,whereas those of the contributing area tended to increase,which would result in a larger topographic index value.The runoff simulation of 9 flood events was performed by TOPMODEL in the Baohe River Basin.The results show that the decrease of DEM resolution produces the higher flood peak and runoff volume and lower Nash-Sutcliffe efficiency coefficient and there is few effect of DEM resolution on the appearing time of flood peaks.更多还原