基于HASM的黄土侵蚀地形重建方法研究

Study on Terrain Reconstruction of Loess Erosion Landform Based on HASM

黄土高原是世界上侵蚀最强烈的区域之一,基于当前的地形信息对其地形进行重建可有效估算侵蚀量。该文基于高精度曲面建模(HASM)方法首先建立了黄土高原流域地形重建模型,并以多期人工模拟小流域为实例数据,从微观(坡度)和宏观(等高线)的角度分析了不同侵蚀阶段模拟小流域的地形重建结果,该地形重建结果具有较高精度,且处于侵蚀发育中期的小流域重建结果要优于处于侵蚀发育晚期的小流域重建结果。最后,以高程相对误差为指标定量分析了小流域地形重建的精度,结果显示,两个时期小流域重建结果的相对误差平均值分别为0.55%和0.57%,均方根误差分别为1.99%和2.73%,表明基于HASM方法的黄土流域地形重建方法是可行的。

The Loess Plateau is one of the most serious erosion areas in the word, and terrain reconstruction of the region can be used to estimate the erosion amount. Based on the High Accuracy Surface Model （HASM）, the terrain reconstruction model of the Loess Plateau watershed is established firstly. Taking a multi-stage artificial simulated watershed as an example, the terrain reconstruction results of the simulated watershed at different erosion stages are analyzed from the mierocosmic （slope） and macroscopic （contour） perspectives. The results show that the terrain reconstruction results of the simulated watershed is of high precision,and reconstruction results in the middle stage are better than that in the late stage. Finally, based on the elevation relative error index, the quantitative analysis of the reconstruction accuracy is conducted, and the results show that the average rel tive error of the middle stage and late stage are 0. 55% and 0. 57% respectively,and the root mean square error are 1.99% and 2.73%, respectively,which proves that the loess watershed terrain reconstruction method based on HASM is feasible.