DEM分辨率对产流产沙模拟影响研究

地形状况决定流域基本特征，因此在进行流域水文过程模拟时，DEM分辨率会影响流域特征参数的提取，进而影响模拟结果。在研究流域模拟过程中DEM分辨率对流域参数提取及产流产沙模拟的影响，选择黄河下游支流洛河卢氏水文站以上流域为研究区，采用Resizecell技术对1:25万DEM图进行单元栅格处理，分别生成100m×100m、200m×200m、300m×300m和400m×400m四种不同分辨率的DEM图；分别模拟四种情况下1997～1999年流域的产流量与产沙量，进而分析DEM分辨率对模拟结果的影响。研究表明:DEM分辨率对亚流域的面积或个数的提取影响不大，但对坡度值的提取影响较大。其中，400m×400m的DEM与100m×100m的DEM相比，1997～1999年产流模拟结果分别相差9.12%、9.71%、19.52%，产沙量模拟结果分别相差42.25%、43.56%、49.70%。因此，在进行流域产流、产沙模拟时，应进行坡度订正。

Effects of DEM Resolutions on Simulated Runoff and Sediment Yields

Hydrological model simulations are affected by parameters derived from DEMs with different resolutions, which describes the watershed features. The upper range of Luohe River was selected to simulate runoff and sediment yields using the GIS-based SWAT model with four DEM resolutions. The results showed no differences among derived watershed parameters under varying resolutions of DEM, but greater differences for derived slopes. It is important to modify slopes for simulations of runoff and sediment yields. Compared with the lowest resolution of DEM, the changes for the runoff of the highest resolution of DEM was 9.12%～19.52% during 1997～1999, and the changes for the simulated sediment yields of the highest resolution of DEM was 42.25%～49.7% during 1997～1999. In addition, seasonal rainfall distribution and intensity had effects on the simulations.