中文摘要：

地形因子是土壤流失方程中坡度坡长两因子的乘积，用来表示土壤侵蚀中的地形效应，与研究区域的地形地貌特点密切相关：本文以黑龙江省克东县丰收小流域为例，利用1：5万和1：10万地形图建立数字高程模型（DEM），探讨了不同DEM分辨率和地形图比例尺变化所产生的地形因子的尺度效应。认为东北黑土区利用1：5万地形图计算地形因子时，20m格网大小是较理想的DEM分辨率；另外，在利用较小比例尺地形图建立的DEM计算地形因子时，汇水单元的划分不宜过细。

英文摘要：

The product of slope length L and steepness S is called topographic factor LS, implying the topographic effect on soil loss. It has much to do with the topographic character of the study area. Taking Fengshou watershed in Kedong County Heilongjiang Provence as an example, by using of Digital Elevation Model （DEM） created from 1：50000 and 1：100000 topographic map, the scale effect of topographic factor due to DEM grid resolution and topographic map scale were discussed, and the conclusion was drawn. 20m grid size is probably the appropriate DEM resolution of 1：50000 topographic map in black soil area of Northeast China. On the mean while, devision of the hydrological unit should not be down to the last detail when smaller scale topographic map is used to calculate the LS value.