Abstract:
Baiquan county, located in the black soil region of Northeast China, was selected as the study area. Based on the high-precision DEM (1:10 000), the difference of topographic factors extracted by low-precision DEM (1:50 000) and its impacts on soil erosion assessment were compared. The main conclusions were as follows: in the southwestern plain and gentle slope area of Baiquan, and the low-lying and easy-lying areas along the Sanhe River (Shuangyang River, Tongken River and Runjin River), the
L factor extracted by 1:50 000 DEM was overestimated by 11% and 25%, respectively. Besides, the
S factor was underestimated by 25% and 31%, respectively. In the northwest and central rolling hills, southeast hills and platform, the
L factor was underestimated by 20% and 7%, and the
S factor was underestimated by 16% and 12%, respectively. Discrepancy existed in soil erosion assessments due to differences in topographic factors. The discrepancy at the plain area is small (10.67%), but at the hilly area was large (up to 23.14%). Therefore, in the soil erosion assessment, in the case where the high-precision DEM was difficult to obtain, the plain area could be replaced by a lower resolution DEM. However, it could not be replaced in the hilly area, necessary modifications must be made of the
LS factor to ensure the accuracy of soil erosion evaluation to a certain extent.