Soil erosion is a continuous process of detachment, transportation, and deposition of soil particles. Obtaining accurate

descriptions of soil surface topography is crucial for quantifying changes to the soil surface during erosion

processes. The objective of this studywas to develop an improved close-range photogrammetric technique to assess

soil erosion under rainfall conditions. Based on high overlapping image acquisition, digital point cloud

matching, digital elevation model (DEM) generation and soil erosion calculation, a digital close-range photogrammetric

observation system was explored and established. The results showed that the established digital

photogrammetric observation systemcould accurately calculate the digital point cloud from the underlying surface

with a 2 min time interval and a 1.5 mm spatial resolution. In addition, based on the DEM generated from

digital point clouds, the amount of soil erosion in different topographic positions within various time periods

was calculated. The digital photogrammetric observation methods explored in our study provide a reliable

way to monitor soil erosion processes, especially under rainfall conditions. This approach can accurately resolve

the evolution of the underlying surface soil erosion, which is of great importance in understanding soil erosion

mechanisms.