The dynamic process of slope rill erosion analyzed with a digital close range photogrammetry observation system under laboratory conditions

• Published in: Geomorphology (Amsterdam, Netherlands) Netherlands), 2020-02, Vol.350, p.106893, Article 106893
• Main Authors: Jiang, Yanmin, Shi, Haijing, Wen, Zhongming, Guo, Minghang, Zhao, Jun, Cao, Xiaoping, Fan, Yongming, Zheng, Cheng
• Format: Article
• Language: English
• Subjects: 3D laser scanner; Digital close range photogrammetry system; Dynamic monitoring; Rill erosion pattern; Rill network extraction
• ISSN: 0169-555X; 1872-695X
• DOI: 10.1016/j.geomorph.2019.106893

•A digital close range photogrammetry observation system was used.•The dynamic process of slope rill erosion during ongoing rainfall was monitored.•Rill networks and their main parameters were extracted.•The erosion processes of rill morphology were quantitatively described. As the main process of soil erosion in the Loess Plateau of China, rill erosion accounts for a large proportion of the total erosion on the slope. Quantifying the rill shape is crucial for studying the mechanisms and evolution of rill erosion. The objective of this study is to monitor the dynamic process of slope rill erosion using on a digital close range photogrammetry observation system during continuous rainfall. Artificial simulated rainfall experiments were conducted, and images were obtained at different time intervals. We used hydrological analysis and profile analysis tools in geographic information system (GIS) technology to extract rill networks and their main parameters to quantitatively describe the erosion processes of rill morphology. The results showed that (1) compared with the error from the traditional runoff sediment measurement method, the average error of the system for estimating soil loss was -7.06% and 1.05%, respectively, and the highest precision for a single observation was 99.46%; (2) the rill erosion process could be divided into several stages: raindrop splashing - eclipse - drop pit - erosion cave - rill cutting head - rill erosion - rill network; and (3) after rainfall lasted for 80min, the density and the degree of splitting increased continuously, and the maximum rill width and depth both showed fluctuating trends. The area of 7.5m to 9.5m away from the top of the surface was the most active area of rill erosion. The digital close range photogrammetric observation system can accurately obtain evolution information about rill erosion morphology during continuous rainfall, which provides a reference for future studies of soil erosion processes.