| Title |
Micromorphological Changes of Rill Development under Simulated Rainfall and Inflow on Steep Slopes |
| Authors |
신승숙(Shin, Seung Sook) ; 심영주(Sim, Young Ju) ; 손상진(Son, Sang Jin) ; 박상덕(Park, Sang Deog) |
| DOI |
https://doi.org/10.12652/Ksce.2023.43.1.0021 |
| Keywords |
세류발달; 미세지형; 세류밀도; 세류예도 Rill development; Micromorphology; Rill density; Rill sharpness |
| Abstract |
Interrill erosion dominates in forest areas, and the erosion rate in surface-disturbed areas is significantly increased by thedevelopment and expansion of rill. In this study, soil erosion experiments using simulated rainfall and inflow were performed tounderstand the development and the micromorphological changes of rill on steep slopes. The characteristic factors of themicromorphology, such as the rill cross section, rill volume, rill density, rill order, and rill sharpness, were analyzed according tosteepness and location (upper or lower) of slope. The head-cut of the simultaneous incised rills by rainfall simulation moved rapidlyupslope, and the randomly developed rills expanded deeply and widely with their connection. The rill cross section evolved todownslope gradually increased. The rill volume occupied about 78 % of the sediment volume, confirming that the contribution ofthe sediment from the rill erosion is greater than that of the interrill erosion. Although the rate of increase in rill order slowed as theslope increased, the total length and density of the rill generally increased. As the slope increased from 15° to 20°, the bed incisionof rills became larger than the sidewall expansion, and the rill sharpness increased by 1.6 times. The runoff coefficient on the lowerslope decreased by 12.3 % than that on the upper slope. It was evaluated that the subsoil exposures and formation changes by therill expansion increased the infiltration rate. Although the sediment accompanying the rills generally increased with slope increase,it was directly influenced by the hydraulic velocity of enhanced rill with the local convergence and expansion in the process of therill evolution. |