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Response of soil erosion and sediment sorting to the transport mechanism on a steep rocky slope
Han, Zhen1; Wang, Xiaoyan1; Song, Dandan1; Li, Xinxin1; Huang, Ping2; Ma, Maohua2
2019-08-13
摘要A deeper understanding of the sediment characteristics associated with rock fragment content can improve our knowledge of the erosional processes and transport mechanisms of sediments on steep rocky slopes. This research used simulated rainfall experiments lasting for 1 h at a rate of 90 mm h(-1) and employed 5 x 1 x 0.4 m parallel troughs filled with purple soils with different rock fragment volumetric contents (0, 5, 10, 20, 30 and 40%) on a 15 degrees slope gradient. For each simulated event, runoff and sediment were sampled at 1- and 3-min intervals, respectively, to study, in detail, the temporal changes in the size distributions of the eroded sediments. The results show that sediment concentrations, soil erosion rates and soil loss ratios significantly decreased as rock fragment content increased for rock fragment contents from 0 to 40% in purple soils. During the transportation process, clay particles often formed aggregates and were then transported as larger particles. Silt particles were more likely to be transported as primary particles with a low degree of sediment aggregation. Sand-sized particles, which constituted a greater proportion of the original soil than the eroded sediments, were formed from other fine particles and transported as aggregates rather than as primary particles. Suspension-saltation, which mainly transports fine particles of 0.02-0.05 mm and coarse particles larger than 0.5 mm in size, was the most important transport mechanism on steep rocky slopes. The results of this study can help to explain the inherent laws of erosional processes on steep rocky slopes and can provide a foundation for improving physical models of soil erosion. (c) 2019 John Wiley & Sons, Ltd.
关键词rock fragment eroded sediment effective ultimate ratio enrichment ratio particle size distribution transport mechanisms
DOI10.1002/esp.4675
发表期刊EARTH SURFACE PROCESSES AND LANDFORMS
ISSN0197-9337
页码12
通讯作者Wang, Xiaoyan(wxy8388@gmail.com)
收录类别SCI
WOS记录号WOS:000482156400001
语种英语