A review on rill erosion process and its influencing factors

Abstract

Rills are frequently observed on slope farmlands and rill erosion significantly contributes to sediment yields. This paper focuses on reviewing the various factors affecting rill erosion processes and the threshold conditions of rill initiation. Six factors, including rainfall, runoff, soil, topography, vegetation and tillage system, are discussed. Rill initiation and network are explored. Runoff erosivity and soil erodibility are recognized as two direct factors affecting rill erosion and other types of factors may have indirect influences on rill erosion through increasing or decreasing the effects of the direct factors. Certain conditions are necessary for rill initiation and the critical conditions are different with different factors. Future studies should be focused on 1) the dynamic changes of rill networks; 2) the combined effect of multiple factors; and 3) the relationships of threshold values with other related factors.

Sediment load change with erosion processes under simulated rainfall events

“…In many process-based erosion models, the separation of rill and interrill erosion is of significance to improve the precision on sediment load prediction (Rose et al, 1983;Merritt, 1984;Nearing et al, 1989). Previous research made effort on the division of the erosion processes and quantified the flow hydraulic changes in different stages (Sun et al, 2013). For example, Ellison (1947) tried to divide the water erosion process on slope into four sub-processes: rainfall erosion process, runoff erosion process, raindrop transport process and runoff transport process.…”

“…Several factors e.g. rainfall, slope gradient, slope length, and soil type, may have significant impacts on erosion processes (Sun et al, 2013;Fang et al, 2014;Zhang et al, 2018). For example, Berger et al (2010) indicated that rainfall intensity has greater effects than slope gradient on rill development and sediment load.…”

Impacts of rainfall intensity and slope gradient on rill erosion processes at loessial hillslope

“…Many studies have reported that rill erosion is directly controlled by combined actions of runoff and soil (Sun et al, 2013). Other factors may have indirect influences on rill erosion by increasing or decreasing the effects of direct factors (Wirtz et al, 2012).…”

“…An understanding of rill erosion processes is not only significant for the soil erosion prevention on sloping croplands but also of importance to soil erosion prediction models (Nearing et al, 1997;Sun et al, 2013). Therefore, a laboratory study was conducted under controlled experimental conditions.…”

Fingerprinting Sediment Sources After an Extreme Rainstorm Event in a Small Catchment on the Loess Plateau, PR China

“…Therefore, to control soil erosion, it is important to identify the most vulnerable soils and land uses. In regions where water erosion is the dominant, studies on individual slope scale have proven fruitful (Kinnell, 2013;Li et al, 2009;Sun et al, 2013). However, only limited information is available for erosion and sediment characteristics on larger scales, such as catchments and whole river systems.…”