The effects of rainfall intensity and rock fragment cover on soil hydrological responses in Central Chile

Abstract

In Chile, 60% of the usable land is affected by erosion and the effects of rock fragment cover, however protecting the soil against these degradation processes have been sparsely studied. Understanding the effects of rainfall intensity and rock fragment cover on soil hydrological processes is a major challenge for the formulation and implementation of proper soil conservation plans. The effects of rock fragment cover on soil erosion rate, surface runoff, sediment concentration and infiltration rate were studied on a Cambisol in Central Chile using the CAZALAC rainfall simulator. Nine rainfall simulations consisting of different combinations of rainfall intensities (70 mm h -1 , 90 mm h -1 , and 120 mm h -1 ) and rock fragment cover (0%, 40%, and 70%) were carried out. Rock fragment cover contributed to delay the time to start surface runoff and the amount surface runoff was in most of the cases directly proportional to rainfall intensity and inversely proportional to rock fragment cover percentage. Rock fragment cover reduced surface runoff in up to 72.06% in the case of the highest rainfall intensity. Final infiltration rate increased directly proportional to the percentage of rock fragment cover for each of the studied rainfall intensities. Erosion rate tended to be reduced by rock fragments (82.2% of reduction in the case of the highest rainfall intensity and rock fragment cover), but this positive effects were not always proportional to rock fragment cover percentage. In general, lower sediment concentrations were found in covered soils (more than a tenfold reduction in the case of 120 mm h -1 rainfall intensity).

Characterization of the evolution of runoff‐sediment relationship in Min River based on coupling coordination theory

“…Climate change and human activities in the basin can alter the source, formation, quantity, and transport of river runoff and sediment (X. C. Ye et al, 2020). Increasing temperatures accelerate the hydrological cycle, alter precipitation and evapotranspiration patterns, and increase the frequency of extreme weather conditions (Jiao et al, 2022), Heavy precipitation deepens soil erosion and runoff production and confluence effects in the basin, increasing the amount of sediment in the river (Azari et al, 2016; von Bennewitz & Aladro, 2017). With global industrialization, the scope of human transformation of nature is expanding, and its impact is becoming more far‐reaching.…”

Development of a Rainfall and Runoff Simulator for Performing Hydrological and Geotechnical Tests

“…Several studies have presented the development, calibration, and use of RSs for a wide range of purposes, such as agricultural research [17][18][19][20][21][22]; biomass studies [23,24]; infil-Sustainability 2021, 13, 3060. https://doi.org/10.3390/su13063060 https://www.mdpi.com/journal/sustainability Sustainability 2021, 13, 3060 2 of 22 tration analysis [14,15,25,26]; urban hydrology simulation, including permeable pavement performance [27], evaluation of processes of accumulation and transport of pollutants on pavements and roof surfaces [28][29][30][31][32]; and rainwater quality research. RSs are frequently used in geotechnical evaluations of soil loss and erosion [1,16,22,[33][34][35][36][37][38], slope stability [13,39,40] and infiltration, and percolation in unsaturated soils [12,14,15,41,42].…”

Effects of Simulated Gravel on Hydraulic Characteristics of Overland Flow Under Varying Flow Discharges, Slope Gradients and Gravel Coverage Degrees

“…In addition, the soil nutrient content and composition are impacted by erosion transport, which further affects the global biogenic factor cycle 6–8 . Thus, soil erosion is among the major ecological and environmental problems worldwide 9,10 . Soil erosion is affected by various factors, including the rainfall intensity, topography, soil properties, land cover and other factors.…”

“…Von-Bennewitz et al . 9 indicated that gravel cover contributed to delaying the start time of surface runoff, and showed that the amount of surface runoff was directly proportional to the rainfall intensity and inversely proportional to the gravel coverage degree. However, the results may differ with a high gravel coverage degree.…”