Rainfall pattern effects on crusting, infiltration and erodibility in some South African soils with various texture and mineralogy

Abstract

Rainfall characteristics affect crust formation, infiltration rate and erosion depending on intrinsic soil properties such as texture and mineralogy. The current study investigated the effects of rainfall pattern on crust strength, steady state infiltration rate (SSIR) and erosion in soils with various texture and minerals. Soil samples from the top 0.2 m layer were exposed to 60 mm•h -1 simulated rainfall. The rainfall was applied either as an 8-min single rainstorm (SR) or 4 x 2-min intermittent rainstorms (IR) separated by a 48 h drying period. Rainfall pattern significantly (p < 0.05) affected crust strength, SSIR and erosion. The IR resulted in higher crust strength and SSIR than SR. The effect of rainfall pattern on SSIR was mostly influenced by the primary minerals, namely, quartz. Therefore, the predicted shift from long duration to short duration rainstorms due to climate change is likely to enhance crust formation and soil loss in semi-arid areas such as the Eastern Cape Province of South Africa.

Impact of successive rainfall events on the dynamic relationship between vegetation canopies, infiltration, and recharge in engineered urban green infrastructure systems

“…The successive rainfall events increased PR in all surface treatment boxes, an observation reported by others (Bullard et al, 2018;Feng et al, 2013;Nciizah & Wakindiki, 2014;Neave & Rayburg, 2007), suggesting that surface crusts developed and progressed due to the raindrop impact-induced processes. The rate of crust development was influenced by the area of the surface that was directly exposed to raindrop impact (e.g., that was not protected by canopy); the crust The lesser increase in penetration resistance was expected in VC boxes because vegetation cover (a) reduces the surface area directly exposed to raindrop impacts, and (b) intercepts and disperses raindrops, dissipating some of the kinetic energy that would otherwise rearrange soil particles and cause a crust.…”

“…The successive rainfall events increased PR in all surface treatment boxes, an observation reported by others (Bullard et al, ; Feng et al, ; Nciizah & Wakindiki, ; Neave & Rayburg, ), suggesting that surface crusts developed and progressed due to the raindrop impact‐induced processes. The rate of crust development was influenced by the area of the surface that was directly exposed to raindrop impact (e.g., that was not protected by canopy); the crust became stronger and continued to develop in the BaS boxes.…”

“…According to Valentin and Bresson (1997) soil crusting can be monitored indirectly through observation of either a decrease in infiltration capacity or an increase in surface strength. Both hand-held and pocket penetrometers have been used to measure surface strength (Bullard, Ockelford, Strong, & Aubault, 2018;Chamizo, Rodríguez-Caballero, Cantón, Asensio, & Domingo, 2015;Felde, Chamizo, Felix-Henningsen, & Drahorad, 2017;Feng, Sharratt, & Vaddella, 2013;Moncada et al, 2014;Nciizah & Wakindiki, 2014;Rathore, Ghildyal, & Sachan, 1983). Following the procedure outlined by Bullard et al (2018), in this study, a Geotester (Yu, 2015).…”

Effects of Cyanobacterial Soil Crusts on Surface Roughness and Splash Erosion

“…Although the vertical surface change may only be of the order of 1–2 mm, these microrelief dynamics can affect hydrological regime by binding particles together and reducing rates of infiltration and splash erosion, but increasing surface runoff and sediment yield (e.g., Agassi et al, ; Bradford & Huang, ; Morin et al, ). Crust formation and resultant resistance of the soil to erosion is substantially controlled by soil texture (e.g., Bedaiwy, ), structure (e.g., Farres, ) and the frequency, intensity, and duration of rainfall events (Fan et al, ; Nciizah & Wakindiki, ). Surface sealing and ponding during physical crust formation typically reduces SSR (e.g., Croft et al, ; Vermang et al, ), although on fine soils under low rainfall the creation of raindrop impact craters may cause an increase in surface roughness (Bullard et al, ).…”

Effects of wetting rate and simulated rain duration on soil crust formation of red loam

“…Soil surface physical crust formation is a common phenomenon in soils exposed to rain (McIntyre 1958). Crust formation results in lower infiltration rate and higher runoff rate, thereby inducing soil erosion (Morin and Winkel 1996;Nciizah and Wakindiki 2014). To better manage the crust-prone soils and to accurately predict the hydrological processes, it is necessary to understand the mechanism of crust formation and its effects on the relevant hydraulic characteristics (Bissonnais and Arrouays 1997; Pathak et al 2013).…”