A framework for predicting abrasion rupture of crusts in wind erosion

Abstract

Crusts play a crucial role in the reduction or control of wind erosion. In this regard, the resilience and durability of crusts are of prime importance. Crusts have high resilience and durability against wind flow shear stresses; however, they are prone to abrasion induced by saltating particles. Therefore, estimating crust durability in abrasion rupture has practical importance. In this study, a cyanocrust and a biocemented sand crust were subjected to a controlled flux of saltating particles for different sandblasting periods to provide a framework for predicting crust rupture. The velocity and pre-and post-collision energy of the saltating particles were measured using high-speed photography. The changes in the strength of the crusts after different periods of sandblasting were determined using a scratch test. The results suggested that the average strength of the cyanocrust and biocemented sand crust became 0.25 and 0.7 of their corresponding initial values after 30 min of sandblasting. Also, the average stiffness of the cyanocrust and biocemented sand crust decreased to 0.5 and 0.9 of their initial values, respectively. Furthermore, the amount of impact energy absorbed by the crusts increased by the deterioration of the crusts. Compiling the results of the wind tunnel experiment and scratch tests yielded an exponential equation which can be used to estimate crust durability in a given condition of saltation. Based on this equation, the cyanocrust and biocemented sand crust will break down entirely after 23 and 449 min, respectively, at a wind velocity of 6.8 m/s and a saltation flux of 1 g/s/m.

Dust Release during Playa Activation in a Typical Semiarid Steppe

“…In particular, particles carried by high-energy wind impacted the surface, and the crusts were destroyed due to long-term exposure to such impacts, so the surface formed more loose particles in the low wind energy environment. The wind erosion of the surface was further strengthened, and a large number of dust particles was released [22,23]. Finally, the surface was fully activated (Fig.…”

“…Deserts are widespread but contain only <5% clay and silt. Such sediments are transports over limited distances and are not a major source of dust [23,32]. The Gobi Desert was found to contain mainly 63-125 μm particles and to be finer than the average desert particle size (125-250 μm), leading to the generation of more dust [30].…”

Experimental Study on Sand/Bed Collision Over the Gobi Surface

“…The loss of particle energy can be characterized by the CoR, which is related to the material properties, such as cohesion and elastic modulus (Lu & Bao, 2005). Cohesion and elastic modulus characterize the interparticle bonds of the material under an external force (Fattahi et al., 2021). Therefore, we experimentally measured the relevant mechanical parameters (Table 1), including the equivalent diameter ( d ), density ( ρ ), point load strength ( σ ) (Khandelwal & Singh, 2007), effective Young’s modulus ( E ), and cohesion ( P ) (Fattahi et al., 2021; Thornton, 1997).…”

“…In aeolian sand flow, repeated impacts of particles create small microfractures on the surface, which extend from the point of applied local stress, accumulate over time, and weaken the interparticle bonds (Fattahi et al., 2021; Langston & Neuman, 2005; Neuman & Maxwell, 2002). In this process, the incident particles lose their kinetic energy to destroy the interparticle bonds of the material, resulting in a reduction of particle rebound speed.…”

Effects of conservation practices on global wind erosion control: Evidence from experimental data

“…A recent study reported that the saltation process could reduce crust strength and stiffness by up to 0.7 and 0.9, respectively, after 30 min of saltating (Fattahi et al, 2021). In addition to the effects of straw mulching on improvements of soil properties and wind direct impact, it may also significantly reduce the number of saltating particles and their continuous impact.…”