Prediction of factors affecting activation of soil erosion by mathematical modeling at pedon scale under laboratory conditions

Abstract

Soil degradation due to erosion is a significant worldwide problem at different spatial (from pedon to watershed) and temporal scales. All stages and factors in the erosion process must be detected and evaluated to reduce this environmental issue and protect existing fertile soils and natural ecosystems. Laboratory studies using rainfall simulators allow single factors and interactive effects to be investigated under controlled conditions during extreme rainfall events. In this study, three main factors (rainfall intensity, inclination, and rainfall duration) were assessed to obtain empirical data for modeling water erosion during single rainfall events. Each factor was divided into three levels (− 1, 0, + 1), which were applied in different combinations using a rainfall simulator on beds (6 × 1 m) filled with soil from a study plot located in the arid Sistan region, Iran. The rainfall duration levels tested were 3, 5, and 7 min, the rainfall intensity levels were 30, 60, and 90 mm/h, and the inclination levels were 5, 15, and 25%. The results showed that the highest rainfall intensity tested (90 mm/h) for the longest duration (7 min) caused the highest runoff (62 mm3/s) and soil loss (1580 g/m2/h). Based on the empirical results, a quadratic function was the best mathematical model (R2 = 0.90) for predicting runoff (Q) and soil loss. Single-factor analysis revealed that rainfall intensity was more influential for runoff production than changes in time and inclination, while rainfall duration was the most influential single factor for soil loss. Modeling and three-dimensional depictions of the data revealed that sediment production was high and runoff production lower at the beginning of the experiment, but this trend was reversed over time as the soil became saturated. These results indicate that avoiding the initial stage of erosion is critical, so all soil protection measures should be taken to reduce the impact at this stage. The final stages of erosion appeared too complicated to be modeled, because different factors showed differing effects on erosion.

Scale invariant relationship between rainfall kinetic energy and intensity in Paris region: An evaluation using universal multifractal framework

“…It has been well established that onsite erosion of soil -splash and runoff -depends on drop size distribution (DSD) and fall velocity of the spectrum (Ellison, 1944;Fernández-Raga et al, 2017). Hence, KE and R are primarily used to quantify rainfall erosivity and to estimate erosion rates in universal models towards sustainable land use planning (Angulo-Martínez et al, 2012;Shojaei et al, 2020;Mohamadi and Kavian, 2015). Erosion heavily affects agricultural sector: On on-site level, it impoverishes the top soil off nutrients and organic matter along with their water holding capacity; this in turn increases the use of fertilizers and hence causes pollution at the recipient end of off-site erosion.…”

Environmental drivers of dynamic soil erosion change in a Mediterranean fluvial landscape

“…is a scale-facor modulating the hourly intensity of the intra-seasonal precipitation ϑ, O, σ and φ are calibrated parameters. In fact, the combined effect of rainfall intensity and duration increases sediment yield (by ~24% according to Shojaei et al [43]), compared to the single most important factor (i.e. rainfall duration).…”

Evaluating the impact of flood inundation with the cloud computing platform over vegetation cover of Ganga Basin during COVID-19

“…There have been a few studies that have looked at the effects of factors like inclination, rainfall intensity, and duration on runoff output. A similar study used a mathematical model to accurately anticipate the distinct stages of erosion and runoff to track the influence of these factors on soil loss and runoff production [ 20 ]. Another study used HEC_HMS software to investigate the possibility of prioritizing nine sub-basins in terms of flooding in the Eskandari catchment [ 21 ].…”