Estimation of water erosion in abandoned quarries sites using the combination of RUSLE model and geostatistical method

Abstract

Worldwide, water erosion is one of the most severe hazards to soil degradation. This study aims to estimate and map water erosion in abandoned quarries in the semi-arid zone of Morocco with the Revised Universal Soil Loss Equation (RUSLE) model coupled to a Geographic Information System (GIS). This study used the RUSLE model to assess water erosion risk in abandoned open-pit quarries. This equation necessitates data collection from many sources in various formats and scales. The GIS program (ArcGIS 10.5) facilitated data processing and management. It was used to spatially process the different layers and evaluate the input data's effect on the soil erosion mapping. The average annual soil loss was calculated by multiplying the five erosion factors: rainfall erosivity, soil erodibility, slope length and steepness, vegetation cover and erosion control practices. The results show that: (i) three quarries (Q3=0.574 t/ha/year, Q4=3.772 t/ha/year and Q5=1.096 t/ha/year) have low soil loss rate, two quarries (Q1=7. 495 t/ha/year and Q2=6.104 t/ha/year) have medium soil loss rate, and (ii) LS and R factors have the most influence on these results. Finally, these results can be an important tool for locating erosion hotspots and help decision-makers make sustainable decisions regarding soil and water conservation.