Quantitative analysis of rill erosion and contributing factors in the Oued Aghrouz catchment, Morocco

Rill erosion represents a major form of soil degradation and loss, poses a significant environmental problem and is a serious threat to sustainable development. Various factors, including soil properties, topography, climate, and land use influence its occurrence and progression. Over the past decades, most soil erosion studies have focused on sheet erosion processes. However, research on rill erosion, both at the plot level and across broader spatial scales, remains relatively scarce. This article aimed to examine the impacts and consequences of rill erosion while seeking to identify the factors influencing elementary gully formation in the Oued Aghrouz catchment. Data were collected through measurements of rill dimensions on 12 plots. Descriptive statistics and correlation analyses were used to interpret the findings. The study revealed that the investigated catchment experienced an average soil loss due to rill erosion estimated at 64.9 t/ha, with values ranging from 15.9 t/ha on Vertisols to 151.13 t/ha on Raw Minerals Soil. These losses were recorded during a heavy rainfall event lasting 32 hours, with a maximum intensity of 7 mm/h.