Assessment of soil erosion hotspots by RUSLE Model using remote sensing and GIS in Morogoro Region, Tanzania

Abstract

Soil erosion is a significant constraint on soil productivity and agricultural endeavors in Sub-Saharan Africa, including Tanzania. The districts of Mvomero, Morogoro urban, and Morogoro rural heavily rely on agriculture, making the preservation of key water bodies like Mindu Dam crucial. The dam and its catchment areas currently face threats from siltation, necessitating effective land and water resource management. Sustainable land management practices are imperative to prevent soil degradation and erosion, and identifying soil erosion hotspots is essential for resource prioritization. This study employs GIS-based analysis using the Revised Universal Soil Erosion (RUSLE) Model to assess potential water-induced soil loss risks in the mentioned districts. The analysis reveals spatial trends and distribution of soil erosion risks due to rainfall. Soil loss magnitudes range from very slight (<2 tons/ha/year) to very severe/catastrophic (>100 ton/ha/year), with mountainous regions being prone to high erosion hotspots. Mvomero district stands out, with 42.8% of its land potentially susceptible to unacceptable soil losses (>5 tons/ha/ year) for tropical and/or shallow highland soils without appropriate support and conservation practices during land use, particularly agriculture. Similarly, both Morogoro urban and rural areas face potential risks of unacceptable soil loss (>5 ton/ha/year), affecting 35% and 38% of their respective land areas. Implementation of support and conservation measures is essential, especially for agricultural activities. The study highlights spatial variability of soil erosion severity, necessitating tailored management strategies in the three districts based on identified erosion hazards.