Application of RUSLE model equation in estimating the sediment yield of the Msimbazi River in Dar es Salaam, Tanzania

ABSTRACT Accurate approaches for predicting the sediment yields in River streams remain a challenge in hydrological studies. The erosion of the land surface and stream banks has resulted in sedimentation in the Msimbazi River along the Jangwani and Kigogo areas, raising the river bed, reducing the river width, and leading to floods downstream of the river. This study aimed to estimate the sediment yield in the Msimbazi River using the RUSLE model. The average rainfall erosivity (R-factor), soil erodibility (K-factor), length and slope steepness (LS -factor), cover management (C-factor), and supporting practices (p-factor) were determined and were used in the RUSLE model to estimate the sediment yield. The results indicated that a total of 3.46 tons/ha/year of sediments yield per year. The upstream area of the Msimbazi River, specifically along the Kisarawe hills, Kinyerezi, and Kazimzumbwi forests, has a lower sediment yield, while the lower reaches in Jangwani and Kigogo areas have higher sediment yields. It is recommended that the Dar es Salaam City Environmental Management Department utilize these results in the management of sediments along the Msimbazi River, including the construction of sediment control facilities and afforesting the river catchments to reduce soil erosion.