Analysis of Msimbazi River Banks Erosion with Regards to Soil Erodibility

Abstract

River bank erosion has become increasingly detrimental to most urban rivers around the world. One of the well-established factors influencing river bank failure especially during a rainy season is the soil erodibility. Msimbazi River is facing severe river banks erosion hazard at different section of the lower basin that have had significant impacts on the population along the Msimbazi River. The study analysed the river banks soil composition from three sections of lower Msimbazi River basin, Kinyerezi, Kigogo and Jangwani, to establish the risk of erosion with regards to soil erodibility. The Results indicated that river banks along the lower Msimbazi River basin are at risk of erosion hazard due insufficient clay content, which is crucial for soil strength against erosion. The ROslan and Mazidah (ROM) Erodibility Index (EIROM) painted that more than 80% of the river banks in the study area are at “high” to “critical” risk of erosion. The banks along Kinyerezi stretch were found to be more prone to erosion while Kigogo and Jangwani ones suffer from overburden deposit of sediment supplied from upstream. River banks characterization presented parameters that can exacerbate river banks erosion thus, aggregate of soil composition with other key parameters is important for effective banks protection.