Soil erosion and sediment yield from the degraded Mzinga River Catchment in Uluguru Mountains, Tanzania

Abstract

This paper reports the results of a project started in 2003/04 undertaken to rehabilitate the degraded Mzinga River catchment in Morogoro region, Tanzania by practicing agroforestry ti improve the environment health and the socio - economic well-being of the local community. The land user free choice catchment conservation approach was used. Soil erosion measurements and sediment yield modelling were done to monitor land use practices that contribute to catchment degradation. The results showed very high soil erosion losses on agricultural lands (33 tons/ha) and low soil losses from fallow (4.8 tons/ha) and degraded miombo woodlands (2.4 tons/ha). High soil losses from fields contribute greatly to high sediment loads in the Mzinga river averaging about 17 tons/ha per year. The soil erosion rates on agricultural land and the sediment yield rates from the catchment show the importance of instituting corrective and sustainable conservation measures to ensure clean water supply to downstream uses and sustainable land resources development projects.

KEYWORDS: Catchments rehabilitation /conservation - environmental conservation - sediment yield rates - tree planting