Assessment of sediment yields in barotse sub- catchment of the Zambezi basin using MPSIAC and GIS framework.

Reservoir life usefulness can be estimated from sediment yields. In addition, sediments can affect aquatic habitats; pollute water bodies especially if they originate from agricultural lands and contain residual Phosphates and Nitrates. “Assessment of sediment yields in Barotse sub catchment of the Zambezi basin using MPSIAC and GIS framework” was therefore done in order to estimate present sediment yields. The research used the Modified Pacific South west Inter Agency Committee (MPSIAC) model and Geographic Information Systems (GIS). Field and secondary data were processed using ArcGIS 10.4 in creating nine factor maps namely: Surface geology, Soil erodibility, Climate, Runoff, Topography, Ground cover, Land use, Upland erosion and Channel erosion. These factor maps were then added in map algebra to create the Sediment rating (R) map which was later reclassified into five sediment yield categories. Average Sediment yield was estimated as 2.11 tonnes per hectare per year and is categorized as low and acceptable. In the respective land units, Croplands had the lowest sediment yield whereas built up areas exhibited the highest. Generally tillage practices in cultivated areas promote infiltration as opposed to impervious paving associated with built up places. The low sediment levels in Barotse sub catchment can be attributed to gentle slopes (average 3.2%) and high vegetation cover which simultaneously reduce runoff. Up scaling vegetation cover should always be integrated in future Land conservation programmes so as to reduce soil erosion and ultimately sediment yields.