Suspended Sediment Content

Abstract

Kilimanjaro ecosystem, which is of local and global significance, is experiencing an extensive degradation and deforestation which include completely deforested patches and enormous soil-erosion gullies. Soil loss as a result of erosion is of concern for different reasons like socio-economic and ecological activities.  The Government of Tanzania, with support from the Global Environment Facility (GEF) through UNDP is implementing a 4-year project aimed at reducing land degradation on the highlands of the Kilimanjaro Region. Activities carried out include rehabilitation of gullies, agro forestry, soil and water conservation measures (terracing and soil-fertility management). This paper also includes measurement of suspended sediment content within the Pangani River Basin at two gauging stations; Kikuletwa River (1DD1) and Ruvu River (1DC2A). These measurements (suspended sediment) data allows for the estimation of sediment yields.Observation of sediment concentration data (secondary data) of years 2005-2006 in August at 1DD1 ranges from 9.8 to 1136.5 mg/L while primary data of year 2014 in August at 1DD1 ranges from 9.333 to 33.667 mg/L. This reveals sediment yield in 2005-2006 are higher than in 2014. The same observed at 1DC2A where secondary data ranges from 0.2 to 13.0 ton/day while primary data ranges from 5.879 to 7.400 ton/day. Although the two sets (collected in August) differ in sample sizes due to limited resources, gives credence to the comparisons, particularly that it is averages that are being compared. Therefore the findings with limited information show that the sediment loading rate for the two rivers, Kikuletwa and Ruvu is declining.

Keywords: Pangani river basin, kikuletwa, ruvu, sustainable land management, suspended sediment content