GLASOD Map

(This study)

Modelling

[10, 3]

Sampling programme (indirect methods and fingerprinting techniques

[10, 3]

v Regional (GLASOD map unit) based sediment sources.

v Subcatchment wise sediment sources identified

v Location specific based sediment sources identified.

v Sheet erosion (top soil removal) dominates in 1DD1 (Kikuletwa) sub-catchment. Not detailed enough to indicate sediment contents and characteristics (organic matter and particle size distribution)

v Sheet erosion dominates in 1DD1 (Kikuletwa) sub-catchment

v Top layer A-horizon or Sheet erosion dominates in 1DD1 (Kikuletwa) sub-catchment. High organic matter content and fine-grained characterize the sediment contents delivered at outlet

v Mass movement depicted, however, it does not tell which type of mass movement (rill, gully formation, riverbank destruction, or landslides)

v Gully erosion is insignificant

v Insignificant gully erosion process in 1DD1 sub-catchment. Based on aerial photos, few and localized growing gullies in some mountain foot slopes

v Indirectly captured as terrain definition or mass movement

v Within channel sediment sources

v Lesser extent within channel sediment sources in 1DD1 sub-catchment. Sediment concentrations delivery at outlet though low are sustained even during low flow or dry season

v Bank erosion in Ruvu River as monitored at 1DC1 gauging station. Sometimes sediment peaks lead the flood peaks.