Modeling sedimentation rates of Malilangwe reservoir in the south-eastern lowveld of Zimbabwe
Tambara, Edwin Munyaradzi
Chari, Lenin Dzibakwe
MetadataShow full item record
Modelling the sedimentation rates using the Wallingford (2004) equations with the aid of NDVI (remote sensing) to assess land degradation was carried out for Malilangwe reservoir catchment in the south eastern lowveld of Zimbabwe. Siltation life of the reservoir was determined from rate of incoming sediment, trap efﬁciency and reservoir capacity using the Wallingford method. The average rainfall of the study area was about 560 mm while runoff from the catchment ranged from 0.3 mm (minimum) to 199 mm (maximum) with an overall average runoff of 50.03 mm. Results showed that the overall mean annual sediment concentration was approximately 2,400 ppm. The reservoir capacity to inﬂow ratio was estimated at 0.8 with a sedimentation rate of 120.1 tkm-2 year-1. Calculated probability of the dam ﬁlling is 26.8 %. Results also showed that the siltation life of the reservoir was [100 years according to the Wallingford method. The Normalised Difference Vegetation Index (NDVI) showed progressive decline (p\0.05) of the vegetation health from 2000 to 2009. While acknowledging the limitations of techniques used, this study demonstrates in part the effectiveness of sedimentation modelling and remote sensing as a tool for the production of baseline data for assessment and monitoring levels of land degradation in the Malilangwe reservoir catchment.
Additional Citation InformationDalu, T., Tambara, E. M., Clegg, B., Chari, L. D. and Nhiwatiwa, T. (2013). Modeling sedimentation rates of Malilangwe reservoir in the south-eastern lowveld of Zimbabwe. Applied Water Science, 2013 (3), 133–144. DOI: 10.1007/s13201-012-0067-9