Sediment Yield And Bank Erosion Assessment Of Pra River Basin

Abstract

The Pra River Basin has been engulfed by certain anthropogenic activities particularly illegal

small scale mining (popularly called galamsey) and serious concerns have been raised by

stakeholders within the basin of the level of pollution due to the release of chemicals and

sediments into the water bodies. Fluvial sediment yield data is an essential requirement for

informed decision making on water resources development and management. However,

information on the sediment load of most rivers is very rare due to the lack of financial resources

to regularly undertake sediment yield studies. This study was undertaken to assess the sediment

yield levels, sediment sources and bank erosion within the Pra Basin through field data collection

and spatial modelling to ascertain stakeholder’s perceptions and suggest remedial measures to

the problem.

Suspended sediment concentration measurements were undertaken for 9 months in selected

stream discharge measuring stations within the basin. Daily mean suspended sediment

concentration was determined from which monthly and annual suspended sediment yields were

derived. Sediment source tracking was done using a single tracer 210Pb and the relative

contribution of surface and bank sediments to the fluvial sediment transport was determined

using the simple mixing model. Lead-210 was analysed using the Atomic Absorption

Spectrophotometer (AAS). Bank erosion was assessed using erosion pins. The spatial patterns in

soil erosion and sediment yield were modelled using the revised universal soil loss (RUSLE)

equation integrating it into Geographic Information System (GIS).

Suspended sediment concentration and sediment yield of the Pra Basin were found to be very

high resulting in a high annual specific suspended sediment yield. Bank erosion measurement

revealed very active bank erosion and deposition within the river channel and bank erosion was observed to increase downstream. Sediment source analyses showed that bank material was the

dominant sediments which accounted for over 60% of suspended sediment loads. However,

predicted sediment yields using the RUSLE were very low as compared to observed data.

To promote coordinated development and sustainable management of the resources of the

basin, there is the need to resource agencies in charge of regulating natural resource utilization in

the basin to control land use activities particularly galamsey to ensure the sustainability of vital

ecosystems. The Government also needs to resource financially and improve upon staff strength

of the Hydrological Services Departments and the Sediment Unit of the Water Research Institute

of CSIR to enable them maintain and monitor critical stations for flow and sediment discharge

measurements. Also future research works in sediment yield modelling should consider

deploying a model that is capable of modelling both surface and concentrated sediment

discharges as this will give a better perspective to a comparative assessment between observed

and simulated sediment yield within the Pra Basin.

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APA

Kusimi, J (2021). Sediment Yield And Bank Erosion Assessment Of Pra River Basin. Afribary. Retrieved from https://afribary.com/works/sediment-yield-and-bank-erosion-assessment-of-pra-river-basin

MLA 8th

Kusimi, John "Sediment Yield And Bank Erosion Assessment Of Pra River Basin" Afribary. Afribary, 09 Apr. 2021, https://afribary.com/works/sediment-yield-and-bank-erosion-assessment-of-pra-river-basin. Accessed 25 Jul. 2024.

MLA7

Kusimi, John . "Sediment Yield And Bank Erosion Assessment Of Pra River Basin". Afribary, Afribary, 09 Apr. 2021. Web. 25 Jul. 2024. < https://afribary.com/works/sediment-yield-and-bank-erosion-assessment-of-pra-river-basin >.

Chicago

Kusimi, John . "Sediment Yield And Bank Erosion Assessment Of Pra River Basin" Afribary (2021). Accessed July 25, 2024. https://afribary.com/works/sediment-yield-and-bank-erosion-assessment-of-pra-river-basin