Modelling and forecasting reservoir sedimentation of irrigation dams in the Guinea Savannah Ecological Zone of Ghana
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Date
2021
Journal Title
Journal ISSN
Volume Title
Publisher
IWA Publishing
Abstract
Effective management of reservoir sedimentation requires models that can predict sedimentation of the reservoirs. In this
study, linear regression, non-linear exponential regression and artificial neural network models have been developed for the
forecasting of annual storage capacity loss of reservoirs in the Guinea Savannah Ecological Zone (GSEZ) of Ghana. Annual rainfall,
inflows, trap efficiency and reservoir age were input parameters for the models whilst the output parameter was the annual
sediment volume in the reservoirs. Twenty (20) years of reservoirs data with 70% data used for model training and 30% used for
validation. The ANN model, the feed-forward, back-propagation algorithm Multi-Layer Perceptron model structure which best
captured the pattern in the annual sediment volumes retained in the reservoirs ranged from 4-6-1 at Karni to 4-12-1 at Tono. The
linear and nonlinear exponential regression models revealed that annual sediment volume retention increased with all four (4)
input parameters whilst the rate of sedimentation in the reservoirs is a decreasing function of time. All the three (3) models
developed were noted to be efficient and suitable for forecasting annual sedimentation of the studied reservoirs with accuracies
above 76%. Forecasted sedimentation up to year 2038 (2019–2038) using the developed models revealed the total
storage capacities of the reservoirs to be lost ranged from 13.83 to 50.07%, with 50% of the small and medium reservoirs
filled with sediment deposits if no sedimentation control measures are taken to curb the phenomenon.
Description
Water Practice and Technology, 16(4), 1355-1369
Keywords
artificial neural network, forecasting, irrigation dams, linear regression, nonlinear exponential regression, reservoir sedimentation modelling
Citation
Adongo, T. A., Abagale, F. K., & Agyare, W. A. (2021). Modelling and forecasting reservoir sedimentation of irrigation dams in the Guinea Savannah Ecological Zone of Ghana. Water Practice and Technology, 16(4), 1355-1369.