Analysis of Flow Estimation Methods for Small Hydropower Schemes in Bua River


Any hydropower project requires an ample availability of stream flow data. Unfortunately, most of the hydropower projects especially small hydropower projects are conducted on ungauged river and consequently hydrologists have for a longtime used stream flow estimation methods using the mean annual flows to gauge rivers. Unfortunately flow estimation methods which include the runoff data method, area ratio method and the correlation flow methods employ a lot of assumptions which affect their uncertainty. This study was conducted on Bua River in Malawi to unveil the uncertainties of these flow estimation methods. The study was done on a well gauged catchment in order to highlight the variations between the observed, true stream flows and the estimated stream flows for uncertainty analysis. After regionalizing the homogenous sites, catchments using L-moments, an uncertainty analysis was done which showed that the area method is better followed by the correlating flow method and lastly the runoff data method in terms of bias, accuracy and uncertainty.

Share and Cite:

Kasamba, C. , Ndomba, P. , Kucel, S. and Uamusse, M. (2015) Analysis of Flow Estimation Methods for Small Hydropower Schemes in Bua River. Energy and Power Engineering, 7, 55-62. doi: 10.4236/epe.2015.72005.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Copestake, P. and Young, A.R. (2008) How Much Water Can a River Give? Uncertainty and Flow Duration Curve. Scottish Environmental Protection Agency, Wallingford.
[2] Hosking, J.R.M. (1990) L-Moments: Analysis and Estimation of Distributions Using Linear Combinations of Order Statistics. Journal of the Royal Statistical Society. Series B (Methodological), 52, 105-124.
[3] Hosking, J.R.M. and Wallis, J.R. (1997) Regional Frequency Analysis: An Approach Based on L Moments. Cambridge University Press, New York.
[4] Di Baldassarre, G. and Montanari, A. (2009) Uncertainty in River Discharge Observations: A Quantitative Analysis. Hydrology and Earth System Sciences, 13, 913-921.
[5] Inversin, A.R. (1986) Microhydropower Sourcebook: A Practical Guide to Design and Implementation in Developing Countries. NRECA International Foundation, Washington DC.
[6] Chin, D.A. (2006) Water-Resources Engineering. 2nd Edition, Pearson Prentice Hall, Upper Saddle River.
[7] Foody, G.M. and Atkinson, P.M. (2002) Chapter 1. Uncertainty in Remote Sensing and GIS: Fundamentals. In: Uncertainty in Remote Sensing and GIS, England: John Wiley and Sons, West Sussex, 1-18.

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.