ESTIMATION OF HYDROPOWER POTENTIAL USING HYDROLOGIC MODELLING

Abstract

Estimation of hydropower potential requires primarily the estimation of discharge and head available at a particular site. Discharges data is not always available for all the rivers and stream to calculate the hydropower potential. There are various methods available for estimating the above parameters. An attempt is being made here to calculate the discharge at a site using hydrologic modeling. Hydrologic models are simplified, conceptual representations of a part of the hydrologic cycle. They are primarily used for hydrologic prediction and for understanding hydrologic processes. Use of hydrologic model to determine discharge at a site will minimize the time and expenditure required in preliminary selection of site for a hydropower project. Hydrologic modeling has the capability to serve as a foundation with respect to the watershed perspective approach. It can simulate the rainfall-runoff at any point within a watershed given physical characteristics of the watershed. It is a tool for watershed management, in that a hydrological model can be developed to account for human impact to determine the effect on the magnitude, quantity, and timing of runoff at points of interest. DEM prepared by digitization of topographic map was used to identify site with acceptable head available and to delineate watershed. Applicability of HEC-HMS, software for hydrologic modeling, was checked using average 10 daily discharge data and daily precipitation data for a period of three years. Average 10 daily discharges for a period of five years were then computed from precipitation data of five years using the same model. Hydropower potential for the site selected was than estimated using the head obtained from DEM and 90% dependable discharge computed using the average 10 daily discharges computed from the model.