RUNOFF FORECASTING AND DEVELOPMENT OF AN OPERATIONAL PRODUCTION PLANNING MODEL FOR THE BUI HYDROPOWER PLANT IN THE BLACK VOLTA, GHANA

Abstract

The Bui Hydropower reservoir faces a situation of excess inflow in the rainy season and very little inflow in the dry season. This situation has prompted a major focus on the development of an accurate inflow forecasting system as well as optimization strategies for the operation of the Bui Reservoir.

The main contribution of this study is the setting up and calibration of the HBV rainfall-runoff model for reservoir inflow forecasting as well as the development of a framework for the optimal operation of the Bui reservoir.

Two set-ups of HBV-model were made for the Bui catchment. One set-up had gauged rainfall input, and the other set-up had a combined gauged and satellite-derived rainfall input. Both set-ups were calibrated and tested on the available runoff data.

The PINEHBV rainfall-runoff modelling system was used for testing the two set-ups of the HBV-model whilst the PINEHYDRO Hydropower simulation model was used for testing the optimized framework.

The outcome of this study shows that an inflow forecasting system with an R2 of 0.814 and a water balance error of 0.0 - 0.1 mm can be achieved for both set-ups. The optimized framework for the operation of the Bui Reservoir yields much higher energy output (GWh/year), constant power output for most of the time, longer operational time over the year, increased water availability for the dry season and a high average reservoir level.