Ecology, Environment and Conservation Paper

MODELING THE STORAGE CAPACITY OF A RESERVOIR SYSTEM IN KELANTAN CATCHMENT EMPLOYING PERFORMANCE INDICES

Issa Saket Oskoui and Rozi Abdullah

Abstract

Storage–Yield–Performance (SYP) relationship is widely applied in water resources engineering particularly for reservoir planning and analysis. The existing SYP relationships in the literature have been developed mostly for over-year storage capacity without considering both reliability and vulnerability performance indices. Hence, Kelantan catchment was selected as a case study to develop a regression equation for total reservoir storage, i.e. (within year plus over year capacities) incorporating reliability and vulnerability performance indices. The reservoir was analyzed using 1000 sequences of synthetic data having the same length as historical data involving both time-based reliabilities and vulnerability performance indices by modified Sequent Peak Algorithm (SPA) for different demands. This method is used to estimate the storage capacity for low flow augmentation and water supply. The results of the modified SPA have been used to develop new predictive equation for the total storage capacity of reservoir systems employing reliability and vulnerability indices in two stages. In the first stage, the exponential relationships are developed for the normalized storage capacity at different reliability and vulnerability indices. In the second stage, the parameters that were obtained in the first stage for the exponential relationships are modeled using the linear regression relationships applying the reliability and vulnerability indices for the study system using the method of least squares. The regression analysis produced statistically satisfactory results for the two stages. Finally, the R2 obtained over the complete range of the storage capacity prediction is high, being 0.9868 for the study system. Hence, the regression equation can be used to estimate the storage capacity in the planning stage of the reservoir.