PREDICTION OF SURFACE WATER TEMPERATURE OF SOUTH AFRICAN IMPOUNDMENTS

Abstract

Temperature data for 18 South African impoundments were evaluated against Straskraba's global surface water predictive model. All impoundments exhibited quantifiable sinusoidal annual temperature variations which allowed for good predictive capabilities using Straskraba's empirical approach. For each impoundment coefficients for input into the model are presented and factors responsible for variation are discussed. Factors such as summer flooding, altitude, impoundment morphometry and water transparency were identified as being important in influencing the seasonal temperature variation. The global model of Straskraba is useful as a first approximation for surface water prediction, but it is advocated that separate coefficients, based on long-term studies, be developed for individual water bodies.