Assessing the variation of river channel reach inflows on transmission losses

Abstract

Arid and semi-arid regions are characterized by limited water availability throughout the year and highly variable streamflows. River channel transmission losses add another uncertainty to the complex flow regimes. However, the contribution of different factors influencing to transmission losses is poorly understood. In this work we determined whether variations in river channel transmission losses along five reaches of varying lengths could be related to reach inflows in Runde River catchment in Zimbabwe. We directly estimated transmission losses as the difference between reach inflow and outflow discharges. Using simple bivariate regression equations, channel transmission losses were modelled as response variables while reach inflows were the predictor variables. Our results indicate statistically significant positive relationships (p = .000, R2 > 0.05) between inflows and transmission losses for all minor, moderate, and major flow events. This simple approach can be applied in similar settings to understand the variations in transmission losses