A grid-based runoff generation and flow routing model for the Upper Blue Nile basin

Abstract

Abstract A simple water balance model was used to generate monthly water surplus for 0.5° grid cells of the Upper Blue Nile basin. An application of a spatially distributed unit hydrograph method is presented to route generated runoff from the grid cells. The work differs from previous modelling work on the basin in that it accounts the spatial variability of the flow parameters. The study illustrates that velocity is a more significant parameter in determining the response of the basin. The key inference from the simulation with spatially variable parameters is that, if variable velocity zones exist in a basin, then it is important to consider the effect of non-uniform dispersion coefficients as well. The study also demonstrated the successful simulation of the hydrological cycle for a local/national data-poor basin using data sets mainly from global archives.