Distributed hydrological modelling of the Senegal River Basin - model construction and validation

A modified version of the physically-based distributed MIKE SHE model code was applied to the 375,000 km(2) Senegal River Basin. On the basis of conve ntional data from meteorological stations and readily accessible databases on topography, soil types, vegetation type, etc. three models with differen t levels of calibration were constructed and rigorous validation tests cond ucted. Calibration against one station and internal validation against eigh t additional stations revealed significant shortcomings for some of the ups tream tributaries, particularly in the semi-arid zone of the river basin. F urther calibration against additional discharge stations improved the perfo rmance levels of the validation for the different subcatchments. Although t here may be good reasons to believe that the model operating on a model gri d of 4 x 4 km(2) to a large extent reflects held conditions at a scale smal ler than subcatchment scale, this could not be validated due to lack of spa tial data. (C) 2001 Elsevier Science B.V. All rights reserved.