A semi-distributed hydrological model using rainfall estimates by radar. Application to Mediterranean basins

A semi-distributed rainfall-runoff model is proposed. This model is able to use distributed rainfall fields, particularly from weather radar, and it i s thought to be adapted to hydrological characteristics of Mediterranean ba sins. The catchment is split into hydrological cells of 1x1 km(2), and TOPM ODEL is applied at this cell scale, as runoff generation procedure. Afterwa rds, effective rainfall is routed to the basin outlet, using a cell unit hy drograph which depends on the properties of the travel path. Each cell path way is divided into hillslope path (slow response) and river path (fast res ponse). Finally, all the cell runoffs are added, getting the total runoff. A case study in the Ample basin is presented. A calibration-validation proc ess has been carried out over a set of events, and some results are shown. A comparison against a lumped version of TOPMODEL (using spatially uniform rainfall) is also made. Results show that in general the proposed version c an provide better flow reconstitutions, allowing the integration of radar d ata into distributed hydrological modelling, (C) 2000 Elsevier Science Ltd. All rights reserved.