MODELLING HYDROLOGICAL WATERSHED OF COMOE IN CLIMATE CHANGE CONTEXT

This study aims to assess the evolution of water balance parameters watershed Comoe in a context of climate change. Using the GR2M hydrological model, climate data from the climate model RegCM3 under the A2 emission scenario were simulated to get infiltration, runoff and evaporation and plant transpiration for the periods 1991-2000, 2031-2040 and 2091-2100. Similarly, monthly hydrological and climatic data were used to calibrate the parameters of GR2M hydrological model over the period 1961-1990. The calibration of the hydrological model gave Nash values between 57% to 72%. At validation, Nash criterion varies from 51% to 75%. The results of projection, revealed a decrease in runoff of 18.8% to 34% in 2031-2040 and 40% to 73% in 2091-2100 horizon in different localities. Refills of sheets that are through infiltration could decrease by 7% to 13% in 2031-2040 horizon and 49.3% to 70% in 2091-2100. The decrease in these two consecutive hydrological parameters is, firstly, to falling precipitation of 7.17% and, secondly, an increase in the evaporation and plant transpiration via the temperature increase of 3.6