Availability of the current and future water resources in the Sanaga catchment: the case of Mbakaou and Bamendjing sub-basins

Código

I-EBHE0022

Autores

Valentin Brice Ebodé

Tema

WG 1.08: Deep Explanation & Evaluation for Practices in Hydrological Changes (DEEPHY)

Resumo

To anticipate disasters (drought, floods, etc.) caused by environmental forcings and reduce their impact on its fragile economy, sub-Saharan Africa needs a good knowledge of the availability of current water resources and reliable hydroclimatic forecasts. The objective of this study is to quantify the availability of water resources in two sub-watersheds of the Sanaga (Mbakaou and Bamendjing) and predict its evolution over two future periods (near: 2024-2035 and average: 2036-2050). The SWAT (Soil and Water Assessment Tool) model was used for this. The performances of this model are satisfactory in calibration and validation on the two basins with R2, NSE and KGE greater than 0.68. Bias ± 10% also attest to this good performance. In the two basins investigated, infiltration (GW_RCH), flows, water yield (WYLD) and sediment load (SED) are greater in the middle zone. Conversely, runoff (SURQ) is low in this part of the basins. Evapotranspiration appears to be most important to the East. Two models (CCCma and REMO) predict a decline in water resources in these basins, and two others (HIRHAM5 and RCA4) the opposite. However, based on a statistical study carried out over the historical period (2001-2005), the REMO model seems the most reliable. It predicts a drop in precipitation and runoff in the two basins that do not respectively exceed ?19% and ?31%, regardless of the emission scenario (RCP4.5 or RCP8.5) and the future period considered (2024-2035 or 2036-2050). Climate variability (CV) is the only forcing whose impact will be visible in the dynamics of future water resources, given the insignificant changes expected in the evolution of land use and land cover (LULC) patterns. The results of this study could contribute to improving the management of water resources in the studied basins and the region.