H163-0002
Assessing the Effects of Climate Change on Groundwater Resources using an Ensemble of Climate Simulation in the Southern Mali: Case of Koda Catchment
Assessing the Effects of Climate Change on Groundwater Resources using an Ensemble of Climate Simulation in the Southern Mali: Case of Koda Catchment
Tuesday, 15 December 2020
Poster
Abstract:
Groundwater is significantly requested in all the activities of the inhabitants of the Koda Catchment, the studied area. These resources are affecting by many drivers especially Climate Change. The knowledge of climate change projected effects on groundwater recharge is then the key word on water resources management system, in particular for the decision makers of the Koda Catchment.
This study evaluates the effects of Climate Change on groundwater resources in a semi‐arid catchment in Mali, West Africa. The Hydrogeological modeling has been done using conceptual Gardenia model. The past period of 30 years (1987-2016) climate data has been used as the baseline period and that for the projected was from 2021 to 2050. The projected Rainfall and Temperatures, derived from the outputs of Regional Climate Models (RCM) Rossby Centre Atmosphere model version 4 (RCA 4) downscaled from two Global Climate Models GSMs (IHEC-EC-EARTH and MPI-M-MPI-ESM-LR) under two Representative Concentration Patways RCP 4.5 and RCP 8.5 Scenarios, were statistically downscaled and corrected using Multiscale Quantile Mapping bias correction method. The Potential Evapotranspiration was estimated using Blaney and Criddle 1960 method and used as the inputs of the Gardenia model while the groundwater levels in three piezometers were used to calibrate and validate the Gardenia model. The results show that, during the period of rainy season, from July to October, the groundwater level decreases in the piezometers within Koda Catchment for the period 2021- 2050 compared to the baseline. The RCP 4.5 projects a decrease of groundwater recharge in in both RCM/GCM pairs (RCA 4/ IHEC-EC-EARTH and RCA 4/ MPI-M-MPI-ESM-LR). The opposite is observed in the projection of RCP 8.5 scenario, i.e., the recharge decreases in RCA 4/ IHEC-EC-EARTH model while it is increasing in RCA 4/ MPI-M-MPI-ESM-LR model. It is obvious that this decrease of the recharge is more significant in RCP8.5 scenario than in RCP 4.5 scenario within the Koda catchment. The results also show that the maximum recharge in the future is below the present dry conditions, which might lead to scarce groundwater resource in future.
Keywords: Climate Change; Gardenia model; Recharge; Impacts, Southern Mali, Koda catchment.
This study evaluates the effects of Climate Change on groundwater resources in a semi‐arid catchment in Mali, West Africa. The Hydrogeological modeling has been done using conceptual Gardenia model. The past period of 30 years (1987-2016) climate data has been used as the baseline period and that for the projected was from 2021 to 2050. The projected Rainfall and Temperatures, derived from the outputs of Regional Climate Models (RCM) Rossby Centre Atmosphere model version 4 (RCA 4) downscaled from two Global Climate Models GSMs (IHEC-EC-EARTH and MPI-M-MPI-ESM-LR) under two Representative Concentration Patways RCP 4.5 and RCP 8.5 Scenarios, were statistically downscaled and corrected using Multiscale Quantile Mapping bias correction method. The Potential Evapotranspiration was estimated using Blaney and Criddle 1960 method and used as the inputs of the Gardenia model while the groundwater levels in three piezometers were used to calibrate and validate the Gardenia model. The results show that, during the period of rainy season, from July to October, the groundwater level decreases in the piezometers within Koda Catchment for the period 2021- 2050 compared to the baseline. The RCP 4.5 projects a decrease of groundwater recharge in in both RCM/GCM pairs (RCA 4/ IHEC-EC-EARTH and RCA 4/ MPI-M-MPI-ESM-LR). The opposite is observed in the projection of RCP 8.5 scenario, i.e., the recharge decreases in RCA 4/ IHEC-EC-EARTH model while it is increasing in RCA 4/ MPI-M-MPI-ESM-LR model. It is obvious that this decrease of the recharge is more significant in RCP8.5 scenario than in RCP 4.5 scenario within the Koda catchment. The results also show that the maximum recharge in the future is below the present dry conditions, which might lead to scarce groundwater resource in future.
Keywords: Climate Change; Gardenia model; Recharge; Impacts, Southern Mali, Koda catchment.