Impacts of climate change on water resources in arid and semi-arid regions: Chaffar Sector, Eastern Tunisia

Global warming is a worldwide phenomenon causing a temperature increase, which affects water resources. In Tunisia, high temperatures were recorded in the last decades with a warming tendency of about 1.1 degrees C for 2020 and 2.1 degrees C for 2050. The Chaffar region is characterized by an important agricultural activity and a semi-arid climate in which the irregular precipitations reach low values. Its shallow groundwater is overexploited with a disturbed hydraulic balance. A drawdown of its piezometric head has been noticed in the last decade because of high exploitation and rainfall deficit as a consequence of global warming. To highlight the impacts of the climatic changes on water resources in the Chaffar region, a mathematical model was prepared using MODFLOW program. It is of great importance to predict and simulate the effects of global warming on hydraulic head of Chaffar shallow aquifer, which is considered as a forbidden area for creating new wells. Considering a constant consumption, the piezometric maps established for 2020 and 2050 show an important drawdown of the hydraulic heads especially downstream the aquifer. It could be even more alarming by 2050 with a probable seawater intrusion.