El Mountassir O. auteur aut IRD Bahir M. auteur aut IRD Ouazar D. auteur aut IRD Chehbouni Abdelghani auteur aut IRD Carreira P. M. auteur aut IRD text journalArticle eng text/pdf reformatted digital access The city of Essaouira is located along the north-west coast of Morocco, where groundwater is the main source of drinking, domestic and agricultural water. In recent decades, the salinity of groundwater has increased, which is why geochemical techniques and environmental isotopes have been used to determine the main sources of groundwater recharge and salinization. The hydrochemical study shows that for the years 1995, 2007, 2016 and 2019, the chemical composition of groundwater in the study area consists of HCO3-Ca-Mg, Cl-Ca-Mg, SO4-Ca and Cl-Na chemical facies. The results show that from 1995 to 2019, electrical conductivity increased and that could be explained by a decrease in annual rainfall in relation to climate change and water-rock interaction processes. Geochemical and environmental isotope data show that the main geochemical mechanisms controlling the hydrochemical evolution of groundwater in the Cenomanian-Turonian aquifer are the water-rock interaction and the cation exchange process. The diagram of delta H-2 = 8 * delta O-18 + 10 shows that the isotopic contents are close or above to the Global Meteoric Water Line, which suggests that the aquifer is recharged by precipitation of Atlantic origin. In conclusion, groundwater withdrawal should be well controlled to prevent groundwater salinization and further intrusion of seawater due to the lack of annual groundwater recharge in the Essaouira region. specialized Stable isotopes Essaouira Groundwater Climate change Geochemistry MAROC 062 021 064 3 7 698 [16 ] 2021 2523-3963 https://www.documentation.ird.fr/hor/fdi:010082106 10.1007/s42452-021-04623-3 2523-3963 [F B010082106] https://www.documentation.ird.fr/hor/fdi:010082106 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2021-07/010082106.pdf IRD - Base Horizon / Pleins textes 2021-07-02 2025-02-24 fdi:010082106 fre