Mapping the groundwater memory across Ireland: A step towards a groundwater drought susceptibility assessment

•National assessment of the memory of groundwater across the Republic of Ireland.•The machine learning model is able to simulate the observed memory.•The study provides a first known high resolution map of the groundwater memory.•Groundwater memory informs on the susceptibility of groundwater to drought.•Lowest drought susceptibility appears in low-elevated areas with thick overburden, and vice versa.