Groundwater is indispensable to humankind, but with the increasing load over this preciousrnresource, it has become necessary to study it in detail with geological as well as hydrogeologicalrnaspectsrnrnto understand the nature of the groundwater resource of a Danakil basin tornmanage it well and use it sustainably, vulnerability assessment of the resource is conducted tornhighlight the areas which are more susceptible to contamination. In the present study, an attemptrnhas been made to account for the groundwater vulnerability using an overlay index method,rnDRASTIC, which is used to prepare a vulnerability map using GIS, of the study area, Danakilrnbasin. The DRASTIC Vulnerability index (DVI) is calculated as the sum of the product of ratingsrnand weights assigned to each of the parameters on a scale of 1 to 10 and 1 to 5 respectively. rnAnd a 2D finite element groundwater flow and solute transport model were developed tornsimulate the spatial and temporal variations of the salinity intrusion in the alluvial aquifer of thernDanakil basin taking into account the transition zone between freshwater and saltwater. Thernavailable historical records of water table levels were used to calibrate the developed model.rnEmphasis was devoted to the response of the transition zone to different pumping scenarios inrnthe study area. The vulnerability index ranges from 50-149 and is classified into three classes itrnreduced approximately 20%, 50% and 30% of the area lies in low, medium, and highrnvulnerability zones. Results from the solute transport model also indicated that the saltwaterrnintrusion problem has evolved during over-abstraction (pumping). Unlike previousrninvestigations, this study presents the most qualitative assessment of the available groundwaterrnin the alluvial aquifer under different pumping scenarios. In conclusion, Danakil basin alluvialrnaquifer is vulnerable to geogenic sources of salt intrusion due to over abstraction. Results can bernan important input for policymakers in the development of sustainable groundwater protectionrnand abstraction strategies for the region.