Climate Change Effects on Seawater Intrusion in Coastal Dar es Salaam: Developing Exposure Scenarios for Vulnerability Assessment

This chapter is part of a project that aims to identify climate change vulnerability scenarios for the inhabitants of Dar es Salaam’s coastal areas, with specific reference to the phenomenon of seawater intrusion. The rapid urbanization that has taken place in Dar es Salaam over the past 20 years has resulted in a significant increase in anthropogenic pressure (qualitative and quantitative) on the coastal aquifer, causing an acceleration in groundwater salinization processes, due to both seawater intrusion and the leakage of pollutants. Seawater intrusion could be further amplified in the medium and long term by the expected consequences of climate change. This work presents the conceptual and methodological framework adopted to identify scenarios of population exposure to seawater intrusion, based on specific indicators of the phenomenon and their correlations with climate change representative variables. Based on historical data integrated with a specific hydrogeological survey campaign carried out in 2010, a first application of that framework has been tested on a limited portion of Dar es Salaam’s coastal area. This allowed for a preliminary assessment of seawater intrusion indicators, as well as an evaluation of their efficacy when analyzing the evolution of the phenomenon over the last decade.