Climate Change and Saltwater Intrusion along the Eastern Mediterranean: Socioeconomic Vulnerability

 

Lack of access to safe water supply and adequate sanitation services is directly linked to the livelihoods and incomes of the urban poor, with impacts on health and ability to earn, thus exacerbating poverty. This study assesses the socio-economic burden of water quality in a poor urban slum (Tripoli, Lebanon) in terms of increased morbidity and premature mortality using various econometric tools. Results indicate need for targeted interventions at the household and slum levels. Based on an economic benefit analysis, this research can be used by stakeholders to justify infrastructure investment and to pressure decision-makers towards the same purpose.

This paper assesses diarrhea occurrence in two urban slums to identify salient factors influencing case prevalence. Rapid urbanization in settings of poor economic performance and governance has increased the number of people living in urban slums to about 1 billion people worldwide. In this study, water quality analysis showed contamination at the household level due primarily to the location of water storage tanks. Significant difference in diarrhea cases in both study areas correlated with the educational level of household head, financial status, type of water storage tank and cleaning frequency, along with adoption of measures to treat water, or use bottled water.

Coastal aquifers are increasingly threatened by seawater intrusion due to increased urbanization, groundwater exploitation, and global sea-level rise. Pattern diagrams, which constitute the outcome of several hydro-geochemical processes, have traditionally been used to characterize vulnerability to seawater intrusion. However, the formats of such diagrams do not facilitate the geospatial analysis of groundwater quality, thus limiting the ability of spatio-temporal mapping and monitoring. This raises the need to transform the information from current pattern diagrams into a format that can be readily used under a GIS framework to define vulnerable areas prone to seawater intrusion. In this study, a groundwater quality index specific to seawater intrusion (GQISWI) was developed for the purpose of aggregating data into a comprehensible format that allows spatial analysis. The index was evaluated with data from various coastal regions worldwide and then applied at a pilot karstic aquifer along the eastern coast of the Mediterranean Sea.

Concentration data exhibited large spatial variability in salinity levels across districts with Total Dissolved Solids (TDS) levels ranging from a low of 400 to as high as 29,000 ppm. Groundwater chemistry, ionic relationships, hydro-chemical diagrams and groundwater quality indices (GQI) were used to delineate saltwater intrusion (SWI) hotspots. Results of this study can help assess the extent and intensity of SWI and improve existing policy planning and management tools for coastal aquifers. Despite widespread studies of SWI, its investigation in karst aquifers remains limited, particularly in view of the challenges in understanding, characterization, as well as modeling of karst aquifers.

This study aims at developing Groundwater Quality Indices (GQIs) that constitute a reliable tool in defining aquifer vulnerability. For this purpose, water quality sampling campaigns were conducted on 60 groundwater wells during most vulnerable periods of early and late summer to ensure the representativeness of the targeted GQI under worst case conditions. The samples were tested for various water quality indicators, which were then used to develop the GQIs through GIS-based mapping with spatial geostatistical analysis. The results contribute in filling a gap in GQI definition and form a basis for planning effective water quality management towards sustainable exploitation of groundwater resources particularly during summer periods when recharge is limited.