Can groundwater vulnerability models assess seawater intrusion?

Abstract

This study examines the uncertainty associated with two commonly used GIS-based groundwater vulnerability models, DRASTIC and EPIK, in assessing seawater intrusion, a growing threat along coastal urban areas due to overexploitation of groundwater resources. For this purpose, concentrations of Total Dissolved Solids (TDS) in groundwater samples at three pilot areas along the Eastern Mediterranean were compared with mapped vulnerability predictions obtained through DRASTIC and EPIK. While field measurements demonstrated high levels of groundwater salinity depending on the density of urbanization, both vulnerability assessment methods exhibited a limited ability in capturing saltwater intrusion dynamics. In the three pilot areas, DRASTIC was only able to predict correctly between 8.3 and 55.6 percent of the salinity-based water quality ranges, while EPIK's predictions ranged between 11.7 and 77.8 percent. This emphasizing that conventional vulnerability models perform poorly when anthropogenic impacts induce lateral flow processes such as seawater intrusion caused primarily by vertical groundwater extraction.

A New Normalized Groundwater Age-Based Index for Quantitative Evaluation of the Vulnerability to Seawater Intrusion in Coastal Aquifers: Implications for Management and Risk Assessments

“…A recent critical review of many data-driven indexing methods [40], but not restricted to GALDIT, concluded their limited ability to predict the salinity patterns associated with SWI dynamics exhibiting a weak correlation with field measurements. Hence, in the sequel of this paper, a newly developed approach is designed to evaluate the specific vulnerability to SWI in a given coastal aquifer system.…”

A geochemical approach in assessing seawater intrusion by integrating geospatial techniques: a case study of Ghiss-Nekor coastal aquifer, Central Rif of Morocco

“…One of the approaches in which interdisciplinary data are combined with geospatial models is vulnerability mapping using "Groundwater Vulnerability Assessment" (GVA) models such as DRASTIC, GALDIT, and EPIK, which are often used to measure the sensitivity of an aquifer to seawater contamination. However, many authors reported the limitations of this approach, namely Momejian et al (2019) and Parizi et al (2019) who proved its limited correlation with SWI indicator measurements (TDS, fsea, GQI), and Momejian et al (2019) also noted that not all vulnerable areas are necessarily polluted at the time of vulnerability assessments. Furthermore, to prevent erroneous interpretations of electrical resistivity profiles, Kura et al (2014) developed a GIS-based solution in which the electrical resistivity data were merged with geochemical data to provide a final map delineating the areas undergoing SWI in the Kapas Island peninsula, Malaysia.…”

Vulnerabilidade À Poluição Da Água Subterrânea No Núcleo Urbano Do Distrito De Monte Alto, Arraial Do Cabo, Rj

“…Segundo Musálem et al (2015), ao longo de décadas, diversos modelos baseados principalmente em técnicas de índice de sobreposição foram desenvolvidos para estudos em contextos geológicos distintos: DRASTIC, SINTACS, AVI, GALDIT e GOD. Estes métodos são baseados na combinação de mapas com fatores hidrogeológicos do aquíferos e outras variáveis, as quais é concedido um valor numérico para cada atributo proporcionando análises que relacionam um conjunto de indicadores físicos in uenciadores na dispersão dos poluentes (Momejian et al, 2019).…”