Review: Saltwater intrusion in fractured crystalline bedrock

Abstract

During the past few years, the number of regional and national assessments of groundwater quality in regard to saltwater intrusion in coastal aquifers has increased steadily. However, most of the international literature on saltwater intrusion is focused on coastal plains with aquifers in unconsolidated material. Case studies, modelling approaches and parameter studies dealing with saltwater intrusion in those systems are abundant. While the hydrogeology of fractured rock has been intensively studied with both modelling approaches and parameter studies—mainly in relation to deep-laying fractured crystalline bedrock as potential waste repositories—case studies on saltwater intrusion in shallow fractured rocks are still an exception. This review summarizes the actual knowledge on saltwater intrusion in fractured crystalline rock. In combination with short overviews of the processes of saltwater intrusion, flow in fractured systems and the genesis of these systems, the review highlights the importance of the fracture systems and its specific characteristics. Fracture properties are a direct consequence of the geological history as well as the current situation of the coastal area. A holistic assessment of water quality in coastal areas hosting fractured crystalline bedrock therefore requires the combination of different approaches in order to investigate the impact of saltwater intrusion through the fractured system.

Study of Distribution of Groundwater Salinity in Pacitan Sub-District, Pacitan District Based on GIS

“…In coastal areas, the decrease in groundwater can result in seawater intrusion. The salinity value of groundwater is not only caused by seawater intrusion but is also caused by several factors, namely geomorphology, flow direction, tides, coastal characteristics, and land use [10][11]. Seawater intrusion (salinity) can also cause extensive negative impacts on various aspects of life, such as health problems, decreased soil fertility, damage to buildings, and so on [12].…”

Laboratory and Numerical Study of Saltwater Upconing in Fractured Coastal Aquifers

“…Approximately two billion people rely on freshwater abstracted from fractured aquifers [7], and because of that, their hydrogeological attributes have been investigated extensively over the years [8][9][10][11][12]. Coastal fractured aquifers are generally more vulnerable to saltwater intrusion than other hydrological systems [13].…”