Evaluating freshwater lens morphology affected by seawater
intrusion using chemistry-resistivity integrated technique: a case
study of two different land covers in Carey Island, Malaysia
Freshwater lenses are vital to small island
communities but are susceptible to seawater intrusion due
to the physical changes in the shoreline land cover. The
effect of seawater intrusion and irrigation water on a
coastal unconfined aquifer beneath naturally preserved
mangrove and deforested mangrove-barren belt was
investigated in Carey Island. Analysis of the total dissolved
solids (TDS) and earth resistivity (ER) using a geochem�istry-electrical integrated technique gave a TDS–ER rela�tionship capable of predicting freshwater lens morphology
affected by sea-irrigation water. The study result shows
freshwater was fourfold thicker in close proximity of the
mangrove forest than the mangrove barren area; the further
the shoreline from the mangrove thickest section, the less
vulnerable was the seawater intrusion and the more fresh
the irrigation water, and hence the greater the freshwater
availability potential