| Popis: |
Summary Communities located on small ocean island often face the issue of freshwater scarcity as usually they depend on rainwater. If available, groundwater resources occur in form of freshwater lenses, which are under constant threat from natural and anthropogenic factors, such as rainfall variability, saltwater intrusion, contamination through waste water and intensive farming. The size, extend, and yield of island freshwater lenses depends on various factors, like the size of the island, topography, vegetation, and especially an often complex subsurface geology. An integration of various results can provide a hydrogeological conceptual model of the groundwater system as a base for effective groundwater management ensuring long term use. Here, a study from a small island, 1 km2 in size, in the Andaman Sea offshore Southern Thailand is presented. Altogether four vertical electrical sounding measurements were carried out and combined with geological information and shallow groundwater information from a dug well to draw a conceptual model of the groundwater system. A borehole drilled at the proposed site found and confirmed fresh groundwater in weathered mudstone down to 35 meters but went further and entered the saline water below. After rehabilitation of the well the groundwater can be used by the local villagers. |
