Study of seawater intrusion in coastal aquifer using total dissolved solid, conductivity and salinity measurement in Labuhan Kertasari Village, West Sumbawa

Indonesia is an archipelagic country that has a larger ocean area than land, many people live in coastal areas and still experience difficulties in obtaining springs that can be used for their daily needs. This study was conducted to see the extent of seawater intrusion into a coastal aquifer in Labuhan Kertasari Village. The method of measuring Total Dissolved Solids, Conductivity, and Salinity is used in studying seawater intrusion into a coastal aquifer. Coastal aquifer samples were taken from open wells and boreholes belonging to residents which are actively used on a daily basis. Analysis of the relationship between TDS, conductivity and, salinity used simple linearity analysis, and distribution mapping using surfer 8. The highest TDS concentration, conductivity, and salinity were 5770 ppm; 8700 MS/cm; and 4600 ppm on the S8. While the TDS concentration, conductivity, and salinity were the lowest consecutively were 836 ppm; 1258 MS/cm; 700 ppm on S26. In general, the coastal aquifer in residents' wells has experienced various intrusions and has decreased at a distance from the shoreline.