#TITLE_ALTERNATIVE#

• Main Author: ZAINURI (NIM 22305006), AHMAD
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/7106
• Institution: Institut Teknologi Bandung

Sapeken Island as an interesting area of study was isle, which located in the eastern of Kangean Islands. This study area is approximately 1 square km.<p> <br /> <br /> <br /> <br /> Investigation of resistivity and hydrochemistry carried out to estimate the origin of groundwater and seawater intrusion characteristic in Sapeken aquifer, that geologically, consists of limestone at upper layer and marl at its lower layer. In this study, resistivity measurement was carried out by using resistivity sounding and imaging methods. Resistivity sounding with Schlumberger array was carried out in Brumbung (Paliat Island), consists of four lines, and in Sapeken Island consists of five lines consecutively, the length of electrode separation is 100-150 meters for depth target of 20-30 meters, while resistivity imaging has only been done in Sapeken Island by applying Wenner-Schlumberger array with length of 100 meters and depth target of about 20 meters. Measurement of hydrochemistry was done by collect the samples of well's and/or spring's water from Sapeken Island to islands which is estimated as recharge zones. The simulation of fluid <br /> <br /> <br /> <br /> flows that describe the relationship of freshwater-saltwater in coastal karstic aquifers were created for both of dry and wet seasons.<p> <br /> <br /> <br /> <br /> Results of geoelectric interpretation shows existence of groundwater accumulation zones and also estimable zones as seawater intrusion zones and fault or fracture structures, especially in northern Sapeken aquifer. Water samples analysis shows a variation in degradation trend of hydrochemistry parameters from dry season to wet season. Based on ions analysis, we could detect that hydrochemistry facies of water sample from recharge areas represent of Ca-HCO3, while hydrochemistry facies of spring's Tanjung represents of Ca-Cl and hydrochemistry facies in northern of Sapeken represents of Na-Cl. The simulation result has shown variation in decreasing of salts dissolved concentration from dry to wet season. At wet season, it was still shown a high concentration especially at water samples in southern of Sapeken.