GEOMETRI DAN PROPERTI AKIFER SERTA PENENTUAN ZONA AIRTANAH PAYAU DI DAERAH DUMAI, RIAU

• Main Author: RUFLI, EDWARD
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69610
• Institution: Institut Teknologi Bandung

The objective of the research is to determine aquifer geometry and its property and boundary of fresh – saline/brackish water. In order to achieve the objective, secondary data analysis (topographic and geologic maps, drilling and pumping test data, water table and chemical data) and field work and laboratory analysis (geoelectric survey and granulometric analysis) have been conducted. All of the data were then analyzed and shown in form of geologic and hydrogeologic cross sections, together with groundwater quality (fresh or saline/brackish). Geologic map, drilling, and geoelectric data analyses show that there are two aquifer systems in the study area: unconfined and confined aquifers. The unconfined aquifer system consists of Minas Formation and it is distributed in south – southwest of the study area. In the area where the aquifer system occurs, geometrically, this aquifer is thickening to the north and south. The confined aquifer system consists of Minas and Telisa Formations in the northern part, and Petani Formation in the southern part. In the area where the aquifer system of Minas Formation occurs, geometrically, this aquifer is thickening to the north and thinning to the west and east. Meanwhile, in the area where the aquifer system of Telisa Formation occurs, geometrically, this aquifer is thickening to the west and east and thinning to the north. In the area where the aquifer system of Petani Formation occurs, geometrically, this aquifer is thickening to the north and south. Result of the analysis of the pumping test data, combined with the result of aquifer system analysis shows that transmissivity of aquifer of Petani Formation is 1.36 x 10-4 – 4.78 x 10-4 m2/sec. Meanwhile, transmissivity of aquifer of Telisa Formation is 4.44 x 10-5 – 6.11 x 10-5 m2/sec. Result of geoelectric data analysis indicates that the unconfined aquifer system of Minas Formation in the study area contains fresh water. Meanwhile, brackish groundwater is found in the confined aquifer of Minas Formation, and distributed in the northern part.