PENYELIDIKAN DAN PEMETAAN AKUIFER AIR BAWAH TANAH DALAM UNTUK SUPLAY KEBUTUHAN AIR BERSIH DI KECAMATAN RETEH KABUPATEN INDRAGIRI HILIR PROVINSI RIAU

Abstract

This research conducted to deep groundwater aquifer mapping for fresh water supply in sub district Reteh Indragiri Hilir Regency of Riau Province. There are nine of Villages have been measured using Schlumberger configuration geoelectric method. The result of the research there are four formation layers in that region. The result also correlated with regional geology formation map which formation rock is consisting of the alluvium of upper Minas and Palembang formations. The result of geoelectric measurement from top to bottom layers, the first layer has resistivity average < 100 Ωm with 7.5m – 15m average thickness, interpreted as peat moss and soil contain water brackish. The second layer has resistivity average 90 to 150 Ωm with 50m to 130m average of thickness, interpreted as unconsolidated sandstones and clay, this layer consist of free aquifer saturated groundwater which is intruded water surface. The third layer has resistivity 250Ωm with 50m to 120 m average of thickness, interpreted as compact and consolidated sandstones which are contain fresh groundwater supplay. Finally the fourth layer has resistivity >> 4000Ωm interpreted as hard rock (bedrock), compact and impermeable. From nine villages conducted geoelectric measurement possibility there are any aquifer and fresh groundwater supply, but do not have artesis source, this match to local geology which is formation are stream terrace and alluvial