Fiizumi, NurunSyech, RiadSugianto2013-06-132013-06-132013-06-13Rangga Dwijunanda Putrahttp://repository.unri.ac.id:80/handle/123456789/3680A Research has been done to determine the aquifer and structure of lithology subsurface at Siak Bridge1, 2, and 3 Pekanbaru by using a geoelectric method in Wenner and Schlumberger electrode configurations. The current and voltage were obtained by using geoelectric equipment. These data were processed by excell to acquire the apparent resistivity. The software of Res2Dinv 3.56 and VES were used to analyze the data, which yield the real resistivity of rock and subsurface of lithology. The interpretations of Res2Dinv 3.56 and VES show that the lithology of Siak Bridge 1, 2, and 3 Pekanbaru consists of clay, sand, sand gravel, and hard core such as granite and limestone. The compressed aquifer was identified in Siak Bridge 1 and 3 where as Siak Bridge 2 was identified as free aquifer. The depth of aqiufer obtained by using Res2Dinv and VES differs each other in only 4 meters.otherAquiferlithologySchlumberger methodWenner methodOther