Study Condition of Hydrogeology of Gunungpati Area and Surroundings, Semarang, Central Java

Abstract

Important groundwater role progressively because becoming especial water source to fulfill fundamental requirement of intention live a lot of people. Estimated by 70% clean amount of water required of resident and 90% industrial amount of water required come from groundwater. Research area have interesting condition hydrogeology interconnected by the ground water potency, that is ground water emitting a stream of from shares culminate up at hillside growing high, then the ground water accumulate at bevel shares of under mount. Meanwhile ground water at hilly shares decrease its amount, estimated by effect of existence of geology constrictor dissociating area with the high productive potency aquifer and productive potency aquifer lower. Research target that is to know the condition of geology and hydrogeology, potency of groundwater and characteristic aquifer groundwater at research area. Research area located in area Gunungpati and also some of Subdistrict Ungaran and some of Subdistrict Boja, representing area of Sub Groundwater Basin Ungaran and Sub K. Garang. Research method used by descriptive, survey and analyse method. At survey method done with the attempt and checking data in field, then analyse method done with calculation parameter from data secunder also read of data geoelectric and construction drill well. Result got that research area have condition hydrogeology influenced by local structure condition which is normal fault, that is fault which is part of hanging wall make a move relative descend to foot wall.. Appearance of waterproof litology (sandy claystone and claystone) at part of foot wall cause the water at aquifer bed (tuff sandstone) part of hangging wall cannot emit a stream of farther and accumulate at middle part of research area. So that from the geology condition, dissociating area have potency to high groundwater potency at under bevel area and low grounwater potency at surging hill area. Bevel area for Mt. Ungaran of have middle groudwater potency and culminate area have scarce graounwater potency. From knowable geoelectric data that research area there are 2 system aquifer that is unconfined aquifer and confined aquifer.