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TitleHYDROGEOLOGY OF SEMARANG DEMAK GROUNDWATER BASIN: AN OVERVIEW AND ITS CHALLENGES IN PRELIMINARY GROUNDWATER FLOW MODELING
Publication TypeConference Paper
Year of Publication2011
AuthorsPutranto T.T., Rüde T.R.
EditorWidarto D.S., Narendra P.H., Kadarusman A.
Conference NameThe 36th HAGI and 40th IAGI Annual Convention and Exhibition
Date Published09/2011
PublisherHAGI IAGI
Conference LocationMakassar
ISBN Number978-979-8126-23-9
Accession NumberJCM 2011
Call Number087
Keywordsaquifer, Semarang Demak groundwater basin, water balance
Abstract

Water becomes a major problem related to the increasing population and converting land used in Semarang Demak basin. Groundwater modeling is one of the main tools used in the hydrogeological sciences for the assessment of the resource potential and prediction of future impact. Understanding of geologic and hydrogeologic of natural system becomes an essential part to develop conceptual model in groundwater modeling. Hydrogeologic cross section based on bore hole data, hydrogeochemistry based on groundwater samples and water balance based on calculation of hydro-meteorologic data are used to define natural system.
Semarang Demak Basin is formed by sedimentary rocks and unconsolidated alluvium. Aquifer systems in Semarang Demak basin can be distinguished into two types which are an unconfined upper aquifer and a confined lower aquifer. The aquifers systems can be distinguished by their compositions into 3 (three) groups, which are alluvium aquifer, damar aquifer and volcani breccia aquifer. Alluvium aquifers comprise 2 groups, which are Garang aquifer and Quaternary marine aquifer. Sodium chloride and sodium bicarbonate are water types of alluvium aquifer, while calcium and sodium bicarbonate is a water type of Damar & Volcanic breccia aquifers. Rainfall, runoff, real evapotranspiration and net urban recharge are the parameters to estimate groundwater recharge which is around 316 mm/a.