Geologi dan Karakteristik Kimia-Fisik serta Relasi Air Tanah dengan Air Sungai Serayu Daerah Notog dan Sekitarnya, Kabupaten Banyumas, Provinsi Jawa Tengah.

Abstract

Puji Rahmawan. 101216024. Geology and Chemical – Physical Characteristics of Groundwater and Its Relation to The Serayu River Notog Region and Surrounding Areas, Banyumas Regency, Central Java Province. This Research contains about the Geological Condition of Notog Region and Its Surroundings within the area ±42 km2. Administratively the research area is located in Patikraja Subdistrict and Rawalo Subdistrict, Banyumas Regency, Central Java Province. This research aims to find out the conditions of Geomorphology, Stratigraphy, Geological Structure, Reconstruction of Geological History, Chemical – Physical Characteristics of Groundwater, and The Relationship between Groundwater and Serayu River. Geomorphology of the research area is divided into five units, namely the Floodplain Unit, Denudational Plains Unit, River Terrace Plains Unit, Homocline Hills Unit, and Anticlinical Ridge Unit. The rock units in the research area are divided into four with old to young sequences, namely the Andesite Breccia Unit, Claystone – Sandstone Unit, Sandstone insertion Siltstone unit, and sedimentary material unit. Geological structures that developed in the research area are Tambaknegara Anticline and Serayu Left Strike Slip Fault. The research area belongs to the Non-Groundwater Basin area and is located between Purwokerto – Purbalingga groundwater basin, Cilacap groundwater basin, and Kroya groundwater basin. Chemical analysis of water samples is analyzed using Piper Diagrams. The results of the chemical analysis of groundwater using three samples had mixed type groundwater fasies and magnesium bicarbonate type. The results of the Serayu River water analysis on two samples had mixed type. Based on the results of groundwater levels and river levels measurements, there is a relationship between groundwater and Serayu River water in the research area is Influent with an alluvium deposits role as aquifers. The relationship is further strengthened by groundwater facies that have similarities with Serayu River water fasies, namely mixed type which indicates that Serayu River water affects the condition of the surrounding groundwater.