Characteristics of Groundwater Aquifers in East Lampung Regency, Indonesia

Groundwater has a crucial role because its use is needed in daily life. The existence of groundwater is found at different depths, because it depends on local geological conditions. Although its availability is abundant below the surface, the public needs to obtain information about the existence of groundwater. Analysis of the data from the IP2Win software to determine the type of rock layer that is arranged in the research area refers to the calculation of type resistance. Furthermore, this research inputs the results of IP2Win data processing into the RockWorks software to find out a 3D picture of the distribution of resistivity values, lithology, and aquifer characteristics, as well as groundwater movement patterns at the research point. Judging from the type of constituent rocks in the study area, it can be predicted that the types of aquifers in the study area are free aquifers, semi-depressed aquifers, and depressed aquifers, because they are between impermeable layers. The groundwater in this area is abundant and of high quality. In the research area, there are layers of sand and clayey sand, which are favourable types of aquifers. At 19 geoelectric measurement points, there are three types of soil and rock layers, namely permeable, semi-permeable, and impermeable. The analysis of resistance values identifies three types of layers: permeable layers, which consist of soil layers and sandstones; semi-permeable layers, which include sandy clay and clay sand; and impermeable layers, which are made up of clay rocks and crystalline rocks.