Determination of Groundwater Flow Pattern in Jombang Regency, East Java, Indonesia

Abstract— Groundwater is a natural resource which moves following the hydrological cycle and its existence is hidden below the soil surface. In order to be beneficially used, the flow pattern of groundwater potential is an important aspect. Determination of groundwater flow patterns can be done by modeling. The objective of this study was to determinate the groundwater flow pattern in the study area. Modeling of groundwater flow pattern in the study area was based on the data of 70 wells scattered in Jombang regency, with variations in the depth of 50–127 m BGL on confined aquifer. Groundwater flow modeling was done using a computer program package Visual MODFLOW 2011.1 (demo version/a trial lisence). The output of the model was the groundwater flow pattern in the study area, has been calibrated by comparison of the ground water level measured by the groundwater level depiction of the model results based on criteria: correlation coefficient = 0.989, root mean square error = 2.97 m, and mean absolute percentage error = 4.75%. Groundwater flow pattern in the study area flows from areas with high topography in the Southeast section of the study area leading to an area with lower topography that is to the Northwest and to the North which is ended in the Brantas River as a natural hydrological boundaries of the study area. Keywords— Flow pattern, groundwater, Jombang regency, modeling.