Application of Remote Sensing Technology and GIS for Extraction of Groundwater Potential Zone Parameters in Gesing Watershed, Purworejo

Abstract

The increase in the number of residents and the long dry season is the cause of the increasing need for clean water in several areas in the Purworejo regency, one of which is the Gesing river basin area. Therefore, information is needed related to the potential of groundwater in the Gesing watershed, Purworejo district. This study has three objectives, namely: assessing the ability of remote sensing imagery (Sentinel 2A and TerraSAR-X) in extracting land parameters that affect groundwater potential, mapping groundwater potential zones using remote sensing data with geographic information systems in the Gesing watershed, and evaluating the results mapping groundwater potential zones to determine the most influential parameters on groundwater availability in the Gesing sub-watershed Purworejo district. The accuracy of the interpretation results is done by using the confusion matrix method. Spatial modeling uses a quantitative approach weighted with weighted parameters. The weight of each physic parameter is obtained from the Analytical Hierarchy Process (AHP) method. The results showed the accuracy of interpretation of lithology and land use respectively by 93% and 87%. The results of the mapping show that there are 4 classifications of groundwater potential in the Gesing sub-watershed, namely less, medium, good, and very good has and accuracy of 87%. The parameter which greatly influences groundwater potential in the Gesing sub-watershed with a weight value of 0.49 is the aquifer characteristic. While the parameter that has the least effect is drainage density which has a weight value of 0.05.