Determining recharge groundwater using delineation of morphological surface in Ligarmukti karst area Bogor Regency

Abstract

Abstract The Ligarmukti area is one part of the Klapanunggal karst hills in Bogor Regency. This area relies on springs as the fulfillment of raw water. It is feared that the limestone mining process in this area will damage groundwater recharge areas. This research was conducted to determine groundwater catchment areas in the Ligarmukti karst area. The method used is the morphological lineament delineation analysis of SRTM imagery compiled with the results of investigations in the field. Based on the results of delineation, the SRTM image was able to detect 76 alignment patterns in the direction of N 28° - 235° E. The fracture location was mostly located at elevation 280 - 700 m. The difference in direction of the alignment pattern is not too far away, so it is interpreted that the groundwater recharge pattern in the secondary porosity is derived from an aquifer system. The main catchment zone is at an altitude of 440-700 m above sea level in the hills with limestone constituent Klapanunggal Formation. The infiltration system in this area is an autogenic recharge, ie the recharge occurs in areas with relatively homogeneous rocks in the form of karst rocks and rainwater which is directly infiltrated in the area. This condition can be seen from the fluctuation of discharge during the rainy and dry seasons. Watershed conservation must be carried out to maintain the availability of springs by minimizing the limestone mining process in hilly areas.