A groundwater tracing investigation to determine Kalisirah Karst Springs catchment area, Kebumen Regency, Central Java

Abstract

Water tracing was conducted at Karangbolong Karst as a rapid assessment of the Kalisirah spring hydrological characteristics. This study was conducted to determine the movement of underground flow and the estimation of the Catchment Area using the Todd Nomogram and field observations. The results of flow tracing tests conducted in Pocung Cave indicate that there is underground river network connectivity between Pocung Cave, Jeblosan Sinkhole and Kalisirah Springs. Based on topographic survey and flow tracing test, the calculation of the estimated area of the Kalisirah catchment area is 180 Ha. The results were also validate using other parameters, namely flowrate and rainfall in the research location using Todd Nomogram. The estimated area of the Kalisirah catchment area with the Todd Nomogram is 189.2 Ha. The calculation of the estimated area of Kalisirah catchment area based on topographic survey and water tracing is relevant with the estimated area with Todd Nomogram. Groundwater tracing investigation can be used to determine karst spring catchment area, as a preliminary study to understanding the karst hydrology.