Analysis of underground river network connectivity in Barat Cave, Karst Karangbolong, Central Java, using the Artificial Tracer Test Method

The connectivity of the Barat Cave underground river system needs to be known support implementation proper environmental management so that water resources can maintained sustainably. However, mapping paths is often hindered by conditions narrow cave passages, a barrier blocking flow (siphon), deep lakes, waterfalls, as well filled with water. This research was conducted in Cave, Karangbolong Karst Area. purpose this study determine upstream-downstream and define characteristics passageway based on quantitative analysis transport parameters from tracer test results. network done because previous has never analyzed network. method used divided into three stages, namely pre-field stage, field post-field stage. step includes determining location study, collecting secondary data, studying literature. stage consists hydrogeological survey find information presence caves, springs, sinking stream ponors, or luweng area, instantaneous discharge measurements, tests. data processing analysis. results showed originated Kalimas stream, Mblabak Pendok Pagilangan streams, then merged single tunnel without breaker Pengantin appeared Kalikarak springs become surface river, pattern form curvilinear branchwork. for tracing have an advection value 86.528 m/hour, dispersion 0.092 m 2 /second, dispersivity 3.38 meters, recovery 63%. parameter influenced conditions.