Flood water hydrogeochemistry characteristics in Pindul Cave, Gunungsewu Karst Area, Indonesia

Abstract Pindul cave located in Gunungkidul Regency, Gunungsewu Karst Area, Indonesia has a unique characteristic which is dominated by surface rivers (allogenic recharge) and groundwater (autogenic recharge). The main purpose of this study to analyze temporal variation flood water hydrogeochemistry Cave. Water sampling for analysis taken the wet season three selected events. Parameters consist major dissolved element (Ca 2+ HCO 3 − ); conductivity; total solid; SI calcite; log PCO 2 ; pH. result shows that there was correlation between discharge parameters. events Cave typified low value calcium bicarbonate high CO gas content indicated dillution precipitation processes. also show negative calcite during event mean unsaturated, so it becomes aggressive towards calcite. According characteristics, conduit flow from large-fracture already developed.