| Abstrak/Abstract |
This research was conducted in two main springs, namely Kalisirah and Jumbleng springs, located on the north side of the South Gombong karst area, Central Java, Indonesia. The objective of this study was to determine the temporal variation of the saturation indices with respect to the mineral calcite in the two springs. Water samples were taken 24 times at each spring during dry, rainy, and flood events. Electrical Conductivity (EC), pH, temperature, calcium (Ca2+) and bicarbonate (HCO3-) were measured directly in the field, while other major elements such as Mg2+, Na+, K+, SO42-, Cl- were analyzed in the laboratory. Furthermore, the calculation of the Saturation Indices with respect to the calcite mineral (SIcal) and carbon dioxide partial pressure (logPCO2) was carried out. The analysis results show that temporally, the SIcal value is generally higher during low discharge (dry season) and decreased during high discharge (rainy season). When compared, Jumbleng Springs has a stronger relationship between decreased discharge and an increase in SIcal. Meanwhile, the variation of SIcal increase (during the dry season) is also followed by a decrease in log PCO2, which indicates the dominance of the calcite precipitation process when the carbon dioxide content in the water is minimal. |
