| Abstrak/Abstract |
. In Bantul, Southern Yogyakarta, groundwater is the main source of domestic water
needs. Therefore, knowing the hydrogeochemistry of groundwater is crucial in order to manage
a sustainable groundwater resource. To characterize the compelling geochemical processes that
control the groundwater chemistry, further hydrogeochemical examinations were directed in the
area. Thirty groundwater samples were collected from shallow dug wells during the early dry
season (April 2021). Sampling procedures and chemical analysis were carried out as per standard
methods with secondary data obtained in 2006. The geochemical evaluations were depicted
using several graphical plots dependent on the ionic constituents, hydrochemical facies, and
controlling factors of groundwater quality. Two major hydrochemical facies were identified:
alkaline-earth water with higher alkali; bicarbonate predominated (62%) and alkaline-earth water;
bicarbonate predominated (32%). Weathering of silicate minerals occurs in 70% of recent
samples and predominantly regulates major ion chemistry such as calcium, magnesium, sodium,
and potassium. Chloro-alkaline indices 1,2 values signify that there are two potential rock-water
interaction processes in the study region, namely the ion exchange and reverse ion exchange.
Concentrations of nitrate, sulfate, and chloride indicate that the water chemistry has not been
heavily contaminated by the land use in the area and is still mainly controlled by geogenic
processes rather than anthropogenic activities. |
