et al., S. (2025). Spatial Variation in Water Quality at Karst Springs in South Malang: Geological Control and Flow Type. Egyptian Journal of Aquatic Biology and Fisheries, 29(4), 3117-3137. doi: 10.21608/ejabf.2025.449523
Susanti et al.. "Spatial Variation in Water Quality at Karst Springs in South Malang: Geological Control and Flow Type". Egyptian Journal of Aquatic Biology and Fisheries, 29, 4, 2025, 3117-3137. doi: 10.21608/ejabf.2025.449523
et al., S. (2025). 'Spatial Variation in Water Quality at Karst Springs in South Malang: Geological Control and Flow Type', Egyptian Journal of Aquatic Biology and Fisheries, 29(4), pp. 3117-3137. doi: 10.21608/ejabf.2025.449523
et al., S. Spatial Variation in Water Quality at Karst Springs in South Malang: Geological Control and Flow Type. Egyptian Journal of Aquatic Biology and Fisheries, 2025; 29(4): 3117-3137. doi: 10.21608/ejabf.2025.449523
Spatial Variation in Water Quality at Karst Springs in South Malang: Geological Control and Flow Type
The karst region of southern Malang, East Java, Indonesia, is underlain by carbonate rocks of the Wonosari and Mandalika Formations, forming a complex aquifer system shaped by dissolution processes and water–rock interactions. This study assessed spatial variations in groundwater quality at four major springs: Umbulan, Durmo, Bendo, and Sendang Biru. In situ measurements using a portable multiparameter device recorded pH values of 7.17–7.45, electrical conductivity (EC) of 604.3– 805.7μS/ cm, and total dissolved solids (TDS) of 278.3– 364.7mg/ L. Laboratory analyses showed turbidity values of 0.58–4.78 NTU and CaCO₃ concentrations of 380– 446.7mg/ L. Pearson correlation analysis revealed a positive relationship between EC and CaCO₃ (r = 0.721), highlighting the role of carbonate dissolution in controlling groundwater ionic composition. Conversely, a moderately strong negative correlation was observed between turbidity and CaCO₃ (r = –0.687). The elevated turbidity at Sendang Biru Spring suggests additional sediment input, likely linked to recharge zone disturbances. Overall, the results indicate that hydrogeochemical dynamics in the Southern Malang karst are strongly influenced by carbonate dissolution, groundwater flow path characteristics, and local anthropogenic impacts.