GROUNDWATER AND UPPER CITARUM RIVER WATER INTERACTION AND ITS RELATION TO GROUNDWATER AND RIVER WATER QUALITY AND FLOODING

• Main Author: Arifin
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/50151
• Institution: Institut Teknologi Bandung

River water contamination and flooding are the two main problems that have been known in the upper Citarum River. In general, river water has a relationship with groundwater, i.e. as a losing stream where river water fills the groundwater, or as a gaining stream where groundwater fills the river water. The interaction between groundwater and the upper Citarum River water may influence the river water contamination and flooding. To prove this, a study was conducted to analyze the interaction between them quantitatively and qualitatively, and to determine the impact of their interactions on river water and groundwater contaminations and flooding. In this study, the quantitative analysis was carried out using the couple SWAT-MODFLOW model, while the qualitative analysis was carried out by comparing the elevation of groundwater and river water table, as well as their physical and chemical parameters. Quantitatively, the groundwater and upper Citarum River water interaction in 2003 to 2019 was dominated by gaining stream, with an average amount of groundwater filled the river ranged from 0 to 1,591 m3/day. However, in certain segments, they interacted as losing stream with an average amount of river water filled the groundwater ranged from 0 to 211 m3/day. Qualitatively, the comparison between the elevation of the groundwater table and the upper Citarum River water showed that the interaction between them was dominated by gaining stream, as the elevation of the groundwater table was higher than the elevation of the river water. Besides, the interaction between them, either as losing stream or gaining stream, was shown by the physical and chemical parameters of groundwater and river water which were not much different. The groundwater and the upper Citarum River water interaction had some impacts on the river and groundwater contamination, and flooding. Since the interaction between them was dominated by gaining stream, the quality of the groundwater around the river was generally better than the quality of the river water. Moreover, the results of the SWAT-MODFLOW model showed that the contribution of groundwater to flooding was very small, i.e. 0.12 to 0.35%.