GIS-based analysis of water pollution in the Cisadane river, Indonesia

The rapid growth of anthropogenic activities within the river impacts the river holistically. Cisadane River is categorized as one of the few prioritized watersheds that require conservation by the Ministry of Environment. Approximately 246 industries in Tangerang City (one of the regions that are included in the Cisadane Watershed area) are monitored by the Ministry of Environment as there is an extensive amount of toxic industrial waste disposed into the Cisadane River. This watershed is under further observation as it is progressively exposed to water quality degradation. Therefore this study aims to analyze the water quality in the Cisadane River from 2020 to 2021 based on the physical and chemical properties using the geographical information system (GIS) approach. The monitoring station was determined to represent the water quality from upstream to downstream within the dry and wet seasons. The spatial distribution of the water quality was generated into maps using ArcGIS 10.8 software. The result shows that during the dry season in 2020 and 2021, the water quality throughout all zones (headwaters to floodplains) is found to be highly contaminated. Meanwhile, during the wet season in 2020 and 2021, the water quality is highly contaminated in the headwaters zone to parts of the floodplain zone. The remaining floodplain zone had less contaminated water quality.