Hua: Identifying the source of pollutants in Malacca River using GIS approach - 571 - IDENTIFYING THE SOURCE OF POLLUTANTS IN MALACCA RIVER USING GIS APPROACH HUA, A. K. Department of Environmental Sciences, Faculty of Environmental Studies, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia e-mail:
[email protected] (Received 19th Mar 2017; accepted 26th Jun 2017) Abstract. The study was conducted to determine the dominant source of pollutants in Malacca River using the combined methods of water sampling and GIS approach. The study was conducted in 9 sampling stations based on Malacca River sub-basins. The result of WQI indicated that station 4 and 5 are polluted; station 8 and 9 are clean; and other stations are slightly polluted. PCA identified several pollutant sources, namely agricultural, residential, industrial, animal husbandry activities, as well as sewage treatment plants. Applied GIS technique detected several areas as hotspots pollutants sources, namely agricultural activities in station 5; residential activities in station 1, 2, 5, 6, and 7; industrial activities in station 3, 4, 5, and 7; animal husbandry in station 5 and some scatterings in station 1 to 4; as well as sewage treatment plant in moderate hotspot area between station 5 and 6, respectively. Besides the recommendation to reduce the river water pollution through the control of pollutants source, this study provides crucial information for the identification of problematic areas and spatial database of Malacca River for better understanding and management of river water quality in the future, as well as a reference for future land use and urban design development purposes. Keywords: WQI, PCA, hotspot analysis, spatial database Introduction River water pollution has received great attention in recent years and continues to receive serious concern throughout the world.