Author(s): Shin Ying Ang, Hin Lee Lee
Linked Author(s): Shin Ying Ang
Keywords: Tropical urban lake, seasonal water quality, eutrophication, limnetic and littoral zone, trophic state index (TSI)
Abstract: Urban lakes in Malaysia have undergone changes due to urbanization and caused significant deterioration in environment, particularly water quality. This paper is aimed to evaluate the seasonal water quality characteristic of Ampang Hilir Lake, a tropical urban man-made lake in Kuala Lumpur, Peninsular Malaysia. The lake gets its water from rainfall and culvert systems linked to the lakes from the surrounding catchment. Ex-situ and in-situ data collection was performed between November 2014 and July 2015 consisting of Northeast monsoon (wet season), inter-monsoon (April-May) and Southwest monsoon (dry season) seasons at the limnetic and littoral zone of the lake. Water quality of the lake is the worst during Southwest monsoon season compared to inter-monsoon and Northeast monsoon season as rainfall is lower during Southwest monsoon. Water Quality Index (WQI) was Class III at the limnetic zone and Class V at the littoral zone during the dry season. Biological Oxygen Demand (BOD) is at Class V (> 12 mg/l) for both zones during Southwest monsoon season indicating high organic compound in the lake. Chemical Oxygen Demand (COD) was at Class III and Class V at the limnetic and littoral zone, respectively. Ammonia Nitrogen (AN) which is toxic to aquatic life was at Class IV with values of 2. 10 � 0. 54 mg/l and 1. 67 � 0. 67 mg/l at the limnetic and littoral zone, respectively during dry season. Orthophosphate (OP) which can be absorbed by plants directly, was detected high during inter-monsoon with value of 1, 303. 33 � 228. 08 �g/l at limnetic zone and 1, 203. 33 � 218. 53 �g/l at littoral zone. Carlson's Trophic State Index (TSI) revealed that this lake was eutrophic-hypereutrophic with thick layer of algae on the lake surface especially the littoral zone. Systematic lake catchment management plan is necessary to control the pollutant loadings and hydrological runoff within the catchment area
Year: 2017