Abstract

Water quality analysis of the seven feeder rivers in Tasik Chini was carried out from October 2004 to December 2005. A total of nine sampling sites were selected in this study, namely: Sungai Datang (St.1), Sungai Cenahan (St. 2), downstream of Sungai Gumum (St. 3), mid of Sungai Gumum (St. 4), Sungai Kura-kura (St. 5), Sungai Melai (St. 6), Sungai Jemberau (St. 7), upstream of Sungai Paya Merupuk (St. 8), and downstream of Sungai Paya Merupuk (St. 9). Eleven water quality parameters were selected and analyzed in-situ and ex-situ during two sampling seasons. Laboratory analyses were carried out according to the HACH and APHA. Results of the study indicated that the pH content ranged from 3.2 to 6.32, dissolved oxygen 0.27 to 6.4 mg/L, conductivity from 14.33 to 85.7 µS/cm and temperature from 24.1 to 32.1˚C. Total dissolved solids ranged from 22.67 to 184 mg/L, total suspended solids from 1.17 to 79.11 mg/L and turbidity from 4.67 to 28.67 NTU. Nutrients such as ammonical nitrogen (0.01 to 0.57 mg/L), nitrate (0.7 to 2.9 mg/L), phosphate (from not detectable to 0.50 mg/L) and sulphate (from not detectable to 2.0 mg/L) were also studied. This showed that most of the feeder rivers have contributed to high nutrients values in Tasik Chini. Statistically, the relationship between water quality parameters were correlated as very weak and moderately correlated (R2= 0.40). Phosphate and sulphate were significantly correlated as positive slope; turbidity and nitrate showed negative slope with discharge during both the seasons (R2=0.651; R2=0.624). Recent activities such as deforestation, mining, agriculture and tourism have taken place in the surrounding areas of the lake. These activities were expected to influence the stability of the water quality of the feeder river of Tasik Chini.