HYDROCHEMICAL AND BIOLOGICAL CHARACTERISTICS OF THREE HIGH ALTITUDINAL TROPICAL RESERVOIRS OF WESTERN GHATS, SOUTH INDIA, WITH SPECIAL REFERENCE TO POTABILITY

Saranya. P, Krishnakumar. A, Anoop Krishnan. K

Abstract: Western Ghats, being one of the biological hot spots, has always been critical for a host of natural resources, particularly for water and biodiversity, and thus serves as an important bio-geo-asset. A number of reservoirs are located in Western Ghats in and around the catchment areas of various rivers. Reservoirs are extremely important due to the role they play in generating hydroelectric power, fish production, irrigation and as a source of drinking water. Physico-chemical characteristics of water and its relationship to the diversity of phytoplanktons, were studied in three major reservoirs of Western Ghats; namely Mullaperiyar Dam, Gavi Dam and Pamba Dam. 18 species falling in 3 divisions of phytoplanktons were found. The greatest number of species were noted in division Chlorophyceae followed by Bacillariophyceae (Diatoms). The abundance of diatoms was well explained by the higher loading of silicates (77.92, 81.02, and 74.2 mg/l) while other nutrients were very low in the reservoir waters. Chlorophyll contents of the respective reservoirs were very low (0.18, 0.014 and 0.167 mg/l) indicating the oligotrophic nature of reservoirs and justified by the low nutrient status (Nitrite= BDL in all reservoirs, Phosphate= 0.091 mg/l, 0.567mg/l, 0.299 mg/l and Sulphate 78.9mg/l, 111.1 mg/l, 98.1 mg/l in Mullaperiyar, Gavi and Pamba Dams respectively). Water qualities of reservoir waters were assessed against the drinking standards and found that silicate content and E.coli counts were high in all reservoirs. The presence of phytoplanktons tolerant to organic pollution were identified using Palmer’s diversity index and the pollution status of the reservoir waters were estimated using Shannon and Weaver’s diversity index

Keywords: Reservoirs, Water Quality, Phytoplanktons

DOI: https://doi.org/10.15623/ijret.2016.0530004