LAUSR

The headwater stream Bal Ganga is a famous perennial, snow-fed tributary of the River Bhilangana. It emanates from the Khatling glacier and then mixed with the Dharam Ganga in Chamiyala and ultimately merges with the River Bhilangana in Muniprayag near the Ghansali town. The altitudinal gradient of Bal Ganga stream is not very high. The total basin reflects a network of various streams, rivulets of various dimensions beautifully representing a dendritic drainage or river system pattern. A total of three sites were identified for the collection of water samples in the study area. Analysis of physicochemical profile of mountain fluvial system of Bal Ganga had been undertaken for a time span of 12 months during October, 2016 to September, 2017. A total of thirteen physicochemical parameters were recorded during the study period. The water velocity was recorded between 0.47 and 2.24 m s −1 . Hydro median depth was recorded within a range of 3.14–4.89 m. Total dissolved solids were found within a range of 84.3–101.1 mg l −1 . Turbidity was found between 10.3 and 27.3 NTU. The concentration of dissolved oxygen was recorded within a range of 7.06–11.6 mg l −1 . Concentration of free CO 2 was recorded within a range between 2.2 and 13.2 mg l −1 . Concentration of chlorides was recorded within a range between 2.84 and 9.66 mg l −1 , and hardness concentration was recorded within a range of 14–28 mg l −1 . A total of 15 species from two major groups of phytoplanktons and periphytons were identified that were Cocconeis, Cymbella, Diatoma, Fragilaria, Gomphonema, Navicula, Nitzschia, Synedra, Tabellaira, Cosmarium, Ulothrix, Spirogyra, Zygnema, Chlamydomonas and Cladophora.