Water Quality and Planktonic Composition of River Henwal (India) Using Comprehensive Pollution Index and Biotic-Indices

The study was conducted to assess the seasonal water quality of four stations located along the River Henwal (one of the major tributaries of River Ganga, flows in the region of Uttarakhand, India). To assess the pollution load, comprehensive pollution index (CPI) was used by considering the most significant water quality parameters for which a standard permissible limit is proposed by different government agencies. The minimum value of CPI (1.25) was observed at control site during winter and maximum (8.52) was at Jajal during monsoon which indicates that control site was moderately polluted followed by severely polluted Nagni, Kharee and Jajal. The river water was dominated by a group of blue-green algae among phytoplankton and protozoans dominate zooplankton. Besides this, Simpson’s index (D) and Shannon–Wiener index (H) were used to observe the diversity of plankton and Taxon Evenness (E) was also estimated to know the distribution of individuals within a community. The high value of D (4.69), H (1.57) and E (0.45) was found to be for Nagni site. The relationship between abiotic properties of water and planktonic composition was developed with the help of Karl Pearson’s correlation matrix. For the identification of main responsible water quality parameters and the influencing sources, PCA and CA were used. The quality of river water is declining as a result of developmental activities, and this work is expected to give the essential support to future water management systems in the area.