ANNOUNCEMENTS
The historical data (for seven parameters over 17 years: 2003-2019 at 23 stations) for the Krishna basin in Karnataka was analysed for spatial-temporal variation, identification of ―critical clusters‖ (on the basis of ―violations of water quality parameters‖) and distribution of extreme values for DO for the critical stations identified. These were accomplished by ―Mann-Kendall‘s test, Kruskal Wallis test, Cluster analysis and Gumbel‘s distribution‖ respectively. It was found that 22 out of 23 stations showed significant trends for at least one parameter. Spatial variability for five parameters was found along the stretch of the Krishna River in Karnataka. The cluster analysis identified six stations to be critical, four of which were on the Bhima. The EVT analysis for the distribution of DO across the critical stations was found for return periods of 20, 25 and 30 years. The study reveals the underlying pattern of ―water quality across the basin‖, the trends in the ―spatial and temporal variations‖ and also serves as a tool for prediction of extreme values of parameters.
Key words: Kruskal Wallis test, Mann – Kendall test, violation matrix, Gumbel‘s distribution and cluster analysis.
