One-Way ANOVA, Tukey HSD, Scheffe, Bonferroni and Holm Multiple comparison tests for Physico-chemical Parameters in Four Water Bodies of Davangere District, Karnataka

Abstract

Surface water samples were collected for physico-chemical analysis during 2016-17 from four water bodies (Hadadi lake, Gonivada lake, Lokikere lake and Shagalealla) of Davanagere district , Karnataka. The main objectives of this study is to analyse various parameters such as pH, EC, turbidity, total alkalinity, total dissolved solids, chloride, total hardness, calcium, sodium, sulphate ,nitrogen and potassium. One-way ANOVA, Tukey HSD test with Scheffe, Bonferroni and Holm multiple comparison for the water quality parameters were carried out. pH of all the four water bodies are alkaline in nature with the total hardness included under hard to very hard category. Most of the water quality parameters are highest in Shagalehalla due to the agricultural runoff from the surrounding areas and human anthropogenic activities. One Way ANOVA for physical parameters depicted “F statistic value of 52.1265 with a “P” value of 1.112. Similarly, for chemical parameters “F”value and “P” values are 29.3941 and 5.6732 respectively. The p-value consequent to the F-statistic of one-way ANOVA is lower than 0.05 level and Tukey's HSD test to each of the six pairs of water quality parameters them exhibits statistically significant difference, We Compared the outcome against drinking water quality standards as per WHO and BIS, and it is observed that water samples from these water bodies are potable for human consumption after proper treatment due to moderate levels of pollution as per the physico-chemical data. It is concluded that the physico-chemical characteristics of the water indicates that the water bodies are moderately eutrophic in nature and there is an urgent need of preventive measures.