Both descriptive and inferential data were analyzed, using Statistical Package for the Social Sciences, (SPSS) version 16.0 and Microsoft Excel 2007. The Wilcoxon Signed-Ranked test was performed to compare the significance of diversity between post-monsoon and pre-monsoon. The Kruskal Wallis test was conducted and compared the diversity indices (Shannon diversity, richness, evenness) and density among the streams. Kendall’s tau was performed to find the relationship between environmental variables and diversity indices. ArcGIS 9.3.1 was used for generating the map of the study area. The Shannon Diversity Index (H’ = - ΣPi * Ln Pi), the Margalef’s Index, species richness and evenness were calculated for the macroinvertebrate diversity in each reach. Evenness (E)=H/( Ln S) where, H’ = Shannon diversity index, and S = number of species in the sample. Richness (D) =S/٧N where, S = number of species in the sample, N = number of individuals in the sample. Increasingly Shannon Diversity Index has been largely used by the ecologist. However, some critics have described it as a questionable index. This is because H’ does not reflect dominant/rare community composition and ranges of limits,; particularly sample sizes are not clearly defined.

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