A New Statistical Perspective on Trophic Indexes for Shallow Lakes

Abstract

The aim of this study is to develop a new trophic level index using water quality parameters which are known to affect eutrophication but not in national and international standards used for trophic classification and to demonstrate the applicability of index. For this purpose, water quality variables obtained from shallow lakes were statistically analyzed by using principal component analysis (PCA) and multiple linear regression analysis (MLR). The variables used in the PCA and MLR analyzes (Mn, SiO2, TN) were added to the Carlson (1977) index step by step according to the TSI (Chl-a) empirical equation to develop a new index. Also TP and TN variables present in the indices were included in the model and the Chl-a expression ratio of all variables was defined as 88%. A new trophic level index was developed by taking into account the parameters affecting the eutrophication and the degree of effect. To reinterpret and evaluate some changes in existing indices allow trophic index evaluation results to be more reliable trophic status. This new index, which was developed for the stated purposes, is expected to provide a new perspective and contribute to the improvement studies and literature.