Application of Improved Set Pair Analysis Model for Evaluation of Lake Eutrophication

Based on characteristics of lake eutrophication, total phosphorus (TP), total nitrogen (TN), chemical oxygen demand(COD_Mn), secchi disk depth (SD) and biomass (BIO) were chosen as evaluation indexes. Aiming at the problem being too complex for the present evaluation methods on lake eutrophication, a new method, improved set pair analysis model was used to solve the complicated non-linear relation between the evaluation factors and water quality grade. The model was applied to evaluate lake eutrophication of eight Lakes in China and the results of the assessment are in concordance with other evaluation methods. Compared with the other evaluation method, this model is perfect, the evaluating result is more reasonable and its resolving power is higher. Thus, a simple and effective evaluation method is provided for lake eutrophication evaluation.