Author(s)

Ruei-Shan Lu, Jin-Yiao Hu & Shang-Lien Lo

Abstract

A general methodology for fuzzy synthetic evaluation is developed and illustrated with a case study of trophic status assessment for Fei-Tsui Reservoir in Taiwan. The historical data base was collected from the management agency of Fei-Tsui Reservoir from 1987 to 1995. The results of this investigation show that the long-term change of water quality and the overturn phenomena cannot be observed with the Carlson index from 1987 to 1992 but is expressed by fuzzy synthetic evaluation. Fuzzy synthetic evaluation is better suited than the Carlson index to rating the trophic status of self-sustaining lakes. Introduction The trophic state index is often based on total phosphorous (TP) concentration, chlorophyll a (chl a) concentration, and Secchi disk depth (SD). Of these three factors, chl a plays the most important role, fo

Keywords