“…The use of fuzzy logic as an environmental evaluation method began in the 1990s and has been used broadly for determining trophic status and water quality indices in rivers (Lee and Chang, 2005;Chang, 2008;Lermontov et al, 2009;Semiromi et al, 2011;Ocampo-Duque et al, 2006;2013;Mourhir et al, 2014), natural lakes (Chen and Mynett, 2003;Icaga, 2007), reservoirs (Lu et al, 1999;Soyupak and Chen, 2004;Liou and Lo, 2005;Taheriyoun et al, 2010) and in evaluation of groundwater quality (Gholami et al, 2017); but none of these uses involved tropical regions. The fuzzy approach has also been used in water quality and watershed evaluations combined with other techniques, such as self-organizing maps (Lu and Lo, 2002), and geographic information system (GIS) (Pinto et al, 2016;Gholami et al, 2017).…”