Optimization for Engineering Problems

6Water Quality Index: is it Possible to Measure with Fuzzy Logic?

6.1. Introduction

Water is an essential resource for the survival of living beings on our planet. The excessive use and disproportionate pollution of water can make the planet’s environmental resources scarce in the future. The World Health Organization (WHO) estimates that currently about 1.1 billion people worldwide consume contaminated water (Wu et al. 2018). The water supply crisis was identified as the main risk of our current times by the World Economic Forum (2015).

Although the analysis of water quality has gained prominence over the last three decades, the concept in its most rudimentary form was first introduced more than 170 years ago, in 1848, in Germany, where the presence or absence of certain organisms in water was used as an aptitude indicator (Abbasi et al. 2012).

Unlike the quantity of water, which can be expressed in precise terms, water quality is a multi-parameter attribute. The water quality assessment depends mainly on the aggregation of information on water quality parameters at different times and places, this information being processed and culminating in a scoring scale that could be represented by an index (Terrado et al. 2010).

Many water quality indices have been formulated around the world, such as the United States National Sanitation Foundation Water Quality Index – NSFWQI (Brown et al. 1970), the Canadian Council of Ministers of the Environment Water Quality Index – CCMEWQI ...