Application of Water Quality Indices and Dissolved Oxygen as Indicators for River Water Classification and Urban Impact Assessment

Abstract

The usefulness of water quality indices, as the indicators of water pollution, for assessment of spatial-temporal changes and classification of river water qualities was verified. Four water quality indices were investigated: WQI (considering 18 water quality parameters), WQI(min) and WQI(m) (considering five water quality parameters: temperature, pH, DO, EC and TSS) and WQI(DO) (considering a single parameter, DO). The water quality indices WQI(min), WQI(m) and WQI(DO) could be of particular interest for the developing countries because of the minimum analytical cost involved. As a case study, water quality indices were used to evaluate spatial and temporal changes of the water quality in the Bagmati river basin (Nepal) for the study period 1999-2003. The results allowed us to determine the serious negative effects of the city urban activity on the river water quality. In the studied section of the river, the water quality index (WQI) was 71 units (classified as good) at the entry station and 47.6 units (classified as bad) at the outlet station. For the studied period, a significant decrease in water quality (mean WQI decrease = 11.6%, p = 0.042) was observed in the rural areas. A comparative analysis revealed that the urban water quality was significantly bad as compared with rural. The analysis enabled to classify the water quality stations into three groups: good water quality, medium water quality and bad water quality. WQI(min) resulted in overestimation of the water quality but with similar trend as with WQI and is useful for the periodic routine monitoring program. The correlation of WQI with WQI(min) and DO resulted two new indices WQI(m) and WQI(DO), respectively. The classification of waters based on WQI(m) and WQI(DO) coincided in 90 and 93% of the samples, respectively.

Water Quality Index as a Tool for Assessment of Status of an Urban Lake of Mumbai

“…They suggested that the latter was sufficient as much as the former in the assessment, resulting in a decrease in analytical cost, which is a limiting factor in water quality assessments. Kannel et al, (2007) also showed that the WQI min on five parameters (temperature, pH, dissolved oxygen, electrical conductivity and total dissolved solids) could be useful for the periodic routine monitoring program of urban impacts on freshwater bodies.…”

“…Surface water quality is traditionally assessed by water quality standards and objectives (Rosemond et al, 2009). However, this traditional approach cannot provide sufficient information on the overall quality of water or the spatial and temporal trends (Kannel et al, 2007). Although dynamic mathematical modelling or multivariate statistics are the best approaches to determine these trends (Boyacıoglu and Boyacıoglu, 2007), they require overmuch effort, financial resource, and expertness and they are not easily applicable or cognizable.…”

“…The WQIs are commonly used in either the classification of surface waters (Boyacıoglu, 2010;Lermontov et al, 2011) or the assessment of beneficial use (Said et al, 2004) and water pollution (Akkoyunlu and Akıner, 2012;Bakan et al, 2010;Kannel et al, 2007;Zhang and Zhang, 2007). For example, Pesce and Wunderlin (2000) calculated the objective WQI (WQI obj ) on 20 parameters and the minimum WQI (WQI min ) on three key parameters (dissolved oxygen, electrical conductivity or total dissolved solids, and turbidity) to assess the effect of urban discharge on a receiving river water quality.…”

Hydrochemical characteristics and planktonic composition assessment of River Henwal in Himalayan Region of Uttarakhand using CPI, Simpson's and Shannon-Weaver Index

“…This stream is the tributary of Holy River Ganga demonstrating water for water system, household and for different purposes. Because of number of employments, extensive waterway water quality checking program is turning into a need with a specific end goal to shield general wellbeing and to secure the profitable and powerless new water assets (Kannel, 2007;Singh, 2014).…”

Water quality analysis of River Yamuna using water quality index in the national capital territory, India (2000–2009)

“…According to StambukGiljanovic (1999), WQI is a mathematical tool which has the ability to provide a single number for the large quantities of water quality data in a comprehensive manner. Therefore, it is a simple tool for decision makers on the quality and possible uses of a given water body (Bordalo et al 2001;Cude 2001;Kannel et al 2007).…”