Adapted Water Quality Indices: Limitations and Potential for Water Quality Monitoring in Africa

Abstract

A Water Quality Index (WQI) is a tool that describes the overall water quality by combining complex and technical water quality information into a single meaningful unitless numerical value. WQIs predict water quality since they reflect the impact of multiple Water Quality Parameters (WQPs) and allow for spatial-temporal comparison of water quality status. Most African countries employ adapted WQIs by modifying the original index (or indices) and propose their concepts for evaluating the quality of surface and groundwater, which is normally accompanied by irregularities. The current review examined the process(es) involved in WQI modifications for monitoring water quality in Africa, explored associated limitations, and suggested areas for improvement. A review of 42 research articles from five databases in the last ten years (2012–2022) was conducted. The findings indicated Weighted Arithmetic (WAWQI) and the Canadian Council of Ministers of Environment (CCMEWQI) as the most adapted WQIs. However, several limitations were encountered in WQI developmental steps, mainly in parameter selection and classification schemes used for the final index value. Incorporation of biological parameters, use of less subjective statistical methods in parameter selection, and logical linguistic descriptions in classification schemes were some recommendations for remedying the limitations to register the full potential of adapted WQIs for water quality monitoring in Africa.

Assessment of the Euphrates River’s Water Quality at a Some Sites in the Iraqi Governorates of Babylon and Karbala

“…Uses the most widely used water quality characteristics to categorize the water quality according to the level of purity. Many scientists have employed the technique [10]. The weighted arithmetic index method was employed in the WQI calculation.…”

The 2nd method Parfait-Hounsinou used to determine the overall water quality

“…The 2nd Parfait-Hounsinou method is new and is superior to the water quality index that has been used to date because it is more accurate, provides the public with more comprehensive information on water quality, and is constantly applicable across the globe [14] .…”

Spatiotemporal pattern of coastal water pollution and its driving factors: implications for improving water environment along Hainan Island, China

“…The WFD and other similar frameworks for water quality management rely mostly on collected datasets to assess water quality. In recent years, many tools and techniques have been developed to assess water quality, the water quality index (WQI) models are one of the most widely used tools ( Sun et al, 2016 ; Sutadian et al, 2018 ; Uddin et al, 2020 , 2022 , 2023a , b ; Lukhabi et al, 2023 ). WQI is a tool that describes the overall water quality by converting available water quality parameter data into a single unitless number by mathematical algorithms ( Horton, 1965 ).…”

“…WQI is a tool that describes the overall water quality by converting available water quality parameter data into a single unitless number by mathematical algorithms ( Horton, 1965 ). The method is relatively easy to apply and its results are easy to interpret by both professionals and nonexperts ( Uddin et al, 2021 ; Lukhabi et al, 2023 ). WQI allows water quality status to be compared across time and space, thus directly communicating information of water quality to the public and decision makers ( Poonam et al, 2013 ; Lukhabi et al, 2023 ).…”