Water Quality Indices (WQI) play a crucial role in assessing and monitoring water resources. The contributions of several scientists, their approaches, and methodologies are of significant importance in the development of these indices. Historically, we can analyze the works of certain scientists who had a major impact on the development of these models as follows.
Horton, R.K. (1965) developed index numbers for assessing water quality, which served as a tool for reducing water pollution. He selected 10 parameters and assigned weights that indicated the significance of each parameter. Horton's approach was a significant step in the history of WQI, providing a systematic approach to water quality assessment (Tavassoli, S., & Mohammadi, F., 2017).
Brown R.M., McClelland N.I., Deininger R.A., and Tozer R.G. (1970) developed a new WQI model. In their model, DO, coliforms, pH, temperatures, BOD, total phosphorus, and other parameters were assessed through arithmetic mean values. Later, by incorporating geometric sums, they created a more refined assessment methodology. This approach allowed for consideration of the interconnections between parameters (Casillas-García, L. F., de Anda, J., Yebra-Montes, C., Shear, H., Díaz-Vázquez, D., & Gradilla-Hernández, M. S., 2021).
Steinhart C.E., Shcierow L.J., and Sonzogni W.C. (1982) developed a new Ecological Quality Index (EQI). This index included biological, physical, chemical, and toxic parameters, providing precise and comprehensive assessment capabilities. Their work was a significant achievement in assessing water quality from an ecological perspective (Chidiac, S., El Najjar, P., Ouaini, N., El Rayess, Y., & El Azzi, D., 2023).
In the mid-1990s, a new WQI was introduced in Britain, which was later refined by the Canadian Council of Ministers of the Environment and recognized as CCME WQI. This process helped align with international standards (Hurley, T., Sadiq, R., & Mazumder, A., 2012), (Oke, A. O., Sangodoyin, A. Y., & Omodele, T., 2017), (Cash, K., & Wright, R., 2001).
Overall, these scientists and their works have led to significant developments in the field of water quality assessment and monitoring. Their approaches and methodologies are currently applied in the management and protection of water resources. The research conducted in assessing water quality is crucial for the preservation of natural and artificial ecosystems and for providing the population with ecologically clean drinking water resources.
The ability to quickly and efficiently determine water quality.
Can be used in monitoring systems to assess the quality of various water sources (groundwater, surface drinking water, as well as river and lake ecosystems), ensuring their widespread application.
WQI helps to condense large amounts of water quality data into a single value, making the results easier to understand and accelerating the decision-making process.
WQI models consist of four main stages: parameter selection, sub-index development, weight calculation, and index compilation, allowing for systematic process management and making the results more reliable.
Since each WQI model is based on local water quality standards, its results are tailored to the specific regional conditions, helping to manage local water resources effectively.
The uncertainties present in WQI models highlight the need for further improvement, which can increase the reliability of WQI models through scientific research and practical applications.
Based on these advantages, we can understand that WQI models serve as an important tool for developing measures like water quality monitoring and assessment, and water resource protection.
