Multivariate Modelling of Water Quality Parameters in Nigeria

Abstract

Water is a unique substance that has many physical properties distinct from those possessed by other liquid, gaseous, or solid materials existing on the earth’s surface. Water is colourless and transparent substance which is not distributed uniformly over the surface of the earth, as some areas are blessed with a fairly uniform and more than adequate supply for human needs, while many other regions have a greater need for water than they can supply. Water is essential for the existence of all life forms; it is a vital need that man cannot survive without it. water is life and its importance in the life of man, animals and plants cannot be overemphasized. However, the task of meeting domestic water needs in rural and urban areas in most developing countries, particularly in Nigeria, is enormous and falls mainly to women and children. Households also spend considerable time and effort fetching water from sources such as rivers, streams, ponds, wells and boreholes. The most important fresh water resources are rivers (Kolawole et al. 2011). Rivers play a basic role in assimilating the urban waste water, industrial wastes and surface run off from agricultural fields (Basu and Lokesh 2014). Human being and other living organisms depend on water for their survival.Quality of different water resources is subjected to ongoing consequences of water pollution and these results in the increase in demand for monitoring its quality. Water is considered polluted if some substances or condition is present to such a degree that the water cannot be used for a specific purpose (W.H.O., 2017). If the concentration of substances naturally present in water increases then also the water is said to be polluted. Olaniran (1995) defined water pollution to be the presence of excessive amounts of a hazard (pollutants) in water of water quantity in such a way that it is no long suitable for drinking, bathing, cooking or other uses. Testing of the water quality is an essential part of environmental monitoring. The aquatic life as well as surrounding ecosystem is affected when water quality is poor. The quality must be tested with different physico-chemical parameters and the selection of parameter for testing Abstract: Inadequate safe water remains a threat to human health in Ibadan Metropolis of Oyo State, Nigeria. The Asejire reservoir is considered a major source of water in Ibadan and water pollution is pronounced as a result of growing population and urbanization in the area it serves. In this study, We studied and analysed water quality parameters of treated and untreated water samples from Asejire Reservoir of Oyo state, Nigeria. We examined the conformance of the sample parameters to the W.H.O 2017 standards for safe and acceptable drinking water parameters. Data were obtained from the Oyo State water corporation which contained values on water quality parameters such as turbidity, colour, pH, alkalinity, etc. Correlations between values of the pollutants were examined for collinearity before estimating linear discriminant functions (LD) that helped to classify water samples into any of “safe and acceptable”, “safe but unacceptable”, “unsafe yet acceptable” and “unsafe and unacceptable”. The estimated discriminant function had a efficiency of up to 84.3% in correctly predicting the class of water sample based on “appearance”, “colour”, “turbidity”, “taste and odour”, “alkalinity”, “hardness”, “chloride”, “iron”, “manganese” and “total dissolved solids”. Results also showed that of all the 41 water samples which were regarded as final and ready for distribution; 7.3% were potentially unsafe and unacceptable for consumption as they were either polluted with iron or dissolved solids from domestic, industrial, agricultural wastes, insecticides and pesticides.