Seasonal and Spatial Variations in PhysicoChemical Water Quality of Osun River, Southwest Nigeria at some of its Natural Points

Spatial and seasonal variations in the physicochemical parameters of water quality of a tropical reservoir, Nigeria

“…The result also showed that the conductivity mean value of water in the reservoir was higher during the rainy season than in the dry season (P>0.05). The conductivity result of this study slightly differs from what was recorded by (Omoniyi et al, 2017) for natural points of the Osun River where conductivity decreases down the three reaches of the river in the dry season. However, palm oil processing effluents very close to the upstream portion of the reservoir by the riparian farmers during the rainy season and anthropogenic activities around the downstream portion of the reservoir probably contributed to the elevated conductivity values recorded during the period of study.…”

“…Other physical parameters; transparency, depth, turbidity, true colour (P>0.05), and apparent colour (P<0.05), have higher mean values in the rainy season than in the dry season (Table 3). Similar observations on the turbidity and colour of some other tropical water bodies were made by Omoniyi et al (2017), Adebisi (1981, Ikomi et al (2003) and Idowu et al (2013) which was attributed to the influx of inorganic and organic materials from over land run-off during the rainy season than that of the dry season. However, contrast to their observations was the fact that the mean water clarity (transparency) was slightly higher in the rainy season than in the dry season, this could be as a result of the Statistical influence of the sample sizes obtained in both seasons (dry season: n = 51; rainy season: n = 103).…”

“…Conductivity is a measure of the ability of water to conduct electric current, and it is sensitive to variations in the concentration of dissolved solids, mostly mineral salts. The degree of dissociation of these solids into ions, the valency of each ion, ion mobility, and water temperature all have an influence on conductivity (Omoniyi et al, 2017). The conductivity mean value of water in Esa-Odo Reservoir during this study was the highest in the upstream region followed by the downstream and lowest in the midstream portion of the reservoir.…”

“…The relative rates of respiration and photosynthesis within the pond determine whether there is a net addition or removal of carbon dioxide, and, therefore, whether pH falls or rises (Craig and Louis, 2008). Acidification of water recorded during the dry season could be attributed to increased metabolism, elevated microbial degradation of organic debris and concentrated dissolved solids in warmer water during this period (Rajasegar, 2003;Tukura et al, 2012;Omoniyi et al, 2017).…”

“…Biological processes and some anthropogenic activities have been reported by Omoniyi et al (2017) to influence river water and impoundments both in quantity and in quality, with physical and chemical quality parameters being mostly impacted by human activities. Bagenal and Braum (1978) reported that the physical and chemical properties of water bodies impact the species composition, abundance, productivity and physiological condition of aquatic organisms.…”