Hydrochemical interfaces using water quality index in ascertaining integrity of river Ikpoba, South-South Nigeria

Abstract

Investigation on the quality of river water resources, management and hydro-chemical interfaces is vital for monitoring and ascertaining of surface-water contaminants sources. River Ikpoba samples were gotten from various sampling points at a distance of 10 m apart along the stretch of the river during the dry season (November 2020) and wet or rainy season (July 2021). These samples physicochemical parameters were scrutinized using and the outcome was used to compute coefficient of variability, water quality index (WQI), multivariate test as well as descriptive and L-moment statistics. The result displays that WQI of 56.2% sampling locations is categorize as excellent water in both seasons. Besides, the WQI values gotten during the scrutiny displayed deterioration changes in water quality from up-stream location to down-stream location, which in turn, signifies that river water is of poor standard or quality. Beyond, the periodic values of WQI suggest that throughout wet season, the river water is more badly influenced than during dry season. Similarly, analyses using thrice variable probability distribution model, explicitly; generalized pareto distribution (GPA); generalized extreme value distribution (GEV), as well as generalized logistics distribution (GLO) with the idea of ascertaining the appropriate fit probability/ likelihood distribution model, predicted (forecasted) rainfall quartile magnitude (Qt) created on the GLO model vary between 83.55 mm at two years (2yrs) return period to 133.68 mm at 100 years return period. Equally, r2 which is the coefficient of determination for the experimental vs. predicted (forecasted) rainfall created on the appropriate fit model was witnessed to be 0.9999.