Assessment of anthropogenic activities impacts on the water quality of Asa river: A case study of Amilengbe area, Ilorin, Kwara state, Nigeria

Abstract

The study assessed the impacts of anthropogenic activities on the water quality of the Asa River within the case study area and the probable use of this river for agricultural purposes by estimating the Water Quality Index (WQI). Two sampling points were selected namely; upstream (A) and downstream (B). A total number of sixteen (16) samples were taken for four months (i.e two samples per month per sampling point). Temperatures were measured in-situ while other physicochemical and microbial parameters tests were conducted in the laboratory. The errors arising from environmental conditions were minimized by conducting the tests as soon as the samples were collected and the results were analyzed using both the descriptive and the inferential statistics (Pearson Correlation) on both Statistical Package for the Social Sciences (SPSS) and Microsoft Excel. This study has revealed that the Asa River within the study area is polluted as a result of the impacts of the anthropogenic activities when the results of the analyzed water quality parameters downstream are significantly (p < 0.05, at a 95% confidence interval) higher than at the upstream except for pH, DO, BOD, and EC which are relatively higher at the upstream although the study indicated that the results were within the recommendations. This study recommends that the anthropogenic activities within this area be monitored as the urbanizations are rapidly taking place and the effects are polluting the water which is making it harmful not only to the ecosystems but also making unfit for possible drinking at the downstream. Also, the study has concluded that the changes in the Land Use Land Cover (LULC) 2016 – 2020 have no statistically significant effects on the physicochemical and microbial water quality of the Asa River. Therefore, as investigated by estimating the WQI, in its current form, the Asa River is fit for agricultural purposes (irrigation farming). However, this study recommended the treatment of this water before drinking as the water in its present form is unfit for drinking.