Effects of Seasons on Chemical Water Quality Parameters in Bakolori Reservoir

Abstract

The study was conducted in Bakolori reservoir.  In this study, some chemical water quality parameters of Bakolori reservoir in Zamfara State in north western Nigeria were assessed through standard methods.  Water samples were collected once every month and concentrations were determined in the agriculture chemical laboratory of Usmanu Danfodiyo University, Sokoto Nigeria. Data generated were analyzed seasonally and sub-seasonally using analysis of variance (ANOVA). The effects of the season on some chemical parameters recognized in this study were determined. Dissolved oxygen was highest (11.03 ± 1.65 mg/l) in late dry sub-season with overall mean of 9.50 ± 2.10mg/l. Biological oxygen demand obtained highest value of 18.68 ± 2.87 mg/l in flood sub-season and annual mean of 11.83 ± 5.30mg/l. The annual mean pH value was 7.67 ± 2.94. Conductivity was highest (196.35 ± 73.50 µS/cm) in flood sub-season with annual mean of 128.34 ± 66.49 µS/cm. The results obtained indicated that seasons affected biological oxygen demand. Conclusively, there was slight pollution by biological oxygen demand, therefore close monitoring of this parameter/element to avoid increase in its concentration was highly recommended.