Seasonal Physico-Chemistry of Lower River Benune, NIGERIA

River Benue has been greatly impacted by seasonal variations and human activities on the fadama areas bordering the river. This research assessed the impact of seasonality and riparian activities on some crucial water quality variables of River Benue. Water samples were collected at 3 points on the river course in Makurdi fortnightly for a period of 12 months (April 2010 – May 2011). The means of water quality variables in the rainy season: temperature (26.24 + 0.170 oC); pH (6.66 + 0.083); turbidity (4.579 + 0.220 NTU); dissolved oxygen (5.93 + 0.128 Mgl-1); total dissolved solids (41.34 + 1.970 Mgl-1); nitrate (1.320 + 0.084 Mgl-1) and phosphate (1.140 + 0.065 Mgl-1) varied significantly (P < 0.05), with those of the dry season: temperature (26.70 + 0.366 oC), pH (7.03 + 0.053); turbidity (1.483 + 0.369 NTU); dissolved oxygen (5.30 + 0.122 Mgl-1): total dissolved solids (32.3 + 1.660 Mgl-1). Apart from pH, all the variables also varied significantly across stations with B being significantly higher. All the parameters correlated significantly with each other except temperature and pH (rs = 0.071); temperature and turbidity (rs = 0.130); temperature and phosphate (rs = 0.010); TDS and phosphate (rs = -0.061) and nitrate and phosphate (rs = 0.103).