Research
Estimating Water Availability for Agriculture in Abeokuta, South Western Nigeria
Water availability for Abeokuta, a sub humid part of Nigeria was determined using Blaney-Criddle method and applying 21 years of data on precipitation, sunshine hours, wind speed, minimum and maximum temperature and relative humidity. The water need of certain crops within the study area such as cotton, maize, pepper and tomato were derived. This was done by calculating the evapo-transpiration values for each month within the study period, estimating the growth stages of the crops, the crop factor for each growth stage, the crop factor for each of the month during the growing season, calculating the daily crop water need and the monthly crop water need. Result showed that the crop water need for the growing season of maize is 375 mm. It also showed that maize can be planted conveniently within its growing season without irrigation in Abeokuta. The result obtained for cotton showed that the crop water need for the growing season is 588 mm and that the plant could be planted during its season in the study area with irrigation. The result obtained for tomato showed that the crop water need for the growing season is 498 mm and that it can be planted conveniently within its growing season without irrigation in Abeokuta. The result obtained for pepper showed that the crop water need required for the growing season is 513 mm. It also showed that pepper can be planted conveniently within its growing season without irrigation in Abeokuta.
Impact Evaluation of Urbanization on River Ona in Eleyele Catchment, Ibadan, Nigeria
The study investigated a long-term effect of urbanization on the water quality of Ona River in Eleyele Catchment, Oyo State Southwest Nigeria. Secondary water quality data between 1979 and 2007 were collected from Eleyele’s Water Works, Ibadan. In compliment, water samples were collected from five sampling points along River Ona. Important water parameters analyzed using standard procedures were: temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), turbidity, total alkalinity, total hardness, metals (calcium, magnesium, sodium, copper, lead, cadmium, chromium, nickel, iron) and anions (nitrate, sulphate, chloride). Results showed increased concentration of nitrate and chloride and decreased dissolved oxygen level of River Ona over 28-year assessments. Present field study showed relatively high values of Pb (0.06-1.15 mg/L), Cr (0.01-1.31 mg/L), Cd (0.00-0.26 mg/L), Fe (0.40-1.96 mg/L), Ni (0.02- 0.27 mg/L) and nitrate (27.0-50.0 mg/L) compared with World Health Organization (WHO) permissible standards in drinking water. Water quality parameters were generally high between sampling point 1 and 3 due to the influx of industrial effluent from the nearby industries and indiscriminate disposal of wastes at the bank of the river.
