Hydrogeology Of Nsukka Southeast, – A Preliminary Approach To Water Resources Development

摘要

The hydrogeology of Nsukka SE has been carried out as a preliminary approach to water resources development of the region. Topographic, maps, data from meteorological stations, and other departments, Geological maps, aerial photograph, fracture maps and satellite images of Anambra drainage basin were employed in the study. Inorganic analysis were und ertaken using Atomic absorption spectroscophy, spectrophotometer, flame photometer, spekker absorption meter and turbimetric methods, while organic analysis was done using the most probable number Techniq ue (MPN). The result shows that the average precipitation of the area is 2.09 x 10 8 m 3 a year, while the rainfall intensity gives 0.15/year. Runoff for the area was calculated to be 1.06 x 10 7 m 3 / year, amounting to 5.07% of the total precipitation. Potential evapotranspiration amounts to 1057.98mm/year giving 8.112% of the water available from precipitation. Depth to water table ranges from 106.70m to 9.15 from recharge area of the watershed to the farmland discharge low lying area. Aquifer type ranges from unconfined , semiconfined to confined. The average transmissivity values was calculated to be 3.25 x 10 -2 m 2 /s, while hydraulic conductivity gives 2.3 x 10 -3 m/hr. Specific discharge is 2.24 x 10 -4 m/yr, average groundwater linear velocity is 4.98 x 10 -4 m/yr. The chemical constituents of deep and shallow aquifer waters show that iron concentration is on the high side. The deep aquifer waters sho w no pathogens while the shallow aquifers of the low lying discharge environment show heavy coliform presence. The water class for deep aquifer indicat es magnesium and a no dominant anion and plotted on a transition between salt and fresh water, while the shallow aquifer water is Magnesium su lp hate ( hard water) and plots within the zone of salt water. The water meets the consumption standard, and industrial needs though acidic and of high iron content. The water is excellen t for irrigation, and requires minor treatment. These information are ideal for reference during the water resources development of the region