Abstract:
The increasing demand for freshwater has been on the increase as a result of geometric
population growth, erratic climate change and urbanization has necessitated more attention and
reliance on groundwater resources most especially in Ado-Ekiti, Nigeria. This necessitates the
urgent need for judicious management of available groundwater resources to meet the freshwater
requirements in the studied area. Geographical Information System (GIS) and Remote Sensing
(RS) techniques were used to map out the groundwater recharge potential of the studied area.
Google Earth and Land Satellite (LANDSAT) 7 sensor of Enhanced Thematic Mapper Plus
(ETM+), path 191 and row 55 were used to acquire the satellite imageries of Ado-Ekiti. Using
high resolution imageries, a Digital Elevation Model (DEM) was developed with Surfer 8 and
ArcGIS 10.0 softwares to identify areas with high, medium and low groundwater recharge zones
in the studied area. The elevation, slope, land use/ land cover, drainage density, lineament
density, lithology, flow direction, flow length and flow accumulation maps of the study area
were generated by using the DEM. The groundwater recharge potential was obtained by
overlaying all the thematic maps that affected the groundwater distribution. Each thematic map
was weighted according to its effect on groundwater infiltration. The results showed that areas
with high lineament density, long flow length, high flow accumulation, high drainage pattern,
low slope (lowland region) and vegetation have high groundwater recharge potential, and areas
with medium lineament density, flow length, flow accumulation, drainage density, slope and
sparse vegetation, respectively have moderate groundwater recharge potential while areas with
low lineament density, short flow length, low flow accumulation, low drainage density, high
slope (highland region) and sparse vegetation have low groundwater recharge potential. Better
information on groundwater recharge potential of the studied area was provided via easily read
and accessible maps generated from remotely sensed data and ArcGIS 10.0 software. The results
also revealed that geology survey should be carried out to validate the results. |
