Application of GIS in Water Management of Eleyele Catchment, South-Western Nigeria

Eleyele dam has drastically reduced in capacity since its inception in 1942. There are frequent flood incidences within the dam catchment area- noteworthy of them is the August, 2011 flood incidence. This research studies the hydrological condition of Eleyele catchment through the use of Geographic Information System. The topographical maps, digital elevation measurement maps (DEM) and hydrological maps of the Eleyele catchment were produced through GIS watershed delineation process for the year 1967 and year 2014.The results show that there is an average lowering of elevation of about 14.63m within the catchment which has greatly affected the hydrological pattern of the catchment. The Triangulated Irregular Network (TIN) of the catchment was used to produce flood risk map. The map showed that 25.24% of the catchment is prone to flooding. The study showed that there is a change in topography of Eleyele Catchment within the period studied. This is due to the urbanization of the area. Keywords : Eleyele Dam, Flood Incidences, Hydrological Condition, GIS, Watershed Delineation Process, Triangulated Irregular Network