PHYSICAL STRUCTURE

Physical Characteristics
Ogun State is located in the south-west of Nigeria It is contained within longitudes 2o45’E and 4o45’E; and latitudes 6o15’N and 7o60’N. The land area is 16,762 square kilometres.

It is bounded on the west by the Republic of Benin, to the south by Lagos State and a 20 kilometre stretch of the Atlantic Ocean, to the east by Ondo and Osun States, and to the north by Oyo State.

The topography of the State is characterised by high lands to the north and sloping downwards to the south. The highest region is in the north-west and rises to just over 300 metres above sea level. The lowest level is to the south terminating in a long chain of lagoons. The only window to the Atlantic Ocean is to the south east of the State in Ogun Waterside LGA.
With the general topography sloping from the north to the south, all the main rivers in the State flow from the north to the south. There are five major basins: the Yewa, Ogun, Ona, Osun and Sasa basins.

The geology of Ogun State is made up of the basement complex and the sedimentary layers. The basement complex is essentially non-porous and water can only be contained in the crevices of the complex. This basement complex primarily underlies

the sedimentary layers which consist of Cretaceous, Tertiary and Quaternary sediments deposited in the coastal basin.
The climate is characterised by consistently high temperature ranging between 22 and 35oC for most of the year. The south-westerly winds dominate the area between April and October bringing heavy rains and the north-easterlies dominate between November and March bringing dry dusts and harmattan haze in December and January.

With no barrier to the prevailing winds, the south westerly wind is able to penetrate deep into the State and beyond bringing a lot of rain. Given the location and climate, the primary vegetation is equatorial rain forest with large trees and dense undergrowths. With human intervention, however, a lot of the trees have been felled for commercial uses and secondary forests with smaller trees are re-emerging giving rise to derived savannah.

Location and Size
Ogun State is entirely in the tropics. Located in the Southwest Zone of Nigeria with a total land area of 16,409.26 square kilometres, it is bounded on the West by the Benin Republic, on the South by Lagos State and the Atlantic Ocean, on the East by Ondo State, and on the North by Oyo and Osun States. It is situated between Latitude 6.2°N and 7.8°N and Longitude 3.0 o E and 5.0°E.  

Climate

The climate of Ogun State follows a tropical pattern with the raining season starting about March and ending in November, followed by dry season. The mean annual rainfall varies from 128cm in the southern parts of the State to 105cm in the northern areas. The average monthly temperature ranges from 23°C in July to 32°C in February. The northern part of the State is mainly of derived Savannah vegetation, while the Central part falls in the rain forest belt. The southern part of the State has mangrove swamp.

Topography/Ecology
The geographical landscape of the State comprises extensive fertile soil suitable for agriculture, and Savannah land in the north ­ western part of the State, suitable for cattle rearing. There are also vast forest reserves, rivers, lagoons, rocks, mineral deposits and an oceanfront.