**2. Flat terrain**

The geomorphology of an area is defined by its landforms. The landform could be made up of hills, valleys, lowlands and/or flood plains. The aerial disposition of these land features manifest as the topography of the area. That means, the topography or, in other words, the terrain of an area can be undulating, hilly, steep, gentle or flat.It is the topography of a place that determines its natural drainage pattern and this may

guide the networking of man made or engineered drainage systems. However, man can alter, to some extent, the existing natural landforms to fit into his developmental objectives.

A flat terrain is a land form with slopes not steeper than 2% [2, 3]. This type of terrain can occur within a region of greater relief such as hills and mountains or in an undulating or alluvial plain. It can also occur on top of a table land forming an escarpment.

The main characteristic of a flat terrain is water logging after a rainfall. In this regard surface runoff remains within the surrounding since there is no sufficient hydraulic head, amidst other obstructions, to drive the flow along. In which case natural drainage is restricted and flooding becomes overwhelming as long as there is a continuous rainfall. This is apparent during the rainy season.

Human settlement is often attracted to flat terrain, probably because the land would not be subjected to pronounced erosion of the soils, agricultural practice is sustainable and existential construction activities are easier to manage. Particularly, road construction on a flat terrain requires minimal earth cutting and earth embankment.
