Plateaux are elevated uplands with extensive level surface usually descending steeply to the surrounding lowlands. They are subjected to erosional process.
Plateaux may be divided into three groups according to the mode of their formation and physical appearance.
The three types are;
1.) Tectonic Plateaux
2.) Volcanic Plateaux
3.) Dissected Plateaux
What are Tectonic Plateaux?
These are formed by earth’s movement which causes uplift and uniformed altitude. Examples of tectonic Plateaux include the continental blocks of India, Meseta of Central Iberia and Harz of Germany.
When Tectonic Plateaux are enclosed by fold mountains, they are known as ‘Intermont plateaux”.
Intermont plateaux are the most extensive plateaux in the world. An example is the Tibetan Plateau between the Himalaya and Kunlum.
What are Volcanic Plateaux?
These types of plateaux results from the accusation of lava. Some well known Volcanic Plateaux are the Antrim Plateau of Northern Ireland, North Western part of Deccan Plateau, Indian and the Columbia-Snake Plateau in USA.
What are Dissected Plateaux?
Dissected Plateaux are formed from uplands that have been dissected by various agents of denudation. Example is the Scottish Highlands Britain.
Vertical erosion is the dominant action of some rivers taat cross a plateau. These rivers carve out deep valleys which break up the plateaux surface into many steep- sided pieces. A plateau formed from this action is referred to as a “Dissected Plateau”. The edges of the Jos Plateau (Nigeria) and the Futa Jalon Highland (Guinea) have been dissected this way.
Importance or Uses of Plateaux
Some of the importance are;
1.) Plateaux are good for agricultural purposes especially farming due to their cold climate and soil fertility.
2.) Since they are tableland, plateaux greatly support human settlement. For example, people live Jos Plateau (Nigeria).
3.) Some plateaux (like the Jos Plateau in Nigeria, Kosciusko Plateau in South of Canberra located in Australia) are rich in mineral resources like coal, iron, gold, lead, copper, tin,etc.
4.) Plateaux (such as Mambila plateau in Gembu, Taraba State located in Nigeria) provide a fertile grazing land for animals such as cattle, sheep, goat as they support the growth of grasses for pasturing.
5.) Tourism can extensively be carried out in some plateaux.
6.) Some plateaux are good for electricity generation around their edges.
7.) Plateaux usually provide microclimate suitable for human dwelling or settlement. For example, Jos Plateau in Nigeria.
Disadvantages of Plateaux
Some of the disadvantages of plateaux are;
1.) Some plateaux are inaccessible as that are surrounded by escarpment and mountains which serve as obstacles to the construction of roads, railways and airports.
2.) Most of the plateaux of the world are dry because of the absence of rain as winds lose their moisture before getting to the plateaux.