EXOGENIC PROCESSES – ADVANCED PHYSICAL GEOGRAPHY
EXOGENIC FORCES (PROCESSES)
There are forces and processes of landforms formation. They operate on the earth’s surface. They are subcategorized into denudation and depositional processes, hence leading different landforms.
Denudational processes: These are three types i.e weathering, erosion, and mass wasting. They lead to the development of various landforms. Examples; exfoliation domes, caves, and mudflow respectively.
Where as Depositional processes: These leads to the depositional of materials after have been transported by natural agents like ice, waves, winds, and river. These leads to the formation of various landforms depending on the agents of deposition involved i.e river deposition, glacier deposition, wind deposition, and wave (marine) deposition. Examples of depositional landforms includes delta, esker, barchans, and spit respectively.
DENUDATION
Refers to all exogenic processes that lead to the breaking, wearing away and lowering of the land surface.
The term denudation was derived from Latin word “Denudare” which means to “strip bare” or “uncover” or “remove”.
Denudation include the combined effects of land sculpturing process i.e Weathering, Mass wasting, and Erosion. Transport is crucial process in denudation because its caries away materials from one place to another. The transporting agencies are water (river), waves (marine), glacier (ice), and winds.
The process of denudation operates at or very close on the earth surface. They wear down highlands to almost uniformly flat landscape where there are no hills and valleys i.e peneplains.
FACTORS DETERMINING NATURE, RATE AND SPEED OF DENUDATION PROCESSES
(i.e. weathering, Erosion and Mass wasting)
1. Nature of the rock i.e. soft rocks are more prone to denudation
2. Climatic factor i.e water and temperature facilitates denudation process
3. Vegetation cover i.e plants roots can penetrate to rocks hence easy denudation
4. Human influences i.e exposes rock to these agents of erosion
5. Relief factor i.e. steep slopes is more affected than gentle slope.
5. Existence of living organism i.e can facilitate decaying of rocks eg. Fungi
STEPS / STAGES OF DENUDATION
There are three (3) stages or steps of denudation. These are: –
- Weathering.
- Mass wasting.
- Erosion.
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