The Causes And Processs Of The Fluvial Processes

INTRODUCTION

This essay looks at the fluvial processes.

Fluvial comes from the Latin word fluvius which means river (Soanes) (CCSU). Hence the term is used to describe those processes involving rivers (fluvial processes) and their physical interaction interactions.

Basically there are three (3) fluvial processes:

1. Erosion

2. (Sediment) Transportation/Motion of Sediment

3. Deposition (University of California, 2008). Erosion

Erosion is the process by which the products of weathering are transported, in this case by water or rather streams or rivers (Sager, Ramsey, Phillips, & Watenpaugh, 1998).

In general, most of the landscape erosion that occurs in the world is due to water and the flow thereof (The Authors of Encyclopaedia Britannica).

Hydraulic action

IV. Solution or corrosion (Waugh, 1995).

Erosion occurs in three (3) basic directions:

I. Head-ward erosion

II. Vertical erosion/downcutting

III. Lateral erosion

Head-ward Erosion

This occurs at the source of the stream (this would be first order streams according to Strahler’s method of stream ordering) where weathered materials like rocks are brought by overland flow and down the slope (slopes are steep in first order streams). This causes the source stream to erode backward or further inward thereby lengthening the river.

Vertical Erosion/Downcutting

This refers to the riverbed (the bottom of the river) being eroded and occurs on the river bed of the upper course of the stream. It results in the river becoming deeper.

Lateral Erosion

As the name suggests (i.e. lateral) this type of erosion occurs at the sides or banks of the river thereby widening the river. This mostly occurs at the banks of the middle and lower courses.

As the water passes through the channel, the water obviously wields pressure on the river bank resulting in undercuts which widens cracks, if they are present.

Some factors which affect erosion are the nature of the load (greater load weight results in increased erosion), amount of load, discharge and velocity (larger the load, high velocity and discharge all result in an increased