- Created by: LivWisden
- Created on: 18-04-17 09:21
Water on the Land
The Hydrological Cycle
The hydrological cycle is also known as the water cycle.
Seas and oceans contain 97 per cent of the world's water, and ice holds 2 per cent. That leaves just 1 per cent of the world's water as fresh water on land or in the air. This water is recycled again and again through the process of evaporation, condensation and water transfers such as surface run-off.
Percolation is the movement of water through lots of tiny particles.
A drainage basin is the area drained by a river/ the area from which a river channel receives water and its tributaries.
Some drainage basin key terms are:
Source- The start point of a stream or river, such as a spring.
Mouth- Where a river meets a body of water, such as sea.
Tributaries- A small stream or river flowing into the main river.
Watershed- The line where drainage basins met and which determines to which basin precipitation will go.
Confluence- The point in which two rivers join together, for example a tributary joining a main river.
How does a River Change Downstream?
Ox bow lake, meander
Larger, greater quantity
Limited in quantity
Gradient of Land
Width of Valley and Shape
Narrower and V-shaped
Wider and U-shaped
Pastoral faming, recreation
Commercial industry, residential
Capacity of River
Competence of River
· Capacity- Maximum load a river can transport.
· Competence- Maximum size of particle that the river can transport (however due to erosion the particles in the river are smaller downstream).
· Bedload- How much sediment is carried on the bed of the river. These particles are too big to be carried on the surface.
· Suspended load- How much sediment is carried on the surface of the river (small enough to not have to be carried on the bed).
The shape of the valley and channel changes along the river depending on whether erosion or deposition is having the most impact (is the dominant process). Geographical models to show this:
Long Profile- A long profile of a river shows you how the gradient changes over the different courses.
Cross Profile- The cross profile shows you what a cross section of the river looks like.
Valley and Channel Shape
V-shaped valley, steep sides
Narrow, shallow channel
Gently sloping valley sides
Wider, deeper channel
Very wide, almost flat valley
Very wide, deep channel
Vertical and Lateral Erosion Change the Cross Profile of a River
Erosion can be vertical or lateral – both types…