Rivers 01 Flashcards
hydrological cycle, rivers
What is a drainage basin?
the area of land that is drained by a river and its tributaries
What is the source?
Where the river usually starts, in an upland area
What is the watershed?
an imaginary line separating two drainage basins
What is the tributary?
Small rivers that join to the main river
What is the confluence?
the point where two rivers join
What is the mouth of the river?
Where the river ends and flows into sea and lakes
What is the hydrological cycle?
a closed system, a system where water is constantly recycled, and there are stores and tranfers.
Stores are places where water is held for a period of time. they include:
- water in the form of vapor or droplets held in the clouds
- surface stores; puddles,lakes, rivers and reservoirs
- interception: precipitation prevented from reaching the ground due to it being held by leaves and branches
- aquifers: permeable rocks (limestone & sandstone) which holds water
- ice & snow, seas and oceans
Transfers are the ways in which water is moved around the hydrological cycle. These include:
Evaporation
Transpiration
Evapo-transpiration
Condensation
Precpiration
Overland flow
Infiltration
Percolation
Throughflow
Groundwater flow
Reasons why overland flow occurs
- Precipitation exceeds infiltration
- Heavy rainfall
- Saturation of rock or soil
- Melting of snow and ice
- Water within soil could be frozen
- Deforestation
- The area might be covered with concrete
What are the characteristics of a river?
- Channel:
- Bed:
- Bank:
- Width:
- Depth:
- Discharge:
- Speed of flow:
- Wetted perimeter
- Thalweg
What is the channel?
Channel: the path that the river flows
What is the bed?
- Bed: the bottom of the river channel
What is the bank?
- Bank: the sides of the river channel
What is the width?
Width: the distance between two banks
