The Drainage Basin Processes
Drainage basin
- A major part of the hydrological system, drainage basins drain all the water which lands on the Earth's surface
- A drainage basin is an open system
- Every drainage basin is unique and is different in shape and size, with different rock types, relief and land use
Drainage basin features
- All drainage basins have some features in common:
- Watershed
- Source
- Confluence
- Tributary
- Mouth
Drainage Basin Features
Channel network
- Every drainage basin is covered by a network of tributaries which connect to the main river channel. The numbers of tributaries in a drainage basin is referred to as the drainage density:
- Drainage basins with lots of tributaries have a high drainage density
- Drainage basins with few tributaries have a low drainage density
Worked example
Study Fig 1, which shows information about flows through the drainage basin,
(i) What is meant by transpiration?
[1]
-
Answer:
- The changing of water to water vapour by plants/evaporation of water by plants/trees/vegetation [1]
(ii) Identify the processes which take place at X ,Y and Z in Fig 1.
[3]
- Answer:
- X = Overland flow/surface run off [1]
- Y = Through flow [1]
- Z = Ground(water) flow [1]
