drainage basins

Created by

charlotte mcclure

Cards (45)

What is the main input in the drainage cycle?
Precipitation
How can precipitation vary in the drainage cycle?
It can vary in form, amount, intensity, seasonality, and distribution.
What effect does snow have on the drainage system?
It delays the entry of water into the drainage system.
How does the amount of precipitation affect the drainage basin?
It affects the amount of water in the drainage basin and the fluxes within it.
What is the relationship between precipitation intensity and flooding?
The greater the intensity, the greater the likelihood of flooding.
How does seasonality affect the drainage basin system?
It results in the drainage basin system operating at different flow levels at different times of the year.
Why is distribution significant in large drainage basins?
Because tributaries start in different climate zones.
What are the seven different flows important in transferring precipitation into the drainage network?
Interception
Infiltration
Percolation
Throughflow
Groundwater flow
Surface runoff
River or channel flow
What is interception in the context of drainage flows?
It is the retention of water by plants and soils which is subsequently evaporated or absorbed by vegetation.
How does infiltration differ from percolation?
Infiltration is the process by which water soaks into the soil, while percolation is a deeper transfer of water into permeable rocks.
What is throughflow in the drainage cycle?
It is the lateral transfer of water downslope through the soil.
What is groundwater flow?
It is the very slow transfer of percolated water through pervious or porous rocks.
What is surface runoff?
It is the movement of water that is unconfined by a channel across the surface of the ground.
When does river or channel flow occur?
It occurs as soon as the water enters a river or stream, confined within a channel.
What is evaporation in the context of drainage outputs?
It is the process by which moisture is lost directly into the atmosphere from water surfaces, soil, and rock.
What is transpiration?
It is the biological process by which water is lost from plants through minute pores and transferred to the atmosphere.
What is discharge in the context of drainage outputs?
It is the flow of water into another, larger drainage basin, a lake, or the sea.
What is a drainage basin?
It is the area of land drained by a river and its tributaries, also known as a river catchment.
How is the boundary of a drainage basin defined?
It is defined by the watershed.
How does a drainage basin fit into the global hydrological cycle?
It is a subsystem within the global hydrological cycle and is an open system with external inputs and outputs.
How do drainage basins vary in size?
They can vary from small local streams to large rivers like the Amazon.
What is the relationship between tributary streams and larger rivers?
The drainage basins of tributary streams and small rivers nestle within the drainage basins of larger rivers.
How does climate impact the drainage basin system?
It influences the type and amount of precipitation and the amount of evaporation.
What role does climate play in vegetation type?
Climate impacts the type of vegetation that can grow in a drainage basin.
How do soils affect the drainage system?
Soils determine the amount of infiltration and throughflow, and indirectly, the type of vegetation.
What is the most important flow affected by soils?
Surface runoff is perhaps the most important flow affected by soils.
How does geology affect the drainage system?
Geology impacts subsurface processes such as percolation and groundwater flow, and indirectly affects soil formation.
What is the relationship between geology and groundwater flow?
Geology can impact groundwater flow through pervious or porous rocks.
How does relief affect the drainage system?
Relief can impact the amount of precipitation and the amount of runoff.
What is the most important flow affected by relief?
Surface runoff is perhaps the most important flow affected by relief.
How does vegetation affect the drainage system?
Vegetation impacts the amount of interception, infiltration, overland flow, and transpiration rates.
What human changes disrupt the drainage basin system?
Changes to rivers, drainage, and the character of the ground surface disrupt the drainage basin system.
How do storage reservoirs affect river flows?
They hold back river flows.
What is the effect of water abstraction for domestic and industrial use?
It reduces river flows.
How does groundwater abstraction for irrigation affect water tables?
It lowers water tables.
What is the effect of deforestation on evapotranspiration?
It reduces evapotranspiration but increases infiltration and surface runoff.
How does changing land use from arable to pastoral affect overland flow?
It increases overland flow due to soil compaction by livestock.
What is the effect of changing land use from pastoral to arable?
It increases infiltration by loosening and aerating the soil.
How does urbanization affect surface runoff?
Urban surfaces speed surface runoff by reducing percolation and infiltration.
What is the impact of drains on rainfall delivery to streams and rivers?
Drains deliver rainfall more quickly to streams and rivers, increasing chances of flooding.