eq1 - physical factors affecting drainage basin Flashcards
what is the drainage basin
an open system that is an area of land that is drained by a river and its tributaries
what are the 3 types of inputs affecting the hydrological cycle
- convectional- ground warms causing evaportation which casues intense weather
- orographic- warm moist air forced to rise overupland areas causing rainfall
- frontal- moist air meets colder polar ari forming rain
what are the physical factors affceting the drainage basin
- interception
- infiltration
- percolstion
- direct runoff
- saturated overland flow
- infiltration excess overland flow
- growndwater flow
what is intercerption
raindrops are prevented from from falling directly onto the ground surface due to the layer of vegetation
vegetation prevents the rate of precipitation
what is infiltration
where water is absorbed
what is percolstion
similar to inflitration however involves deeper transfer of water into permeble rock
what is direct runoff
water flowing over the surface of the ground
what is saturated overland flow
occurs when water accumulates in the soil and cannot absorb any more water. This causes water to run off the surface.
what is infiltration excess overland flow
occurs when rainfall intensity exceeds
the infiltration capacity so excess water flows over the ground surface
what are the 3 physical factors affceting the driange basin outputs
- evaporation
- transpiration
- channel flow
4.
what is channel flow
water that has been collected to flow in a river or stream
what
what is evapotranspiration
The total amount water removes from the drainage basin by the process of transpiration and evaporation
name the 5 factors whihc determine the importance of the flows outputs and inputs
- climate
- soils
- veg
- geology
- relief
vegations contibution
transpiration increases deu to more vegeation
vegetaion with a low albedo wiill reflect will absorb more solar rad meaing increased evaporation
climates contribution
– influences
amount of rainfall and
vegetation growth.
soils contribution
nfluences rate of infiltration
and throughflow.
geologys contibution
affects
percolation and
groundwater flow
relief conribution
➢ Relief – steeper gradients
of land will encourage faster
rates of surface runoff
name the 4 human disruptions of the drainage basin
cloud seeding
urbanisation
dam construction
groundwater abstraction
what is cloud seeding
this is the attempt to change the amount or type of preciptation by dispersing substances into the air.
what is urbanisationan and what does it create
urbanisation creates impermeable surfaces that reduce infiltration adn increase surface runoff