Flashcards in Rivers On Maps And River Discharge Deck (13)
What are contour lines?
Orange lines on maps that tell you the height of land in metres
How can you tell the steepness of a river on a map?
By how close the lines are
What is river discharge?
The volume of water that flows in a river per second
Measured in cubic metres per second
Measured on a hydrograph
What is peak discharge?
The biggest discharge within a period of time
What is lag time?
The delay between peak rainfall and peak discharge
What is the rising limb?
The increase in river discharge as rainwater flows into the river
What is the falling limb?
The decrease in river discharge as the river return to normal level
How does amount and type of rainfall affect surface run off?
Lots of rain / short heavy periods of rainfall = more surface runoff
Lag time decreased so discharge increases
How does temperature affect river discharge?
Hot dry conditions and cold freezing conditions both result in hard ground which increases run off
Lag time decreased so discharge increased
How does previous weather conditions affect river discharge?
After lots of rain, soil can become Saturdays more water won't be able to infiltrate
Lag time is decreased and discharge in increased
How does rock type affect river discharge?
Water infiltrates through pore spaces in permeable rock, little run off so lag time increased discharge decreases
Water can't infiltrate into impermeable rock which means lots of run off, decreased lag time increased discharge
How does land use affect river discharge?
Urban areas are covered with impermeable materials so increased run off lag time decreased discharge increases