river discharge

Question 1

def

Answer 1

volume of water flowing per second

Question 2

what graph shows discharge

Answer 2

hydrograph shows how the discharge at a certain point in a river changes over time in relation to rainfall

Question 3

peak discharge

Answer 3

highest discharge in the period of time being looked at

Question 4

lag time

Answer 4

delay between peak discharge and peak rainfall

Question 5

rising limb

Answer 5

the increase in river discharge as rainwater flows into a river

Question 6

falling limb

Answer 6

the decrease in river discharge as the river returns to its normal level

Question 7

reason for lag time

Answer 7

most rainwater doesn’t land directly in the river channel. surface run off or infiltration

Question 8

physical factors affecting flood risk

Answer 8

heavy rainfall - arrives too quickly to infiltrate so lots of surface run off increasing discharge
geology - impermeable rocks so runoff is increased
relief - if a river is in a steep sided valley water will reach the river channel quicker cuz it can flow faster, increasing discharge

Question 9

human factors affecting flood risk

Answer 9

land use - buildings are often made by impermeable materials like concrete which and surrounded by roads made by impermeable surfaces increasing surface run off. man made drains then transport run off to rivers increasing discharge

trees intercept water on their leaves which then evaporates , trees also take up and store water from the ground, so cutting down trees increases the volume of water entering the river channel

Question 10

shorter lag time means

Answer 10

peak discharge is higher so flooding is more likely to occur