Water On The Land - River Discharge

Front 1

What is river discharge?

Back 1

River discharge is the volume of water that flows in a river per second. It's measured in cumecs cubic metres per second.

Front 2

What does a hydrograph show?

Back 2

A hydrograph shows how the discharge at a certain point in a river changes over time.

Front 3

What do storm hydrographs how?

Back 3

Storm hydrographs show the changes in a river discharge around the time of a storm.

Front 4

What is peak discharge?

Back 4

The highest discharge in the peroid of the time you're looking at.

Front 5

What is lag time?

Back 5

The delay between peak rainfall and peak discharge.

Front 6

What is rising limb?

Back 6

The increase in river discharge as the rainwater flows into the river.

Front 7

What is the falling limb?

Back 7

The decrease in river discharge as the river returns to it's normal level.

Front 8

Why does lag time happen?

Back 8

Lag time happens because most rainwater doesn't land directly in the river channel -- there's a delay as rainwater gets into the channel.

Front 9

What is surface run off?

Back 9

When water flows overland.

Front 10

What is infiltration?

Back 10

Infiltration is the downwards movement of water that seeps into the soil or porous rock.

Front 11

How does more surface runoff lead to a greater discharge?

Back 11

More surface runoff means a reduced lag time. This means discharge will be greater because more water gets to the river channel in a short amount of time.

Front 12

List all the factors that affect river discharge.

Back 12

Amount of rainfall, Temperature, Previous Weather Conditions, Rock Type,Land use and relief.

Front 13

How does temperature effect river discharge?

Back 13

Temperature can effect river discharge because hot dry conditions an cold,freezing conditions both result in hard ground -- this increases run off. Lag time decreased, so discharge increases.

Front 14

What type of rock infiltrates through pore spaces?

Back 14

Permeable rock infiltrates through pore spaces.

Front 15

What rock does water flow along the cracks?

Back 15

Pervious rocks.

Front 16

How does relief affect river discharge?

Back 16

Relief effects river discharge because more runoff occurs on steep slopes. Lag time decreases, so discharge increases.

Front 17

How does urbanisation affect river discharge?

Back 17

Urbanisation can effect river discharge because urban areas have drainage systems and they're covered in impermable materials -- like concrete. This increases runoff. Lag time decreases, so discharge increases.