# Rivers- River Discharge and Hydrographs

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What is River Discharge?
The volume of water flowing in a river per second, measured in cumecs.
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What factors affect river discharge?
1). Precipitation- hightens discharge the more there is 2). Hot weather- the higher the temperature, the lower the discharge because the rate of evaporation is higher. 3). Removal of water from the river (abstraction)- also reduces discharge
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What are hydrographs?
graphs showing the river discharge over a period of time
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What do hydrographs show?
how the volume of water flowing at a certain point in the river changes over a period of time. Storm hydrographs show river discharge around the time of a storm event.
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What is the Peak Discharge?
the highest point on the graph, when the river discharge is at its greatest
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What is Lag Time?
the delay between peak rainfall and peak discharge. This delay happens because it takes time for the rainwater to flow into the river. A shorter lag time can increase peak discharge because more water reaches the river during a shorter period of time
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What is the Rising Limb?
the part of the graph up to peak discharge. The river discharge increases as rainwater flows into the river.
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What is the Falling Limb?
the part of the graph after peak discharge. Discharge is decreasing because less water is flowing into the river. A shallow falling limb shows water is flowing in from stores long after its stopped raining.
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What is a 'flashy' hydrograph?
when the graph has steep, roughly symmetrical rising and falling limbs.
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## Other cards in this set

### Card 2

#### Front

What factors affect river discharge?

#### Back

1). Precipitation- hightens discharge the more there is 2). Hot weather- the higher the temperature, the lower the discharge because the rate of evaporation is higher. 3). Removal of water from the river (abstraction)- also reduces discharge

### Card 3

#### Front

What are hydrographs?

### Card 4

#### Front

What do hydrographs show?

### Card 5

#### Front

What is the Peak Discharge?