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Flashcards in Water budgets and river systems Deck (19)
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1

Define 'water budget'

The annual balance between inputs and outputs
Positive = surplus
Negative = deficit

2

How is precipitation calculated?

P = Q + E +or- S
Discharge + EVT +/- Storage

3

What is a storm hydrograph?

Shows variations in a river's discharge over a short period of time during a storm event to record how a river responds to precipitation

4

How can urbanisation affect a river's carrying capacity?

Tend to be channelized so if the capacity is breached flooding will increase downstream

5

How does a greater population density impact a river regime?

- More infrastructure
- Contribute to pollution
- Bridges can act as pin points to dam water when they get blocked

6

How do drains and sewers impact a river regime?

- Decrease lag time
- Increase velocity

7

How can the impacts of urbanisation be managed?

- Consider appropriate land use
- Limit urbanisation
- Flood management strategies
- Use permeable surfaces where possible
- Flood proof property design

8

Define 'flood'

When the capacity of a river to transport water is exceeded and water flows over its banks

9

Define 'base flow'

Average day-to-day discharge of the river

10

Define 'bankfull discharge'

The volume of discharge that a particular river channel is capable of carrying without flooding

11

Define 'rising limb'

The part of a storm hydrograph in which discharge increases

12

Name the two types of hydrograph

Flashy and flat

13

Describe the weather of a flashy and flat hydrograph

Fy - Antecendent rainfall so soil is saturate
Ft - Dry soil allowing infiltration if it is not compacted

14

Describe the geology of a flashy and flat hydrograph

Fy - Igneous rocks (impermeable) e.g. granite
Ft - Permeable e.g. sandstone

15

Describe the soil of a flashy and flat hydrograph

Fy - Clay based to not allow infiltration/ compacted e.g. farm machinery
Ft - Sandy soils

16

Describe the relief of a flashy and flat hydrograph

Fy - High and steep with little lag time
Ft - Elongated basins with more time to infiltrate

17

Describe the basin size and shape of a flashy and flat hydrograph

Fy - small and circular
Ft - long and large to increase lag time

18

Describe the vegetation of a flashy and flat hydrograph

Fy - Less
Ft - Dense

19

Describe the land use of a flashy and flat hydrograph

Fy - Urban
Ft - Rural