Geography rivers

Geography rivers

Geography Rivers

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• Caption: https://www.slideshare.net/noelhogan/the-geography-of-rivers

Hard engineering 1

• Dams and reservoirs- Reservoirs (artifical lakes) are formed behind a dam
• Pros-Reservoirs can store water and can provide a good water source plus it reduced the many risk of a flood
• Cons-They are exspensive to build it can alter the course of the river also it can erode material that is trapped behind the dam
• Straightening-Rivers that are artificially straightened
• Pros-as the water is transported away it can reduce the risk of a flood
• Cons-The water goes down stream quicker so the water is transported out of the area quicker.

How factors affect a flood risk

• Geology
• Rocks such as granite and clay does not allow precipitation to infiltrate increasing surface runoff
• Relief
• slopes will cause surface run off and more water will get into the river increasing the likely hood of a flood.
• Land use
• Buildings and roads can increase the likelihood of a flood

Hard engineering 2

• Embankments-walls raised along a river bank
• Pros-the channel can hold more water plus flooding will less frequent
• Cons-Can be expensive and the flood water can be trapped on the flood plain.
• Flood relief channels-Water that is diverted away from protected areas
• Pros-Water being controlled by flood gates
• Cons-Can be expensive and as a result of the water moving quicker erosion is more likely to happen.

Soft engineering 1

• Flood warning and preparations-a alert to the public either by apps, tv or even radio
• Pros-Can give people time to grab their things and evacuate and it can reduce the impact of flooding
• Cons-The flood will still come and same people might not get the alert
• Flood plain zoning-Parts of the flood plain have been restricted to reduce the impact of a flood
• Pros-impacts of flooding is reduced so the flood plain can retain natural functions
• Cons-it can restrict the development and economical growth of an area and can not offer help on already built land

Soft engineering 2

• Planting trees-Trees can intercept rain water
• Pros-Very cheep option, soil erosion is reduced and can increase wild life
• Cons-