Zusammenfassung der Ressource
Coastlines 4
- ***BANGLADESH***
- The country
- South Asia. Neighbours India. Capital is Dhaka. 25%
of country is only 1 metre above sea level. Most of the
land forms a delta by Canges, Brahmaputra and
Meghna (rivers). Deposition takes place in these rivers
therefore the land is subsiding.
- Physical causes of flooding
- Huge flood plain and delta. Snowmelt from Himalayas in
late spring and summer. Bangladesh experiences heavy
monsoon rains, especially in highlands. Tropical storms
bring heavy rains and coastal flooding. The main cause
was the above average & long period of heavy rain which
caused all 3 rivers to have their peak flow at the same
time.
- Human causes of flooding
- Deforestation in Nepal and the Himalayas increases run off and
adds to deposition and flooding downstream. Urbanisation of the
flood plain has increased magnitude and frequency of floods.
Global warming is blamed for sea level rise, increased snow melt
and increased rainfall in the region (monsoons and cyclones).
Poorly maintained embankments (levees) leak and collapse in
times of high discharge.
- The effects on the people
- 1998 FLOOD: Over 50% of the land area was
flooded. Over 1,000 killed. 7 million homes
destroyed. 25 million people homeless.
- SUSTAINABLE MANAGEMENT OF THE COASTLINE
- Shoreline Management Plan (SMP)
- Do nothing and allow the gradual erosion
- Hold the line. Use hard engineering such as timber
or rock groynes and concrete sea walls to protect
the coastline, or add extra sand to a beach to make
it more effective at absorbing wave energy.
- Retreat the line. Punch a hole in an existing
coastal defence to allow land to flood naturally
between low and high tide (the intertidal zone)
- Advance the line. Build new
coastal defences further out to sea
- ***ESSEX***
(South East of
England. North
East of London.
Coastal)
- Management Realignment
- Advantages: Sea defences are too expensive.
The land is poor-quality farmland. Do not have to
keep maintaining, therefore you save money.
Conservationists (environment people) believe it
was a good idea as it wasn't protected land, and
this action could bring new wildlife to the local
area.
- Disadvantages: Some farmers do not want their
land to be flooded. Peoples homes could be
effected. Sea level rise won't make a difference by
a few cm's. Instead of flooding the land, we could
use the land to build more houses. UK is
experiencing a housing crisis and the most
popular place is the Thames Gateway in the
South East of England.
- How does it work?
- Retreating the line. Holes being punched
through the embankments. Invading sea
water moves slowly across the land at high
tide and deposits mud. The deposits of mud
absorbs wave energy and acts like a natural
buffer against erosion. Prevent flooding of
homes and businesses in Thames estuary.