local factors

• How does the height of the land increase flood risk?

  low-lying land is more vulnerable to rising sea levels and storm surges

  storm surges and spring tides leads to water flooding areas of the back shore and beyond

  Maldives as a case study -

  Bangladesh has land that isn't more than 1m above sea level
• How does the height of the land make an area more vulnerable?

  low elevation areas, such as estuaries and deltas, are more susceptible to coastal flooding

  storm waves and a higher sea level can more easily flood these features

  low-lying islands such as the Maldives are also at risk of submergence
• How does subsidence make an area more vulnerable to coastal flooding?

  building settlements, along with the weight of the buildings increases the risk of subsidence thus the land becomes lower and more vulnerable to coastal flooding

  clearing land for agriculture- preventing the natural deposition of sediment that used to maintain the islands' height

  as well as ground water extraction increases the risk of subsidence
• How does removing vegetation increase an areas risk of coastal flooding?

  mangroves stabilise coastlines against erosion

  provide protection and shelter against extreme weather events such as floods and tsunamis

  they absorb and disperse tidal surges associated with these events
• Removal of vegetation example?

  recent satellite studies show that 71% of Bangladesh's mangrove is now retreating by 200 metres a year

  the causes of this are human actions that deliberately remove vegetation

  globally half of all mangrove forests have been lost since the mid-twentieth century converting the forest into lucrative shrimp farms accounts for 25% of this loss, happening in Asia (including Bangladesh)
• Sri Lanka, protecting mangroves?

  after the devastating 2004 Indian ocean tsunami it showed that 2 people died in the settlement protected by dense mangrove and scrub forest, while up to 6000 people died in the village that had removed the vegetation

  partly as a result of this, Sri Lanka has become the first nation in the world to protect all of its mangrove forests

  its scheme protects 8800 hectares of remaining forest, as well as replanting mangroves that have already been felled
• How do storm surges increase the risk of flooding in coastal areas?


  • Storm surge events can lead to severe coastal flooding with dramatic short-term impacts
  • Storm surges are caused by:
  • Depressions (low pressure) leading to storm events
  • Tropical cyclones 
  • Warmer ocean temperatures combined with higher sea levels are predicted to make storms and tropical cyclones more frequent and more sever
• Storm surges?

  • A storm surge is a rise in the sea level as a result of a storm or tropical cyclone and affect approximately 1.5 million people a year with a range of short-term impacts including:
  • Deaths and injuries
  • Homes destroyed leading to homelessness
  • Increase in water borne diseases
  • Destruction of infrastructure
  • Businesses destroyed leading to loss of employment and decrease in GDP
  • Loss of power
  • Loss of agricultural land
  • Destruction of crops and livestock