flooding

• An ageing population

  Increases flood risks
• Impacts of an ageing population on flood risks


  • High rate of disease from water contamination
  • Inability to reach health providers
  • Secondary health impacts: heart disease, hypothermia
  • Less prepared for flooding
  • Less likely to respond to flood warnings
  • Find it more difficult to flood proof their homes
  • Electricity shortages may damage things like life support
  • Find it harder to recover
  • Deal with the loss of memorabilia and stress from the flood more intensely
  • Harder to deal with insurance claims
  • Older people living with mental health problems find it more difficult to respond to flood warnings
• Physical causes of flooding

  • Amount and type of rainfall
  • Relief
  • Temperature
  • Previous weather conditions
  • Snowmelt
  • Rock type
• Physical causes of flooding

  • The North-West of the UK experiences heavy rain. The combination of warm, wet, westerly winds and upland areas produces orographic rainfall (E.g Cumbrain Fells)
  • Long steady rainfall will produce rivers which rise slowly but can flood
  • Heavy short showers can cause the river to rise quickly and burst from it's banks
  • Monsoon rains occur across South and South-East Asia from May to September. In July 2016 these rains caused flooding, landslides and evacuations in the Philippines
  • Longer than normal, low-pressure systems can bring heavier rain than usual
• Human actions that increase flood risk

  • Urbanisation
  • Climate change
  • River management
  • Deforestation
  • Change of land use
• Climate change


  Climate change refers to long-term shifts in temperatures and weather patterns. Such shifts can be natural, due to changes in the sun's activity or large volcanic eruptions.
• Urbanisation


  Urbanisation refers to the process by which an increasing proportion of a country's population comes to live in urban areas, such as cities and towns. It involves the growth and expansion of urban areas as more people move from rural to urban settings.
• River management

  The planning, control, and manipulation of rivers and their surrounding environments to achieve specific goals
• Deforestation


  The clearing or removal of trees and other vegetation from forested land
• Change in land use


  The alteration of the purpose or function of a piece of land, typically involving a shift from one land use category to another
• In many ecosystems floods play an important role in maintaining biodiversity and ecosystem functioning
• Floods can recharge groundwater systems, fill wetlands, increase connectivity between aquatic habits and move sediment and nutrients around the landscape
• Some ecosystems are resilient to flooding so they can trigger breeding, migration and dispersal
• Intense flooding can lead to eutrophication and the destruction of aquatic plants
• Eutrophication


  The gradual increase in the concentration of phosphorus, nitrogen, and other plant nutrients in an ageing aquatic ecosystem such as a lake
• Flood returns


  Aka flood recurrence interval - Estimate if the likelihood of a flood of a curtain size reoccurring
• Flood Frequency


  The size of the largest flood event of each year for a location is placed in rank order, with Rank 1 being the largest. Formula: T = n+1/M (T = recurrence interval, N = number of years of observation, M = rank order)
• The calculated recurrence level indicates the number of years within which a flood of this size might be expected
• Limitations of flood frequency analysis: based on historic data which means similar floods may occur more/less frequently. Climate change would lead us to think events will be more frequent
• The floods of highest magnitude will have much longer return periods – While they have the highest impact they may be less likely to occur
• Key points about floods in Pakistan


  • Monsoon Rains
  • Flash Floods
  • Glacial Lake Outburst Floods (GLOFs)
  • Vulnerability
  • Historical Floods
  • Impact on Agriculture
  • Humanitarian Response
  • Mitigation Measures
  • Climate Change
• Hard engineering strategies for river management

  • Channelling
  • Dams
  • Flood relief channels
  • embankments
  • river strightning
• Channelling is an effective way of improving river discharge and reduce flood risk, but it displaces the river downstream so some other location may be overwhelmed by the increasing discharge
• Dams block sediment, the land behind the dam becomes flooded, and they also increase river bed erosion
• What are the disadvantages of dams?

  Block sediment, increase rivere bed erosion and flood the area behind the dam
• Cumbria's landscape

  • Numerous rivers and lakes including Lake Windermere
  • Susceptible to flooding, especially during heavy rainfall
• Cumbria has experienced severe flooding events

  2005
• Cumbria has experienced severe flooding events

  2009
• Cumbria has experienced severe flooding events

  2015
• 2005 Cumbria Floods


  January 2005 saw significant flooding in Cumbria due to heavy rainfall, prompting discussions on flood management
• 2009 Cumbria Floods


  November 2009 witnessed widespread flooding in Cumbria, particularly affecting towns like Cockermouth and Keswick, resulting in fatalities and substantial property damage
• 2015 Storm Desmond


  Storm Desmond in December 2015 led to devastating flooding, causing extensive damage to infrastructure, homes, and communities, with widespread power outages and travel disruptions
• Efforts have been made to improve flood defences and management, including building flood barriers, enhancing river channels, and raising public awareness
• Cumbria faces increased flood risks due to climate change


  More intense rainfall events and rising sea levels likely exacerbating flooding in the future
• Local communities in Cumbria have worked to enhance resilience through flood action groups, emergency plans, and awareness programs