River Hazards & Opportunities (Cambridge International IGCSE Geography)

Specification checklist

This content page covers the following section of the specification:

• 1.3.1 - The opportunities and hazards of living near a river.

Opportunities and hazards of living near a river

Spec point — The opportunities and hazards of living near a river.

• The main river hazards are flooding and erosion

• Rivers flood when the water in them reaches bankfull discharge and then overspills across the floodplain

• Flooding occurs as a result of two main causes:

  • If there is a period of heavy, torrential rain, leading to high levels of overland flow because the water cannot infiltrate
  • A prolonged period of steady rain means that the ground becomes saturated, leading to high levels of overland flow because the water cannot infiltrate

• There are other natural causes of river flooding, which include

  • landslides
  • snow and ice melt
  • storm surges push water up the river channel

• Although the root cause of flooding is precipitation, the risk of flooding can be increased by human activities such as

  • urbanisation
  • deforestation
  • building of bridges and dams
  • human-induced climate change
  • agriculture

• Flooding often goes hand in hand with erosion of the banks, as both result from increased discharge and velocity

Hazards of flooding and erosion

• Floodwaters may increase the spread of water-related diseases;

  • The water may act as a breeding ground for the animals that spread disease, for example, the mosquito
  • The water may be contaminated by bacteria, which can spread diseases such as cholera

• Deaths and injuries as floodplains are often densely populated due to the fertile soils

• Bridges and transport routes may be damaged or destroyed by the floodwaters

• Destruction of crops

• Increased insurance costs

• Lower house prices

• Rebuilding costs

River bank erosion

• Erosion of the riverbanks is another hazard

• This may be exacerbated (made worse) by flooding

• River bank erosion leads to the loss of:

  • Farmland
  • Housing
  • Transport routes

• This leads to displacement of populations

• It is estimated that 2400km of riverbanks in Bangladesh are vulnerable to erosion

• In 2019, the homes of 8,000 people in the north of Bangladesh were destroyed due to riverbank erosion

Opportunities

• As well as the hazards, there are many opportunities provided by rivers:

  • The silt deposited during flooding is often rich in minerals and nutrients

    • This makes it ideal for growing crops

  • Rivers are a source of food

  • The floodplains are flat land

    • Construction and building of transport networks easier

  • Water can be used to irrigate farmland

  • Leisure and tourism

  • Generating electricity

  • Transporting goods and people

Exam Hint When answering a question about the opportunities and hazards of living near a river, always make sure to address both sides of the argument clearly. Use specific examples (e.g., "floods in Bangladesh cause destruction, but also deposit nutrient-rich silt that helps farming").