River Hazards & Opportunities | Geography for GCSE/IGCSE - Year 11 PDF Download

Causes of River Hazards

• The primary hazards associated with rivers are flooding and erosion.
• River flooding happens when the water level reaches bankfull discharge and spills onto the floodplain.
• Flooding occurs due to two main factors:
  a. Intense, heavy rainfall causing high levels of overland flow due to poor infiltration.
  b. Extended periods of steady rainfall saturating the ground, resulting in high overland flow.
• Other natural causes of river flooding include:
  a. Landslides.
  b. Snow and ice melting.
  c. Storm surges pushing water upstream.
• Human activities can exacerbate flood risks, including:
  a. Urbanization.
  b. Deforestation.
  c. Construction of bridges and dams.
  d. Human-induced climate change.
  e. Agricultural practices.
• Floods often coincide with bank erosion due to increased discharge and flow velocity.

Hazards of flooding and erosion

• Floodwaters can exacerbate the proliferation of waterborne diseases.
  • The stagnant water may serve as a breeding ground for disease-carrying animals like mosquitoes.
  • Contamination by bacteria in the water can propagate diseases like cholera.
• Flood-related fatalities and injuries are common, particularly in densely populated floodplain areas where fertile soils attract settlement.
• Floodwaters can inflict damage or destruction upon bridges and transportation networks.
• River bank erosion results in the loss of agricultural land, residential areas, and transportation infrastructure.
• Crop destruction is a consequence of flooding.
• Flood events often lead to increased insurance premiums.
• Lower property values are often observed in flood-prone areas.

Opportunities

• Sediments deposited by river flooding are frequently nutrient-rich, enhancing soil fertility and making them suitable for crop cultivation.
• Rivers serve as a source of sustenance, providing food.
• Floodplains, characterized by their flat terrain, facilitate the construction of transportation infrastructure with relative ease.
• Water from rivers is utilized for irrigating farmland.
• Rivers offer opportunities for leisure activities and tourism.
• They can be harnessed for generating electricity.
• Rivers serve as natural routes for transporting both goods and people.