Flooding Flashcards
What is a flood?
An overflow of water onto land that is usually dry.
What are some conditions that can lead to flooding?
Prolonged or heavy rainfall, river channels reaching bankfull capacity, overflowing lakes and reservoirs, and snowmelt.
How do humans sometimes worsen the impact of floods?
By interfering with the natural flow of rivers and building on floodplains.
What is a floodplain?
Low-lying land on either side of a river, subject to flooding.
What is the benefit of regular flooding on a floodplain?
It can deposit fertile silt, enriching farmland.
What is a prolonged rainfall flood?
A slow-onset flood caused by extended periods of heavy rain, often due to a series of depressions.
What is a flash flood?
A fast-onset flood caused by an intense storm with high levels of rainfall and potential storm surges.
How do monsoons contribute to flooding?
Monsoons are seasonal wind changes that can bring heavy rainfall, particularly intense monsoons (often linked to La Niña) can cause significant flooding.
What is a glacial outburst flood (jökulhlaup)?
A sudden release of meltwater from a glacier or ice cap.
How does geology influence flooding?
Impermeable rock leads to faster runoff and increased flood risk. Soil depth affects water storage capacity and saturation levels.
What are the meteorological factors that cause flooding?
Prolonged rainfall (slow-onset), intense storms (fast-onset), extreme monsoonal rainfall, and snowmelt.
What are physical factors that cause flooding?
Shape of the land, land elevation, geology, and drainage density.
How do human activities increase flood risk?
By building on floodplains, urbanizing areas (impermeable surfaces), deforestation, and mismanaging rivers (hard engineering).
What are some health risks associated with flooding?
Drowning, waterborne diseases (e.g., cholera), and mental health issues.
How can floods impact property?
Structural damage to buildings, contamination with sewage and pollutants, and loss of possessions. It can also lead to difficulties in obtaining insurance in flood-prone areas.
How does building on floodplains increase flood risk?
It reduces the floodplain’s natural water storage capacity and increases runoff due to impermeable surfaces.
How does deforestation contribute to flooding?
It reduces interception and evapotranspiration, leading to more water reaching the ground and rivers quickly. It also increases soil erosion, reducing channel capacity.
What is hard engineering in river management and how can it worsen flooding?
Straightening and deepening rivers can reduce local flood risk but increase flow speed and volume downstream, potentially worsening flooding in other areas.
What are some negative environmental impacts of flooding?
Contamination of groundwater, eutrophication of water bodies, soil erosion, and contamination of soil.
What are some benefits of flooding for the environment?
Replenishment of lakes, wetlands, and groundwater; fertilization of farmland with deposited silt; increased biodiversity.
What is the role of the polar jet stream in UK flooding?
It influences the track and intensity of storms. A southerly jet stream can bring more warm, moist air to the UK, leading to heavy rainfall.
What were some impacts of the 2024 Storm Bert floods on November 22nd?
100mm+ rainfall in South Wales
6,500 people were left without power in Northern Ireland at its peak.
Roads submerged in Yorkshire, extensive flooding by snowmelt.
At least 5 deaths.
How can floods affect agriculture?
Damage to crops due to waterlogging and disease, reduced yields, and contamination of farmland.
What caused Storm Bert (2024)?
A slow-moving low-pressure system over the Atlantic brought persistent rain and strong winds to the UK.
