Causes and Types of Floods

Volcanic eruptions and earthquakes can directly lead to flooding. The lava flows and large debris ejected from the eruption can block stream and creek beds causing the water to build up and flow in a new direction.

In low areas, severe flooding is caused by atmospheric conditions, and it leads to heavy rain or the rapid melting of snow and ice. Human activities that degrade the environment often increases flooding.

One of the biggest causes of floods is excessive and heavy rainfall. Most flash flooding is caused by slow-moving thunderstorms, thunderstorms repeatedly moving over the same area, or heavy rains from hurricanes and tropical storms.

Risk of flooding can be reduced by the building of dams, detention basins, educational and awareness programs related to floods, and building regulations for new developments. In existing developed areas, risk can be reduced by modifying flood behavior, property modification measures, and response modification measures.

Flooding includes large amounts of precipitation, the melting of snow and ice, tsunamis caused by typhoons and earthquakes, and structural causes in the region. In the case of the United States, the river overflows as it melts in heavy snow every year, causing serious flood damage.

There are Flash floods, Coastal floods, River floods, Urban floods, and Pluvial floods.

As a representative flood, coastal flooding is a phenomenon in which seawater rises to the ground due to a large amount of rain and typhoons in the summer. Coastal flooding is caused by the influence of seawater rushing to the ground due to typhoons and earthquakes.

Massive rainfall, overflowing of the rivers, collapsed dams, snowmelt, deforestation, climate change, emission of greenhouse gases contribute to flooding. If greenhouse gases continue to be emitted at the current level, heavy rains that are strong enough to cause flooding will increase by 29% in about 10 years, 46% in 30 years, and 53% on average at the end of the century 70 years later.