A flood is an abnormal progressive rise in the water level of streams or rivers which may result in overflowing. When an area which is normally dry land becomes partially or completely submerged due to rise in water level, flooding has also occurred. Floods in the Caribbean can often be caused by heavy rainfall, dam or levee failures, tsunamis, unusually high tides, storm surges or burst water mains.
Flash floods can occur within a few minutes or hours of excessive rainfall, a dam. Flash floods often have a dangerous wall of roaring water carrying rocks, mud and other debris.
Overland flooding, the most common type of flooding event typically occurs when waterways such as rivers or streams overflow their banks as a result of rainwater and cause flooding in surrounding areas. It can also occur when the capacity of underground pipes, or the capacity of streets and drains designed to carry flood water away from urban areas are exceeded.
What are the Different Types of Floods?
Flooding is the most common natural hazard and it can occur in different ways. Take a look below to find out more about the different types of flooding.
There are four types of flooding that affect Saint Vincent and the Grenadines and the wider Caribbean:
Flash Floods:
Flash floods are the result of heavy rainfall or cloudburst over a relatively small drainage area. Flash floods carry highly destructive flood waves and are most common in mountainous areas or in steep places that have streams flowing though narrow canyons.
Riverine Floods:
These occur when a large amount of rain falls in river systems with tributaries that drain large areas containing many independent river basins. They may last a few hours or many days depending on the intensity, amount and the distribution of the rainfall.
Tidal Flood:
This results when large bodies of water, like the sea or lakes, overflow onto bordering lands. They are mainly caused by high tides, the heavy rains that accompany hurricanes, waves created by high wind surges created by storms, and long waves produced by earthquakes out at sea.
Ponding:
This is a slow build up of water in depressions, sinks, areas with clay base soil, and slow percolation rate