What is a flood?
Of all natural hazards capable of producing a disaster, a flood is the most common in causing loss of life, human suffering inconvenience, widespread damage to buildings, structures, crop, infrastructure, and other national assets.
Severe weather conditions which lead to intense rainfall such as tropical depressions and hurricanes often lead to flooding.
Types of floods
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 through 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 Floods: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, for example, flooding in New Market.
Causes of floods
The following are the main causes of flooding in Jamaica:
- Low-lying coastal areas
- Areas near gully banks
- Flood plains or major rivers
- Lower sections of closed limestone valleys
- Areas vulnerable to landslides
- Low-lying coastal towns and villages
Source: ODPEM