Flooding is an environmental hazard involving the submergence of land by large volumes of water. This article discusses flooding meaning and types, as outlined below;
Flooding Meaning: 4 Ways to Define Flooding
Flooding is the submergence of land areas by large volumes of water.
The above is a simple, basic perspective on flooding. Below is an alternative flooding meaning, which portrays it from the perspective of its role as an environmental impact or hazard;
Flooding is a water-related environmental problem which could be either a manmade or natural hazard, and which involves the introduction of significant amount of water into a given area, so that normally-dry land becomes submerged under water .
As an environmental hazard, flooding is related to other hazardous conditions and events like; stormwater pollution, soil erosion, and landslides . The following flooding meaning highlights some causes of flooding;
Flooding is the accumulation of large volumes of water in an area as a result of heavy rainfall, glacier melting, sea level rise, ocean waves, failure of artificial drainage facilities and water dams . Some causes listed above are also linked to climate change and global warming. These include glacier melting, heavy rainfall and sea level rise.
Flooding is a hazardous process whereby large volumes of water fill and submerge a given area, leading to infrastructural damage, erosion, loss of life and property, agricultural land loss, waterborne disease spread, spread of oil spill and other contaminants, and decline of biodiversity and bioenergy in the ecosystem.
Types of Flooding
Types of flooding are; coastal, river, inland, urban, flash, groundwater, mild, and severe flooding.
They are classified based on environmental conditions, geographic location, mechanism of fluid flow, and degree of severity.
1). Coastal Flooding (as one of the Types of Flooding)
This type of flooding occurs in areas along the coast.
It is also called ‘tidal’ flooding, and is usually caused by ocean currents, and can lead to significant erosion, especially in low-elevation zones .
2). River Flooding
Also known as ‘fluvial’ flooding, river flooding occurs in areas within and close to the river bank.
It is directly caused by overflowing of the river basin, and can be induced by heavy rainfall.
The severity of such events depends on the size of the river, amount of water involved, and the nature of the surrounding area. Some river floods have lead to huge socioeconomic and environmental losses.
3). Inland Flooding (as one of the Types of Flooding)
Inland flooding is the general term used to describe all flood incidents that occur away from coasts and river banks.
The most common cause is excessive rainfall, although other factors like overflow of drainages, can contribute to the occurrence.
4). Urban Flooding
As the name implies, urban flooding is the accumulation of large volumes of water and the submergence of land in urban (and suburban) areas. Many factors can contribute to this type of flooding.
Urban areas are particularly susceptible to flooding due to the obstruction of natural water drainages by manmade structures and waste materials . The permeability of the ground and hence its ability to absorb water, is also limited in urban areas due to the presence of concrete and asphalt pavements.
Although there are structures for flood control in urban areas, the sudden failure or limited capacity of these facilities still pose a risk.
Due to the concentration of both human and material resources in such areas, urban flooding can be very hazardous.
5). Flash Flooding (as one of the Types of Flooding)
Flash flooding involves the relatively-rapid rise of stormwater in a given area after a short period of intense rainfall or water release .
It may occur within the context of any other type of flooding, and could be the result of any of various causes.
Flash floods are powerful and cause significant damage and displacement.
6). Groundwater Flooding
Groundwater flooding is caused by a significant rise in the water table, so that groundwater overflows the aquifer and rises above the surface.
The main cause of such events is irregular and high rates of rainfall. Groundwater flooding simply indicates an inability of underground formations to absorb and contain water.
Aside rainfall, it could also be linked to the characteristics of underground formations, such as permeability and porosity.
Groundwater flooding is not usually as severe as other types, and is often temporary.
7). Mild Flooding (as one of the Types of Flooding)
Mild flooding is any cause of water inundation which is associated with less damage than most cases.
It usually affects only low-level areas, and is common in regions close to water bodies.
Mild flooding may also cause some damage, and often requires evacuation to minimize its impacts.
8). Severe Flooding
As the name implies, this type of flooding is relatively severe and is associated with significant consequences.
Flash and urban flooding are both types of flooding that can be severe.
9). Pluvial Flooding (as one of the Types of Flooding)
Pluvial or ‘surface-water’ flooding involves the formation of large pools of water in inland regions, with little or no influence from any major water body like a river or sea.
The two main causes of pluvial flooding are high-intensity rainfall and low ground-permeability. It is common within urban areas, and could result from the overflowing of artificial drainage systems .
Flooding is an environmental hazard involving the introduction of large amounts of water into a given area, and the resultant submergence of land.
Types of flooding are;
1. Coastal Flooding
2. River Flooding
3. Inland Flooding
4. Urban Flooding
5. Flash Flooding
6. Groundwater Flooding
7. Mild Flooding
8. Severe Flooding
9. Pluvial Flooding
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