7 Causes of Flooding Explained
Causes of flooding are; ocean waves, deforestation, climate change, glacier melting, heavy rainfall, infrastructural failure, and unsustainable resource consumption. This article discussed the causes of flooding, as follows;
1). Ocean Waves (as one of the Causes of Flooding)
Ocean waves are a common cause of flooding in coastal areas [2].
In such areas, large amounts of wind energy and wave power cause the mobilization of water from the sea, thereby forming waves that migrate toward the coast.
As these waves break on the coast, water is deposited.
The severity of flooding caused by waves, depends on factors like the volume of water involved, the relative altitude or level of the coast (compared to the sea level), and the permeability of soil on the coast.
Flooding by ocean waves is more likely to occur in areas characterized by high sea level. In such areas, it is not uncommon for the level of nearby lands to be lower than that of the sea.
Areas with less-permeable or low-moisture-absorption-capacity soil, are also susceptible.
The absence of natural barriers like dunes, or manmade defensive structures along the coast, can worsen the environmental impact of waves as a cause of flooding.
2). Deforestation
Natural forests, vegetated lands, grasslands, and all ecosystems with significant presence of plants, are less susceptible to flooding than their exposed counterparts.
This is due to the natural tendency of vegetation to facilitate soil conservation, biodiversity enhancement, and water conservation [4].
When such vegetation (especially trees) is lost due to deforestation, the land becomes more prone to flooding.
There are multiple ways in which this effect can be explained. One of them is fact that plant roots improve soil structural resilience and fertility by holding sediments firmly together and allowing biomass to accumulate.
The loss of these plants leads to a decline in fertility, moisture retention, infiltration, and structural resilience of the soil.
Alternatively, it may be said that deforestation causes flooding by facilitating climate change. Since plants act as natural carbon sinks and air pollutant-interceptors, their removal will allow more greenhouse gas emissions, which will induce global warming, weather variability, and irregular/excessive rainfall patterns, all of which can cause flooding.
Aside flooding, deforestation can lead to other environmental problems like erosion and desertification.
3). Climate Change (as one of the Causes of Flooding)
Climate change is a major cause of large-scale flooding [5].
This is because of the effects of climate change on the environment, which include increase in temperature, heat waves, and extreme, irregular weather patterns.
These effects cause the sea level to rise, through the melting of glaciers, leading to the degradation of temperate ecosystems like the tundra.
Climate change also makes the soil more vulnerable to flooding by causing drought and fertility loss.
4). Glacier Melting
Although it is one of the effects of climate change, glacier melting must be discussed separately as a cause of flooding, due to its significant role in flooding events within temperate areas.
The runoff from melting glaciers can produce large streams of water which reach their peak volume in the summer.
These streams may be useful in cases where other sources of water are depleted. However, they cause significant damage within and beyond their environs.
Effects of glacier-induced flooding can be particularly severe when the melting involves frozen lakes and rivers.
5). Heavy Rainfall (as one of the Causes of Flooding)
Rainfall is arguably the most common and effective cause of flooding.
The role of rainfall in flooding is particularly significant in cases of extreme, rapid precipitation; as such conditions make it difficult for soil to absorb water effectively or early. Delays or inefficiency in moisture absorption will lead to flooding.
Heavy rainfall can play a role in various types of flooding, including coastal, fluvial, pluvial and flash flooding. It is however most commonly associated with flash flooding, whereby large amounts of stormwater accumulate rapidly within an area [1].
In addition to causing infrastructural damage and socioeconomic loss, heavy rainfall-induced flooding is linked to other forms of environmental degradation like stormwater pollution.
6). Infrastructural Failure
Infrastructural failure is both a cause and an effect of flooding.
As a cause of flooding, infrastructural failure involving water conservation/management facilities can induce flooding.
Such facilities include water dams, rainwater harvesting systems, and greywater recycling systems.
Dams are used to manage fluvial flooding by restricting the flow of excessive water in rivers during the high-tide or rainy season. Their damage or collapse can cause such water to be released rapidly into the environment, and can be very hazardous [3].
Wastewater facilities can overflow or collapse as well, causing temporary flooding and pollution.
Drainages and other containment structures may also induce flooding when they damaged, their capacity exceeded, or when they are constructed such that they obstruct the natural flow path(s) for stormwater.
7). Unsustainable Resource Consumption (as one of the Causes of Flooding)
Unsustainable methods of agriculture and mining can cause flooding, by altering soil, regional drainage, and topography.
These practices can also cause resource depletion and reduce the capacity of the environment to sustain natural processes of hydrological cycling.
Replacing such practices with sustainable farming and circular economic practices, can mitigate the risk of flooding.
Conclusion
Causes of flooding are;
1. Ocean Waves
2. Deforestation
3. Climate Change
4. Glacier Melting
5. Heavy Rainfall
6. Infrastructural Failure
7. Unsustainable Resource Consumption
References
1). Dinis, P.; Huvi, J.; Pinto, M. S.; Carvalho, J. (2021). “Disastrous Flash Floods Triggered by Moderate to Minor Rainfall Events. Recent Cases in Coastal Benguela (Angola).” Hydrology 8(2):73. Available at: https://doi.org/10.3390/hydrology8020073. (Accessed 24 October 2022).
2). Hsu, T.; Shih, D.; Li, C.; Lan, Y.; Lin, Y. (2017). “A Study on Coastal Flooding and Risk Assessment under Climate Change in the Mid-Western Coast of Taiwan.” Water 9(6):390. Available at: https://doi.org/10.3390/w9060390. (Accessed 24 October 2022).
3). Kostecki, S.; Banasiak, R. (2021). “The Catastrophe of the Niedów Dam—The Causes of the Dam’s Breach, Its Development, and Consequences.” Water 13(22):3254. Available at: https://doi.org/10.3390/w13223254. (Accessed 24 October 2022).
4). Simões, M. P.; Belo, A. D.; Pinto-Cruz, C.; Pinheiro, A. (2014). “Natural vegetation management to conserve biodiversity and soil water in olive orchards.” SPANISH JOURNAL OF AGRICULTURAL RESEARCH 12(3):633-643. Available at: https://doi.org/10.5424/sjar/2014123-5255. (Accessed 24 October 2022).
5). Toosi, A. S.; Doulabian, S.; Tousi, E. G.; Calbimonte, G.; Alaghmand, S. (2020). “Large-scale flood hazard assessment under climate change: A case study.” Ecological Engineering 147(3). Available at: https://doi.org/10.1016/j.ecoleng.2020.105765. (Accessed 24 October 2022).
