Cyclones are weather systems that have caused 779324 deaths and a loss of US$ 1407.6 billion in the past 50 years. One of the calamities that cyclones are accompanied by is floods.
Cyclones cause storm surges, heavy rainfall, strong winds, and massive coastal erosion, increasing the likelihood of the region experiencing floods. The likelihood is determined by the intensity and duration of the cyclone and the infrastructural regulation and preventive measures taken in the region vulnerable to cyclones.
Cyclones can damage buildings, uproot trees, and disrupt power lines. They also displace people and cause a lot of deaths. Please continue reading further for more detailed information on the phenomena that cause floods.
Factors That Determine If A Cyclone Will Cause Floods
Not all cyclones will cause floods. There are specific types of cyclones that possess certain qualities that are capable of causing floods. Below are four factors that determine whether a flood would occur.
The intensity of cyclones varies greatly on the different sustaining elements that contribute towards their growth. A more intense cyclone will bring heavier rainfall and increase the chances of a flood forming. However, a milder cyclone may cause some destruction, but a flood will not be likely.
Cyclones only last 4-7 days on average; some cyclones can be shorter and cause minimal damage. However, cyclones that exceed this time limit and go on for weeks can be destructive. These cyclones are responsible for flooding and other natural calamities due to the long duration for which rain continues.
The behavior of cyclones is not the same in plains as in hilly areas. Moreover, the steepness of regions also plays a role in how cyclones travel. Hilly areas are less likely to experience flooding than low-lying areas where water accumulation is easier.
Sometimes cyclones are not intense and large in size, but the discrepancies in some regions’ infrastructure make the cyclone’s impact much worse. For example, areas with poor drainage systems or blocked sewage lines that do not allow for the free flow of water are very likely to be flooded when a cyclone occurs.
Phenomenons By A Cyclone That Cause Floods
A cyclone in itself is not capable of causing floods. It does cause widespread destruction, but it is the phenomena that accompany it which can cause floods. Below we discuss storm surges, heavy rainfall, strong winds, and coastal erosion resulting from a cyclone.
A storm surge is a rise in sea level that occurs when a cyclone approaches a coastline. It’s caused by a combination of strong winds and low pressure associated with the storm, which pushes water toward the shore and causes it to accumulate.
As the storm approaches the coast, the surge becomes more intense and can reach several feet or even meters above normal sea level.
Storm surges can be extremely dangerous and destructive. They can cause flooding, erosion, and damage to buildings and infrastructure in coastal areas. The higher the storm surge, the more severe the damage can be.
The height of the storm surge is determined by a number of factors, including the storm’s intensity, the coastline’s slope, and the depth of the water near the shore.
Storm surge is one of the most detrimental phenomena a cyclone brings. Their impact is very sudden, and the time for mitigation and preventive measures is very little. The sudden influx of water from the ocean in areas that are beyond the coast can cause flash floods and massive floods in other low-lying areas.
Heavy rainfalls characterize cyclones. For rainfall to occur, warm air needs to rise and form clouds which can bring precipitation; a cyclone provides the perfect environment.
The cyclone is a region of the low-pressure area. As this moves toward land, it creates a “Low” where air converges. This air then rises to the top and is replaced by a low, which brings more air into it, and the cycle continues. As warm air rises, it creates clouds, and the water condenses and falls as rain.
Due to the constant repetition of this cycle due to the cyclone, huge rain clouds continue to form, and heavy rain is experienced. This heavy rain, in turn, causes floods if the intensity and duration exceed the average.
The intensity of the cyclone determines the intensity of winds during a cyclone. As we already know, cyclones are low-pressure regions at the center, and air from outside flows in to compensate for the low pressure. The difference in pressure between a cyclone’s center and outer region is known as the “Pressure Gradient Force.”
Hence, the greater the pressure gradient force is, the stronger the winds will be during a cyclone.
Stronger winds cause the cyclone to spin faster and gain more strength. This can increase the intensity and duration of the cyclone, which further increases the chances of a flood occurring.
Coastal erosion is something that keeps taking place on its natural course with time. However, when cyclones take place, this process is fast-tracked, and the erosion is rapid. This is because cyclones have the ability to form massive waves, which have the strength to move the coastline.
As a result, large-scale destruction is seen in the coastal areas. Due to the waves pushing the coastal line away, the water enters the urban and populated areas. This can cause flash floods and cause a huge loss of buildings and even lives if the threat is not mitigated well.
Most regions that are susceptible to cyclones ensure that there are action plans in place. These include building sea walls, nourishing beaches, and evacuating nearby areas when a threat is detected.
Cyclones bring with them destruction that can take years to deal with. The impacts of a natural disaster like a cyclone can be seen in the country’s social, economic, and political aspects. Investments in adequate detection and planning can manage the long-term impacts of cyclones and save the country a lot in money and human lives.