Flood

Floods are the most frequent type of natural disaster and occur when an overflow of water submerges land that is usually dry. Floods are often caused by heavy rainfall, rapid snowmelt or a storm surge from a tropical cyclone or tsunami in coastal areas.

Floods can cause widespread devastation, resulting in loss of life and damages to personal property and critical public health infrastructure. Between 1998-2017, floods affected more than 2 billion people worldwide. People who live in floodplains or non-resistant buildings, or lack warning systems and awareness of flooding hazard, are most vulnerable to floods.

There are 3 common types of floods:

Flash floods are caused by rapid and excessive rainfall that raises water heights quickly, and rivers, streams, channels or roads may be overtaken.

River floods are caused when consistent rain or snow melt forces a river to exceed capacity.

Coastal floods are caused by storm surges associated with tropical cyclones and tsunami.

When floodwaters recede, affected areas are often blanketed in silt and mud. This sediment can be full of nutrients, benefiting farmers and agribusinesses in the area. Famously fertile flood plains like the Mississippi River valley in the American Midwest, the Nile River valley in Egypt, and the Fertile Crescent in the Middle East have supported agriculture for thousands of years. Yearly flooding has left millions of tons of nutrient-rich soil behind.

However, floods have enormous destructive power. When a river overflows its banks or the sea moves inland, many structures are unable to withstand the force of the water. Bridges, houses, trees, and cars can be picked up and carried off. Floods erode soil, taking it from under a building's foundation, causing the building to crack and tumble. Severe flooding in Bangladesh in July 2007 led to more than a million homes being damaged or destroyed.

Floods can cause even more damage when their waters recede. The water and landscape can be contaminated with hazardous materials, such as sharp debris, pesticides, fuel, and untreated sewage. Potentially dangerous mold can quickly overwhelm water-soaked structures.

As flood water spreads, it carries disease. Flood victims can be left for weeks without clean water for drinking or hygiene. This can lead to outbreaks of deadly diseases like typhoid, malaria, hepatitis A, and cholera. This happened in 2000, as hundreds of people in Mozambique fled to refugee camps after the Limpopo River flooded their homes. They soon fell ill and died from cholera, which is spread by unsanitary conditions, and malaria, spread by mosquitoes that thrived on the swollen river banks.

In the United States, floods are responsible for an average of nearly 100 deaths every year, and cause about $7.5 billion in damage.

China's Yellow River valley has seen some of the world's worst floods in the past 100 years. The 1931 Yellow River flood is one of the most devastating natural disasters ever recorded—almost a million people drowned, and even more were left homeless.

The government and citizens must work together to formulate ways to prevent floods. Proper awareness must be spread about the steps to take when floods occur. Warning systems must be set up so people get sufficient time to save themselves. In addition, areas that are more likely to have floods must have tall buildings above the flood level.

Further, there should be an efficient system for storing excessive water due to rain. This will prevent the overflowing of water. One of the most important steps is to strengthen the drainage system. This can avoid water logging which will prevent floods.Other than that, dams must be constructed strongly. The use of cheap materials causes dams to break. The government must ensure there is a quality building of dams to prevent floods. In short, we cannot prevent natural causes like rain and the melting of glaciers. However, we can stop the manmade causes like breaking of dams, poor drainage system, installing warning systems and more. We should take inspiration from countries like Singapore that never experience floods despite having heavy rainfall for most time of the year.