October 31, 2016 - 16:08 AMT
ARTICLE
Destructive power of moving water
How to stay safe in floods
A natural disaster is any catastrophic event that is caused by nature or the natural processes of the earth. The severity of a disaster is measured in lives lost, economic loss, and the ability of the population to rebuild. Events that occur in unpopulated areas are not considered disasters. So a flood on an uninhabited island would not count as a disaster, but when a populated area is flooded…

There are few places on Earth where people need not be concerned about flooding. Any place where rain falls is vulnerable, although rain is not the only impetus for flood.

A flood occurs when water overflows or inundates land that's normally dry. This can happen in a multitude of ways. Most common is when rivers or streams overflow their banks. Excessive rain, a ruptured dam or levee, rapid ice melting in the mountains, or even an unfortunately placed beaver dam can overwhelm a river and send it spreading over the adjacent land, called a floodplain. Coastal flooding occurs when a large storm or tsunami causes the sea to surge inland.

1911 Yangtze River Flood, China

Moving water has awesome destructive power. When a river overflows its banks or the sea drives inland, structures poorly equipped to withstand the water's strength are no match. Bridges, houses, trees, and cars can be picked up and carried off. The erosive force of moving water can drag dirt from under a building's foundation, causing it to crack and tumble, The National Geographic says.

When floodwaters recede, affected areas are often blanketed in silt and mud. The water and landscape can be contaminated with hazardous materials, such as sharp debris, pesticides, fuel, and untreated sewage. Potentially dangerous mold blooms can quickly overwhelm water-soaked structures. Residents of flooded areas can be left without power and clean drinking water, leading to outbreaks of deadly waterborne diseases like typhoid, hepatitis A, and cholera.

How to stay safe

If you live in a flood-prone area, you should prepare you house to reduce the likelihood of damage.

-Put weather protection sealant around basement windows and the base of ground-level doors.

-Install the drainage for downspouts a sufficient distance from your residence to ensure that water moves away from the building.

-Consider installing a sump pump and zero reverse flow valves in basement floor drains.

-Do not store your important documents in the basement. Keep them at a higher level, protected from flood damage.

2013 Alberta Floods, Canada

Most floods take hours or even days to develop, giving residents ample time to prepare or evacuate. Others generate quickly and with little warning. These flash floods can be extremely dangerous, instantly turning a babbling brook into a thundering wall of water and sweeping everything in its path downstream.

If you are caught in a flood

-Avoid walking or driving through flood waters. Just about 15cm of moving water can knock you down, and over 60cm of water can sweep your vehicle away.

-If there is a chance of flash flooding, move immediately to higher ground.

-If floodwaters rise around your car but the water is not moving, abandon the car and move to higher ground. Do not leave the car and enter moving water.

-Avoid camping or parking along streams, rivers, and creeks during heavy rainfall. These areas can flood quickly and with little warning.

2014 Kashmir Valley Flood, India

Most flood destruction is attributable to humans' desire to live near picturesque coastlines and in river valleys. Aggravating the problem is a tendency for developers to backfill and build on wetlands that would otherwise act as natural flood buffers. Many governments mandate that residents of flood-prone areas purchase flood insurance and build flood-resistant structures.

The deadliest flood in history

The 1931 China floods or the Central China Floods are considered the most devastating among all other disasters in the world. It included a series of floods back to back resulting in a death toll of around 4 million people. Several animals and cattle were killed as well. Extreme conditions in other seasons were a warning for this heavy storm and flood. This flood affected around 25 million people on a whole in some way or the other. The Yangtze and Huai rivers, both major rivers of China flooded at once leading to this catastrophe. It started in August 1931 when the Yangtze River’s height raised after continuous three day rain. On August 19, 1931, Huai River’s water height exceeded the maximum limit and drowned around 200,000 who were in their sleep. Millions died due to water borne diseases (Cholera, Typhoid), cases of infanticide and cannibalism were reported.

Lusine Mkrtumova / PanARMENIAN.Net