What is a flood?
It is a natural event where a piece of land that is usually dry land, suddenly gets submerged under water. Some floods can occur suddenly and recede quickly. Others take days or even months to build and discharge.
When floods happen in an area that people live, the water carries along objects like houses, bridges, cars, furniture and even people. It can wipe away farms, trees and many more heavy items.
Floods occur at irregular intervals and vary in size, duration and the affected area. It is important to note that water naturally flows from high areas to low lying areas. This means low-lying areas may flood quickly before it begins to get to higher ground. In this lesson, we shall see more about what causes flooding, the types of flooding, some effects of floods and what we can do before, during and after floods occur.
Which areas are more likely to flood?
From the causes of floods and the types that we just read about, you can tell that floods are more likely to occur in some areas than others.
Generally, the natural behavior of water is that it moves from higher ground to lower ground. This means, the lower ground is a lot more likely to experience floods.
Additionally, anywhere that rains fall, floods can develop. This is so because anytime there are more rains bringing more water than it can be drained or absorbed by the soil, there is a flood potential.
In many cities, there are buildings springing up in many places where they have not been authorized. Some of these building are placed in waterways. Other places also have very bad and chocked drainage systems. The danger is that, with the rains, water will find its own level if it cannot find its way. The result is flooding and your home could be under water. Any plain low-lying area adjacent a river, lagoon or lake is also more likely to have floods anytime the water level rises. This includes coastal areas and shorelines, as seawater can easily be swept inland by strong winds, tides and tsunamis.
WHAT ARE THE EFFECTS OF FLOODING?
Floods can have devastating consequences. Their main effects are:
- Economic During floods, roads, bridges, farms, houses and automobiles are destroyed. People become homeless. All these come at a heavy cost to people and the government. It usually takes years to be re-build all the damaged roads, bridges and buildings.
- Environment The environment also suffers when floods happen. Chemicals and other hazardous substances end up in the water and eventually contaminate the water bodies that floods end up in. In 2011, a huge tsunami hit Japan, and sea water flooded a part of the coastline. The flooding caused massive leakage in nuclear plants and has since caused high radiation in that area. Authorities in Japan fear that Fukushima radiation levels are 18 times higher than even thought.
- People and animals Many people and animals have died in flash floods. Many more are injured and others made homeless. Water supply and electricity are disrupted and people struggle and suffer as a result. In addition to this, flooding brings a lot of diseases and infections including military fever, pneumonic plague and dysentery.
…But… There is also something good about floods, especially those that occur in flood plains and farm fields. Floodwaters carry lots of nutrients that are deposited in the plains. Farmers love such soils, as they are perfect for cultivating some kinds of crops.
POWERPOINT PRESENTATION ON FLOODS:
WORKSHEETS ON FLOODS:
VIDEOS TO REVIEW: