A man shared photos of the current state of his house and his surrounding after a 9-hour rainfall yesterday in Yenagoa, Bayelsa state, Nigeria. According to reports, many people have been rendered homeless after the ugly scenario
All you need to know about flood and how to prevent it
Flooding
A flood occurs when a river bursts its banks and the water spills onto the floodplain . Flooding tends to be caused by heavy rain: the faster the rainwater reaches the river channel , the more likely it is to flood. The nature of the landscape around a river will influence how quickly rainwater reaches the channel.
The following factors may encourage flooding:
A steep-sided channel - a river channel surrounded by steep slopes causes fast
surface run-off .
Lack of vegetation or woodland - trees and plants intercept precipitation (ie they catch or drink water). If there is little vegetation in the drainage basin then surface run-off will be high.
A drainage basin consisting of mainly
impermeable rock - this will mean that water cannot percolate through the rock layer, and so will run faster over the surface.
Dumping refuse into drainage systems -
The act of dumping wastes into drainage systems lead to blockage of the drainage which subsequently prevents easy water flow. Solid wastes hold water and causes overflow of drainage channels.
How do you prevent Flood?
There are actually many preventative steps that can be taken to ensure that we remain safe.
1. Green roofs/rooftop gardens
Green roofs (roofs that are covered with vegetation), by their very nature, absorb rainwater and help to mitigate flooding. They have become very popular across Europe. The benefits, as they relate to water, are straightforward: for the building owner, it’s a stormwater management tool; for the community, it reduces stormwater runoff; and for the environment, it prevents combined sewer overflow, neutralizes the acid rain effect and removes nitrogen pollution from the rainwater.
2.Create flood plains and overflow areas for rivers
There was a time when floodplains covered large stretches along European rivers. Today, because of urban sprawl, less than half remain. There is a movement to restore these floodplains because of their significant role in flood protection, water management and nature conservation. Essentially, what floodplains do is retain and absorb water, thereby shielding nearby towns from the effects of heavy rainfall.
3. Separating rainwater from the sewage system
To improve water management and protect the sewage system from damage, cities are beginning to revamp their underground pipe and drainage systems – by separating rainwater
from the sewage system. The separation enables the wastewater treatment plant to function properly, without it being overburdened by large quantities of stormwater.
4.Plant Trees
Deforestation allows for easy flooding. Planting of trees help prevent flood by holding up a considerable amount of water.
5.Keep the sewer system clean, so it can do its job
It seems like an obvious measure, but sewer systems can clog up with waste, debris, sediment, tree roots and leaves. The more traditional sewer pipes have a tendancy to rust and corrode, compounding the problem.
6. Sustainable drainage: permeable pavement, sidewalks and gardens
In some urban areas, green space is considered a luxury. On the ground and on rooftops, there is so much concrete. Concrete is not permeable. It does not absorb rainwater. It blocks it and redirects it to the drainage systems which, in turn, often become clogged and then the water overflows into the streets and sidewalks. Unchecked, this will cause flooding. The concept of sustainable drainage makes perfect sense.
As part of environmental initiatives that are underway in Europe and across the globe, the recommendation is that impermeable surfaces be replaced with permeable materials such as grass and gardens. This will allow the rainwater to drain into the soil. The process, known as infiltration, also serves to sustain the plant life.
Credit: waving.com Please share this information with others