We are heavily affected by natural disasters and climate change. Among them, storms and floods frequently occur, causing loss of life and significantly affecting the economy. Terrifying cataclysms include: the 2020 flood that left severe consequences for the Central region and Vietnam with painful losses of life and property; and the Kerala floods in 2018, The southern Indian state of Kerala suffered terrible floods when torrential rain flooded the entire area, hundreds of people killed and 22,000 people were left homeless after the floods.

So what is a flood? What is its root cause? What do we need to do to minimize this situation? We will answer all of them through this article.

1. What is a flood?

• Flood is a phenomenon of inundation, where fast-flowing water has the ability to wash away houses and trees. Normally, floods have high flow rates, are sudden and appear mainly in high mountainous areas with steep hilly terrain.
• Flood is a phenomenon in which an area of land is flooded for a certain period of time.

Thus, simply understanding a flood is a phenomenon in which the water level flowing in rivers and lakes exceeds the prescribed level, leading to inundation, dyke overflow, and dyke breakage.

2. Cause of floods

Objective reasons

• Storm or storm surge

Storms and high tides can cause heavy rains, creating huge amounts of flood water and inundating coastal areas.

• Heavy rain continues for a long time

Prolonged heavy rain in the delta areas leaves water basins on dikes or rivers with no place to drain.

• Tsunami and tidal disasters

Tidal or tsunami phenomena are also a cause of flooding in the central coastal provinces of Vietnam. Due to the water level overflowing, rising, overflowing the goats or hydroelectric reservoirs, causing flooding

Subjective reasons

• Deforestation

Indiscriminate deforestation and unplanned resource exploitation cause hills and mountains to erode, easily causing landslides and flooding when the rainy season comes. In addition, cutting down trees in large numbers affects the process of photosynthesis. Therefore, increased carbon-dioxide levels in the atmosphere cause changes in climate, causing threats of natural disasters such as floods.

• Dispose of trash into the environment

Indiscriminate dumping of garbage into the environment causes blockages in drains and ditches, seriously affecting water supply and drainage during floods.

• Concreted

Strong and rapid concreting reduces the ground area, causing poor water permeability and increased flooding.

• Greenhouse gas

The burning of fossil fuels, industrial influences, and pollution, are all depleting the levels of the ozone layer and increasing the levels of greenhouse gases, becoming the main cause of man-made floods.

3. What do we need to do to minimize floods?

Construction measures

• Construction of lakes does not regulate floods in areas where floods often occur. In areas where flash floods often occur, research should be combined with the planning of water exploitation and treatment, and the construction of water reservoirs with many functions such as flood prevention, water storage for agricultural production, electricity generation, Combined with flood regulation and flood prevention. Open flood drainage routes. Organize the opening of flood-gathering roads upstream and areas that need protection to prevent flow blockages and water accumulation causing floods;
• Solidly build a system of dykes and flood walls;
• Expanding the flood drainage aperture of the traffic bridge and culvert system;
• Regularly dredge streams, estuaries, and canals so that when there is a flood, the water will recede quickly.

Environmental measures

• Do not throw trash indiscriminately into the environment, affecting the flow during floods;
• Plant and protect watershed protection forests to protect the ecological environment, protect plant cover, increase the water retention capacity of the basin, and limit the ability to concentrate flood flows;
• Use and exploit natural resources and fuel with planning.

DOCUMENTATION

1. https://kenhthoitiet.vn/tin-tuc/lu-lut-la-gi.html
2. https://kttvbackan.gov.vn/lu-lut-sat-lo-dat/lu-lut-la-gi-nguyen-nhan-gay-ra-lu-lut