Define
Flood
A flood means that dry areas of land are covered with a lot of water. Many parts of India get flooded during the rainy season.
What is a natural disaster?
A disaster is an unexpected event that kills a lot of people and causes a lot of damage. A natural disasters are events in nature that is big, spread over a large area and causes loss of life and property
How are cyclones formed?
Cyclones happen when the air over the sea becomes warm very quickly and rises upwards. Cooler air rushes in to take its place. This fast-moving air swirls around in a circle and creates a cyclone.
Drought
A drought happens when there is little or no rain for a long time. Crops cannot grow and there is a shortage of water.
How are people made aware about the possibility of a natural disasters?
When disasters are likely to happen, the government warns the people and also makes arrangements to rescue disaster-hit people. This has helped in saving lives, but often the damage to property and crops cannot be prevented.
What role can weather scientists play in order to alert people about cyclones?
Weather scientists can predict a cyclone forming over the sea. So, people can be warned about staying indoors, or in the case of a severe cyclone to move to another place. Even fishermen are warned to not go out to sea. Medical kits, emergency medicines, first aid kits, food and water, torches and portable radio with batteries can be kept ready.
Cyclone
A cyclone is an extremely strong storm in which strong winds move in a circle. This is accompanied by heavy rain that sometimes leads to flooding.
What causes the flooding of an area?
An area can get flooded due to the following reasons: a) continuous heavy rains b) overflowing of river water c) poor drainage system.
How do landslides occur?
Landslides usually occur when there is
• heavy rain in the mountains. This loosens the rocks and soil and makes them move.
• Landslides become more frequent when there is heavy deforestation, thus exposing the land since there are no trees to hold the soil together with their roots.
• Eg. Himalayan region.
Tsunami
A severe earthquake under the sea that causes an extremely large and high wave in the sea is called a tsunami.
What are the damages caused by floods?
Floods cause damage to life and property. Huts and houses get washed away. Farmers suffer major losses as their crops get destroyed. Floods can also cause shortage of food and contaminate water. Thus, causing water borne diseases like cholera, diarrhoea, etc.
What is the epicentre of an earthquake?
The place on the surface of the earth where an earthquake is the strongest is called the epicentre.
Volcanic Eruptions
A volcano is a mountain with a large opening at the top, right through which gases and hot molten rock are forced out into the air. When these are thrown out with great force, it is called a volcanic eruption. Eg - Active volcano – Mt. Etna in Italy
Dormant or sleeping volcano – Mt. Ararat in Turkey
Extinct volcano – Mt. Kenya in Africa
Explain the importance of rainwater harvesting in case of a drought
Rainwater harvesting is useful, in case of a drought. The rainwater that falls on the ground is collected for use and does not go waste. This way the water can be used later as well.