Indian Natural Disasters 10th Notes KSEEB Social Science
→ Disasters may be natural or manmade.
→ Geological hazards are natural disasters such as earthquakes, volcanoes, tsunamis, landslides and avalanches.
→ Weather associated disasters are cyclones, drought, floods and epidemics
→ Natural disasters of infrequent and unpredictable
→ In a cyclone the winds blow spirally inwards towards the centre of low pressure.
→ Tropical cyclones are common in India.
→ Tropical cyclones are very destructive and cause huge loss to life and property
→ The eastern coast of India is prove to cyclones
→ Some preventive measures against cyclones are :
- Paying heed to cyclone warning
- Taking protection in the cyclone shelters
- Developing mangrove forests along the coastline to check impact of cyclone and soil erosion.
→ Flood refers to the inundation of land by river water
→ Floods may be caused by natural and man made factories.
→ Natural factors of floods are heavy rainfall, melting of snow, tropical cyclones, cloud burst, silting of river beds.
→ Man made causes of floods are deforestation, faulty irrigation and agriculture practices, breaching of barrages and rapid urbanization.
→ The ill-effects of floods are
- Floods causes loss of life and property.
- Damage to crops, vegetation etc.
- Breakdown of communication and power system.
- Dislocation of transport system.
- Soil erosion, disruption of essential services etc.
→ The measures to control floods are :
- Afforestation of catchment areas of rivers
- Construction of dams across rivers
- Construction of river embankments near low lying areas
- Flood forecasting and early warning
→ The sliding of land mass along steep slopes of hills or mountains is called land glides.
→ The constant process of sea waves along sea coasts leads to erosion of coasts
→ Coastal erosion is also caused by
- Monsoon winds
- Tropical winds and
- Tsunamis.
→ Some preventive measures of coastal erosion are :
- Constructing sea walls, groins, break waters to protect the coastal areas from wave erosion
- Restricting sand mining in coastal regions
- Planting trees along beaches and coastal dunes.
→ An earthquake is a violent vibration in the earth’s crust.
→ Earthquake occur due to Tectonic plate movements, volcanic eruption, faulting and folding in the earth’s crust, collapse of underground roof caves, hydrostatic presence of man made water reservoirs.
→ The three main earthquake zones in India are :
- The Himalayan Zone
- The Indo-Gangetic Zone
- The Peninsular Zone
→ INAUNDATION: Flooding
→ CLOUD BURST: Sudden violent rain storm
→ TSUNAMI: Huge tidal waves caused by under sea earthquake.
→ GROYNES: A series of groynes, including huge rock masses or concrete logs, these are placed at right angles to the store lines to reduce the coastal erosion.
→ BREAKERS: A barrier built into sea to check the impact of waves to protect the coast.