Category :
9th Class
Specific Hazards and Mitigation
IMPORTANT TERMS AND CONCEPTS
- Sudden onset hazards: Earthquakes, tsunamis, volcanic eruptions, landslides, floods, cloud burst, tropical cyclones, avalanches.
- Slow onset hazards: Famine, drought, pest infestation, environmental degradation, desertification.
- Industrial/technological disasters: Fire, explosion, chemical leakage/spillage, system failures.
- Multi-hazard zones: Some areas are exposed to many hazards like coastal areas may experience floods, cyclones, earthquakes etc.
- Tremor: Shaking of the earth's surface.
- Epicenter: The place on the surface of the earth which is the center of the earthquake.
- Richter scale: A scale which measures the magnitude of an earthquake.
- Modified Mercalli Scale: A scale which measures the intensity of an earthquake.
- Seismic zone: An area prone to earthquakes.
- Seismologists: Scientists who study all aspects of earthquake.
- Tsunami: A seismic sea wave or destructive tidal wave generated by underwater earthquake.
- Cyclone: It is a storm and develops when a low pressure area in the atmosphere is surrounded by high pressure. Cyclones are associated with strong winds, heavy rains, tidal waves etc.
- Hurricane: Storms with violent winds in the Atlantic ocean.
- DWS: Disaster Warning System.
- Typhoons: Storms like cyclones in the Pacific Ocean.
- Willie Willie: Storms like cyclones in Australia.
- Storm Surge: Seawaves water is pushed towards the shore by the force of winds swirling around cyclone.
- Arid region: Areas which receive scanty rainfall, dry areas with very little vegetation.
- Droughts: Acuter shortage of water, food, fodder due to scanty rainfall and scarcity of water.
- Water stress: When the demand for water exceeds the available amount or when poor quality restricts its use.
- Aquifer: Water bearing formation that stores or transmits water, such as wells, tube-wells and springs. These water bearing formations are capable of providing water in sufficient quantity.
- Drip-irrigation: A common irrigation method where pipes/tubes filled with water slowly drip into crops. Less water is lost to evaporation and is useful in dry areas.
- Groundwater: Water obtained from the depth of the earth, of more than 15 m. It is obtained through tube-wells. It is recharged by rainfall.
- Rainwater harvesting: It is a technique of recharging and increasing of underground water by storing rain water and allowing it to percolate in the earth’s surface.
