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.