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Drought ( Disaster Management)
- 1.
- 2. Drought is a deficiencyin precipitation over an extended period, usually a season or more, resulting in water shortage causing adverse impacts on vegetation animals and people.
- 3. Types Of Drought: There are three conditions that are generally referred to as drought : Hydrological Drought Agricultural Drought Meteorological Drought
- 4. Hydrological Drought Hydrological drought refers to deficiencies insurface and subsurface water supplies. It is measured as streamflow and as lake,reservoir and ground water levels.
- 5. Meteorological Drought This type ofdrought is all about the weather and when there is a prolonged period of below average precipitation, which creates a natural shortage of available water.
- 6. Agricultural Drought Agricultural Drought occurs when there is enoughwater for a crop to grow at a particular time.
- 7. CAUSES OF DROUGHT NaturalCauses : Weather - increased amount of anticyclone weather means air holds less moisture and we get less air. Global Warming - weather pattern changes . Hotter weather - more evaporation than precipitation . El Nino - random weather event that reverses normal weather pattern. Human Causes : Overpopulation - too many people living in an area using too much water. Over cultivation - planting large number of crops that use too much water. Over extraction - removing too much of water from wells so they dry up. Deforestation - cutting down trees which otherwise store water + hold soil together.
- 8. Effects Of Drought ● Hungerand Famine ● Thirst ● Disease ● Wildfires ● Social Conflicts and War ● Migration and Relocation
- 9. Preventive Measures ● Growmore trees. ● Develop irrigation facilities by building dams. ● Indulge in rain water harvesting. ● Spray water on the base of the plants so that less water is used. ● Grow drought resistant crops like millets,maize and sorghum. ● Build a canal to divert the water. ● Put more wells and tube wells.
- 10. Case Study-1 The Sahel (Anatomyof a drought) 1960s - 1980s
- 11. Causes: ● Natural ClimaticCauses (low Precipitation) ● Deforestation ● Desertification ● Overgrazing ● Overcultivation DEFORESTATION : When trees are cut down soil is more easily washed away. OVERGRAZING: Traditional Nomadic tribes settled in one place.Vegetation no longer protected the soil. OVERCULTIVATION: Cultivating the same land again and again ruins soil quality destroying nutrients meaning nothing grows on it.
- 12. DESERTIFICATION : Desertification occurswhen land turns into dessert. Impacts Of Desertification : ● People cannot find enough food for their cattle - FAMINE. ● Crops and Cattle Die. ● People are forced to leave their own country and take refuge in other countires - then they are known as refugees. ● Increase in Sand Storms. ● Flash Floods. Thank You