Powerpoint on Drought (Geography) USacademy.in

Powerpoint on Drought (Geography) USacademy.in

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  Jawahar Navodaya Vidyalaya Topic-Disaster Management Balod, (C.G.) Geography project Made by Guided by Aayush Uike Mr. S.K. Singh (Pgt.Geography) This Photo by Unknown author is licensed under CC BY-NC. (Drought)
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  Contents • What isDisaster management ? • Mitigation, Preparedness & Response • Types of Drought • Meteorological drought • Agricultural drought • Hydrological drought • Causes of drought • Protection mitigation and relief
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  What is Disaster management? Disaster Management can be defined as the organization and management of resources and responsibilities for dealing with all humanitarian aspects of emergencies, in particular preparedness, response and recovery in order to lessen the impact of disasters.
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  Mitigation, Preparedness &Response Drought mitigation, preparedness and response comprise the appropriate measures and actions aimed at reducing the vulnerability to drought and reducing the impacts of droughts. The goal of the pillar on drought mitigation, preparedness and response is to determine appropriate mitigation and response actions aimed at risk reduction, the identification of appropriate triggers to phase in and phase out mitigation actions, particularly short-term actions, during drought onset and termination and, finally, to identify agencies or ministries or organizations to develop and implement mitigation actions.
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  Types of Drought Droughtis mainly defined in three ways:- i) Meteorological drought ii) Agricultural drought iii) Hydrological drought
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  Meteorological drought Meteorological droughtoccurs when there is a prolonged time with less than average precipitation. Meteorological drought usually precedes the other kinds of drought.
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  Agricultural Drought Agricultural droughtsaffect crop production or the ecology of the range. This condition can also arise independently from any change in precipitation levels when either increased irrigation or soil conditions and erosion triggered by poorly planned agricultural endeavors cause a shortfall in water available to the crops. However, in a traditional drought, it is caused by an extended period of below average precipitation
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  Hydrological drought Hydrological droughtis brought about when the water reserves available in sources such as aquifers, lakes and reservoirs fall below a locally significant threshold. Hydrological drought tends to show up more slowly because it involves stored water that is used but not replenished. Like an agricultural drought, this can be triggered by more than just a loss of rainfall
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  Causes of drought Precipitationdeficiency Mechanisms of producing precipitation include convective, stratiform, and orographic rai nfall. Convective processes involve strong vertical motions that can cause the overturning of the atmosphere in that location within an hour and cause heavy precipitation, while stratiform processes involve weaker upward motions and less intense precipitation over a longer duration.]Precipitation can be divided into three categories, based on whether it falls as liquid water, liquid water that freezes on contact with the surface, or ice. Droughts occur mainly in areas where normal levels of rainfall are, in themselves, low. If these factors do not support precipitation volumes sufficiently to reach the surface over a sufficient time, the result is a drought. Temperature increases Evaporation increases Ground dries
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  Dry season Within thetropics, distinct, wet and dry seasons emerge due to the movement of the Intertropical Convergence Zone or Monsoon trough. The dry season greatly increases drought occurrence, and is characterized by its low humidity, with watering holes and rivers drying up. Because of the lack of these watering holes, many grazing animals are forced to migrate due to the lack of water in search of more fertile lands. This Photo by Unknown author is licensed under CC BY-NC-ND.
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  Erosion and human activities Humanactivity can directly trigger exacerbating factors such as over farming, excessive irrigation deforestation, and erosion adversely impact the ability of the land to capture and hold water. In arid climates, the main source of erosion is wind. Erosion can be the result of material movement by the wind. The wind can cause small particles to be lifted and therefore moved to another region (deflation). Suspended particles within the wind may impact on solid objects causing erosion by abrasion (ecological succession). Wind erosion generally occurs in areas with little or no vegetation, often in areas where there is insufficient rainfall to support vegetation.
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  Climatic changes Overall, globalwarming will result in increased world rainfall. Activities resulting in global climate change are expected to trigger droughts with a substantial impact on agriculture throughout the world, and especially in developing nations. Along with drought in some areas, flooding and erosion could increase in others. Some proposed solutions to global warming that focus on more active techniques, solar radiation management through the use of a space sunshade for one, may also carry with them increased chances of drought.[
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  Consequences of drought Onecan divide the effects of droughts and water shortages into three groups: environmental, economic and social. • In the case of environmental effects: lower surface and subterranean water-levels, lower flow-levels (with a decrease below the minimum leading to direct danger for amphibian life), increased pollution of surface water, the drying out of wetlands, more and larger fires, higher deflation intensity, loss of biodiversity, worse health of trees and the appearance of pests and dendroid diseases. • Economic losses include lower agricultural, forests, game and fishing output, higher food-production costs, lower energy-production levels in hydro plants, losses caused by depleted water tourism and transport revenue, problems with water supply for the energy sector and for technological processes in metallurgy, mining, the chemical, paper, wood, foodstuff industries etc., disruption of water supplies for municipal economies.
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  Protection, mitigation andrelief • Dams – many dams and their associated reservoirs supply additional water in times of drought. • Cloud seeding – a form of intentional weather modification to induce rainfall. This remains a hotly debated topic, as the United States National Research Council released a report in 2004 stating that to date, there is still no convincing scientific proof of the efficacy of intentional weather modification.[ • Rainwater harvesting – Collection and storage of rainwater from roofs or other suitable catchments. • Recycled water – Former wastewater (sewage) that has been treated and purified for reuse. • Transvasement – Building canals or redirecting rivers as massive attempts at irrigation in drought-prone areas.
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  Thank You