Unit ii drought

Unit ii drought

• 2.
   Drought isan extended period of months or years when a region notes a deficiency in its water supply whether surface or underground water.  Generally, this occurs when a region receives consistently below average precipitation.
• 3.
   It canhave a substantial impact on the ecosystem and agriculture of the affected region. Although droughts can persist for several years, even a short, intense drought can cause significant damage and harm the local economy.  Many plant species, such as Cacti, have adaptations such as reduced leaf area.  Most arid ecosystems have inherently low productivity.
• 4.
  (i) : Thishappens when the actual rainfall in an area is significantly less than the climatological mean of that area. The country as a whole may have a normal monsoon, but different meteorological districts and sub-divisions can have below normal rainfall. The rainfall categories for smaller areas are defined by their deviation from a meteorological normal rainfall of that region: • Excess: 20% or more above the normal annual rainfall • Normal: Upto +/- 19% above/below of normal annual rainfall • Deficient: 20% to 59% below normal annual rainfall • Scanty: 60% or more below normal annual rainfal
• 5.
  A marked depletionof surface water causing very low stream flow and drying of lakes, rivers and reservoirs. Inadequate soil moisture resulting in acute crop stress and fall in agricultural productivity
• 9.
  Economic Impacts Economic impactsare those impacts of drought that cost people (or businesses) money. Here are just a few different examples of economic impacts: • Farmers may lose money if a drought destroys their crops. • If a farmer's water supply is too low, the farmer may have to spend more money on irrigation or to drill new wells. • Businesses that depend on farming, like companies that make tractors and food, may lose business when drought damages crops or livestock. • People who work in the timber industry may be affected when wildfires destroy stands of timber. • Businesses that sell boats and fishing equipment may not be able to sell some of their goods because drought has dried up lakes and other water sources. • Power companies that normally rely on hydroelectric power (electricity that's created from the energy of running water) may have to spend more money on other fuel sources if drought dries up too much of the water supply. The power companies' customers would also have to pay more. • Water companies may have to spend money on new or additional water supplies. • Barges and ships may have difficulty navigating streams, rivers, and canals because of low water levels, which would also affect businesses that depend on water transportation for receiving or sending goods and materials. • People might have to pay more for food.
• 10.
  Environmental Impacts Drought alsoaffects the environment in many different ways. Plants and animals depend on water, just like people. When a drought occurs, their food supply can shrink and their habitat can be damaged. Sometimes the damage is only temporary and their habitat and food supply return to normal when the drought is over. But sometimes drought's impact on the environment can last a long time, maybe forever. Examples of environmental impacts include: • Losses or destruction of fish and wildlife habitat • Lack of food and drinking water for wild animals • Increase in disease in wild animals, because of reduced food and water supplies • Migration of wildlife • Increased stress on endangered species or even extinction • Lower water levels in reservoirs, lakes, and ponds • Loss of wetlands • More wildfires • Wind and water erosion of soils • Poor soil quality
• 11.
  Social Impacts Social impactsof drought are ways that drought affects people’s health and safety. Social impacts include public safety, health, conflicts between people when there isn't enough water and changes in lifestyle. Examples of social impacts include: • Anxiety or depression about economic losses caused by drought • Health problems related to low water flows and poor water quality • Health problems related to dust • Threat to public safety from an increased number of forest and range fires • Reduced incomes • People may have to move from farms into cities, or from one city to another • Fewer recreational activities
• 12.
  Droughts in India Inthe past, droughts have periodically led to major Indian famines [A severe shortage of food (as through crop failure) resulting in violent hunger and starvation and death] the Bengal famine of 1770, in which up to one third of the population in affected areas died; the 1876–1877 famine, in which over five million people died and the 1899 famine, in which over 4.5 million died.
• 13.
  Victims of theGreat Famine of 1876–78 in India, pictured in 1877. People waiting for famine relief in Bangalore. From the Illustrated London News, (20 October 1877) A contemporary print of the Madras famine of 1877 showing the distribution of relief in Bellary, Madras Presidency. From the Illustrated London News, (1877)