DROUGHTS

WHAT IS A DROUGHT?

The word ‘Drought’ is always a difficult one to define, because it is often used in more than one context. In simple terms, it is the absence of water for a long period of time, at a place where it is considered ‘not normal’ compared to its usual conditions.

The distribution of all the water on the earth’s surface is not even. Some places have lots of fresh water (rivers, lakes, lagoons, ponds etc.) and are continuously replenished by rainfall, runoffs and water from underground. Others places too are known to have very little water.

With this in mind, we can describe a drought scenario to be ‘A relatively long time where there is not enough water than there usually is, as a result of dry weather, to support human, animal and plant life

it becomes an issue when it begins to affect water supply for irrigation, municipal, industrial, energy, and ecosystem function. People often do not see droughts as natural disasters like tornadoes, hurricanes or floods, because they do not have usual immediate destructive ability, but they can be very catastrophic in the long run. Server droughts can have very serious consequences.

WHAT ARE THE TYPES OF DROUGHTS?

There are some indicators that experts use to determine if a condition can be called a drought. Here are some common scenarios of droughts: Meteorological drought: This kind is usually determined by the general lack of precipitation. It is expressed in relation to the average conditions of the region over a long period of time. It is usually an indicator of potential water crisis if the condition is prolonged. Agricultural drought: Here, crops, animals and evapotranspiration are affected It is often signs one sees, but not before a hydrological drought. Hydrological drought: This is when there is a deficiency of surface water and ground water supply in a region, often as a result of less precipitation. Hydrological drought does not usually occur at the same time as meteorological drought  Socio-economic drought: This condition is when some supply of some goods and services such as energy, food and drinking water are reduced or threatened by changes in meteorological and hydrological conditions. Sometimes it is even made worse by growing populations.

What causes drought?

  • Lack of rainfall (or precipitation) Droughts can occur when there is lack of ‘expected’ precipitation (rain and snow). Some regions can go for months without any rain, and that would be ‘normal’ for them. Farmers plant in anticipation of rains and so when the rains do not come, and irrigation infrsastructure is absent, agricultural drought occur.

  • Surface water flow Some regions are also well distributed with streams and rivers that have their sources from far away mountains and watersheds. These surface waters may dry out. Hydro-electric dams and irrigation systems are some of the economic activities that can reduce the amount of water flowing to other areas downstream.
  • Human factors Forests play a key role in water cycle, as they help reduce evaporation, store water and also contribute to atmospheric moisture in the form of transpiration. This means, deforestation will expose surface water to more evaporation. It will also reduce the ability of the ground to hold water and make it easier for desertification to occur.

WHAT ARE THE MAIN EFFECTS OF DROUGHTS?

  • ECONOMIC IMPACT
  • Farmers will have to spend more money to irrigate the crops and provide water for livestock on animal farms. Low crop yield means farmers lose a lot of money-
  • Less or no rains mean dryer conditions and more bush fires. Businesses spend more on electric generators or close production if hydro-energy companies operate below capacity.
  • Businesses connected to water recreation, such as beaches and lake side activities may close down.
  1.  ENVIRONMENTAL IMPACT Here are a few examples:
  • Droughts lower the quality of soils, because there is less organic activity. Water bodies (lakes, creeks, ponds, lagoon and lakes) dry out, and water animals die. This is called habitat destruction.
  • Desertification is when fertile lands (vegetation lands) become bare and infertile, often as a result of overgrazing, deforestation and other economic activity. Droughts make this process even worse.
  • The health and quality of Freshwater Biomes such as lakes and ponds, rivers and streams, wetlands are affected and living organism in there are also endangered. Animals (wildlife) migrate long distances in search of water.

C)SOCIAL IMPACT

Health has a direct link to the water supply of any settlement. Clean water for drinking and water help society prevent and manage diseases.

People migrate to other places in search of better living conditions. This makes a region in drought vulnerable, as many of its young and working population are forced leave. Farm families suffer more when family members migrate. Droughts in more rural areas of the world causes strain on family lives.

Earth_Hour_2015_How_do_floods_and_droughts_affect_our_environment_8211_Year_3_038_4_Student_Worksheet

Earth_Hour_2015_How_do_floods_and_droughts_affect_our_environment_8211_Year_3_038_4_Teacher_Worksheet

2004-11-drought

p67worksheets_drought

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