During dry and hot weather periods, it is common to find dry and cracked earth without even a single shed of water or wet areas. Lakes, rivers, and streams may as well run dry. Well, these are the typical earth conditions that define drought in layman terms.
Drought can simply be defined as extended periods of precipitation shortage, normally for a season or more resulting in water deficiency for some human activities or environmental sustainability. Human activities such as farming, irrigation, or domestic uses of water are normally highly impacted during droughts.
Plant and animal life are similarly affected. Accordingly, drought is a natural event arising due to less precipitation than expected thus defining the intricacies witnessed when the demands for water supply are higher than the available water for some activity, humans, or the environment.
Causes of Drought
- Rainfall or Precipitation Deficiency
Droughts take place whenever there is prolonged periods of rainfall deficiency for a season or more and usually when there is a lack of anticipated rainfall or precipitation. When a region goes for long periods without any rain, especially for more than a season, then the situation leads to dry conditions and water deficiency which qualify as drought.
Farmers, for instance, plant in expectation of rain and so when it doesn’t rain as expected, drought conditions are experienced. In such cases, it is frequently termed as agricultural drought.
- Human Causes
Human activities play a relatively significant role in the management of the water cycle. Human acts such as deforestation, construction, and agriculture negatively impact the water cycle. Trees and vegetation cover are essential for the water cycle as it helps to limit evaporation, stores water, and attracts rainfall.
In this sense, deforestation – clearing vegetation cover and cutting down trees increases evaporation and lessens the ability of the soil to hold water leading to increased susceptibility of desertification. Deforestation can also influence the occurrence of dry conditions since it reduces forest’s watershed potential. Construction and agricultural activities may as well reduce the overall supply quantity of water, resulting in dry spells.
- Drying out of Surface Water Flow
Lakes, rivers, and streams are the primary suppliers of downstream surface waters in various geographical regions around the globe. In extremely hot seasons or because of certain human activities, these surface water flows may dry out downstream contributing to drought – meaning the demands for water supply become higher than the available water.
Irrigation systems and hydro-electric dams are some of the human activities that can significantly diminish the amount of water flowing downstream to other areas.
- Global Warming
Human actions have contributed to more and more emissions of greenhouse gasses into the atmosphere thus resulting in the continued rise of the earth’s average temperatures. Consequently, evaporation and evapotranspiration levels have risen, and the higher temperatures have led to wildfires and extended dry spell periods. The global warming situation tends to exacerbate the drought conditions. Some of the worst droughts witnessed in sub-Saharan Africa have been associated with global warming and climate change.
Effects of Drought
The effects of drought are widespread and have devastating effects on the environment and the society as a whole. Water use is part and parcel of almost every human activity as well as the life of plants and animals. On this basis, extended deficiency of water can affect the society in various ways both directly and indirectly. The effects can therefore generally be categorized as environmental, economic, and social.
- Environmental Impacts of Droughts
Animal and plants die off as a consequence of drought. Mainly, the damages arise out of extensive destruction of the wildlife habitats and reduction in water quality and quantity. Some plants and animals may completely fail to recover after the drought. The overall climate, the rocks, and soils are also affected, negatively impacting various living and non-living factors.
- Drying out of water bodies
Surface waters such as lakes, rivers, ponds, creeks, streams and lagoons dry out during extended dry conditions which destroy natural habitats. Most especially, aquatic life and other wildlife dependent on these water bodies die or become endangered, destroying the entire food chain and alters the ecosystem.
- Reduction in soil quality
Soil moisture, essential for soil microbial activities, is reduced in drought conditions. As a result, soil quality is lowered because of minimized organic activity and continued dry spell which kills soil organisms. The end result is dry and cracked soil and it even becomes easier for decertification to occur.
- Unsuitable conditions for plant and vegetation survival
Drought conditions make it unsuitable for plants and vegetation cover to survive. Besides, fertile lands are lost as a result of drought, and in consequence, desertification sets in. Desertification is whereby the lands become infertile and bare, frequently as a result of overgrazing and is exacerbated by drought which makes it difficult for such lands to recover.
- Migration and even death of Animals and Wildlife
Animals and wildlife are forced to migrate in drought conditions since they have to move for long distances to get water and food. The prevailing circumstances during droughts also make it difficult for the survival of the animals. When the wildlife and animals migrate, they end up in new locations where they can be vulnerable, endangered because of new threats. This leads to loss of biodiversity and disruption of the natural ecosystems.
- Economic Impacts of Droughts
The economic impacts of drought are realized from monetary and business losses incurred during droughts by governments, businesses, families, and at the individual level. These are some of the examples of economic effects of droughts
- Increased budgetary spending by farmers
During droughts, farmers spend more money on crop irrigation so as maintain crop yields. Also, lots of water has to be availed for watering the farm animals to ensure the daily water consumption standards are met. Hence, farmers have to spend more money to buy water or drill wells to keep the crops and livestock nourished with enough water.
- Reduced crop yields
Often, low crop yields are experienced during drought periods. Therefore, farmers usually undergo major economic losses because of low crop yields. They pay for lots of inputs and labor, but the outcomes are less.
- Industrial and governmental losses
Industries and businesses in farm equipment manufacturing and merchandising respectively loss millions of dollars when farmers lack the money to buy their resources. Governments, on the other hand, have to allocate more money and spend even more for drought mitigation as they have to cushion the farmers and the entire society from the adverse impacts of the droughts. Such governmental monetary spending includes funds for emergency supplies, seed funds, and availing other relevant drought mitigation resources.
- Higher energy cost for economies dependent on hydro-power
Extended dry spells can translate to lowered water levels in rivers and dams used to generate hydro-power. This means higher costs of energy for businesses because the hydro-energy companies are driven to operate below capacity.
Businesses at times have to use fuel-powered generators which result in higher business operation costs. At the same time, increased energy demands lead to increased cost of grid energy, which leads to economic losses both for energy industries and businesses.
- Social Impacts of Droughts
Social implications are possibly the most felt effects of drought. They are the direct effects to people and communities. They include
- Outbreak of waterborne diseases
Since water scarcity is high during drought conditions, water quality significantly depreciates. This means the availability of clean water for drinking and water for sanitation and cleaning may not be sufficient. Droughts also increase the concentration levels nutrients, chemicals, and solid particles or impurities in surface waters. As a result, managing and preventing waterborne diseases such as typhoid and cholera becomes increasingly difficult, especially in poor regions.
- Hunger, anemia, malnutrition, and deaths
Hunger, anemia, malnutrition and deaths of people are often witnessed in drought-stricken areas. Drought is a great causal factor for low food production, thus, when experienced in poorer regions the effects of malnutrition, hunger, anemia and mortalities are compounded since there is little food available for consumption.
Often, it is as a result of lack of sufficient food nutrition that directly contributes to diseases and health vulnerability. Common cases of hunger, anemia, malnutrition, and mortalities are recorded in poorer nations.
- Migration of people and anxiety
People are forced to shift to other places in search for better living conditions during droughts. This contributes to loss of livelihoods and disorients small-scale farmers who are dependent on their farm produce. People forced to migrate also undergo lots of stress, anxiety and are compelled to indulge in strenuous activities to provide for their families. Women, children, and the elderly are the most affected.