Droughts occur when a long period of abnormally dry weather leads to a severe water shortage. Droughts are also often caused by the activity of humans and can have devastating effects.
Human activities causing drought
Human activities that can help trigger droughts include:
- Widespread cutting down of trees for fuel reduces the soil’s ability to hold water – drying out the ground, triggering desertification and leading to drought.
- Constructing a dam on a large river may help provide electricity and water to irrigate farmland near the reservoir. However, it may also cause drought downstream by severely reducing the flow of water.
Effects of drought
Parched ground during drought in Namibia
- Droughts endanger lives and livelihoods through thirst, hunger (due to crops dying from lack of water) and the spread of disease.
- Millions of people died in the 20th century due to severe drought and famines. One of the worst hit areas was the Sahel region of Africa, which covers parts of Eritrea, Ethiopia and the Sudan.
- Droughts and famines can have other geographical impacts. If drought forces people to migrate to a new home it could put pressure on resources in neighbouring countries.
- Droughts can have a severe impact on MEDCs as well as LEDCs. Droughts have caused deaths in Europe in recent years – especially amongst the elderly. In the UK in summer 2006, there were hose-pipe bans and campaigns to make people save water.
Case study: drought in the Sahel
Map showing location of Sahel
Food for distribution Yabelo area, Southwest Ethiopia
The Sahel region of Africa has been suffering from drought on a regular basis since the early 1980s. The area naturally experiences alternating wet and dry seasons. If the rains fail it can cause drought.
In addition to natural factors, the land is marginal. Human activities such as overgrazing, overcultivation and the collection of firewood can lead to desertification, particularly when combined with drought conditions.
The result is crop failure, soil erosion, famine and hunger: people are then less able to work when their need is greatest. It becomes a vicious circle and can result in many deaths, especially among infants and the elderly. In Niger in 2004, the situation was made worse when a plague of locusts consumed any remaining crops. In these cases, people rely on food aid from the international community.
On its own, food aid is unsustainable in the long term. What is really needed is development aid, which involves educating the local community in farming practices.
Case study: the impact of drought in the UK (2004)
The years 2004-06 were one of the driest periods on record in the UK.
South East England is particularly vulnerable to drought because it has a high population density. There are 13 million people living in the region and the demand for water resources is high. There are few reservoirs, which means there is a heavy reliance on groundwater supplies. Two consecutive dry winters meant that these supplies were not replenished.
Drought warning in Devon
- Hose-pipe bans were introduced in an effort to conserve water.
- Groundwater fell to its lowest level on record.
- Some rivers dried up.
- Low flow in rivers meant that pollution had a greater impact on the environment.
- Fish were more likely to die because of low flow, low oxygen levels and higher water temperatures.
- Kew Gardens introduced a range of measures to conserve water, eg only watering newly planted trees and newly turfed areas.