Natural hazards: causes and effects. Lesson 7-Drought.

Drought has long been recognized as one of the most insidious causes of human misery. Today, it is the natural disaster that annually claims the most victims. Its ability to cause widespread misery is estimated to be increasing. While generally associated with semiarid climates, drought may occur in areas that normally enjoy adequate rainfall and moisture. In the broadest sense, any lack of water for the normal needs of agriculture, livestock, industry, or human population may be termed as a drought. The cause may be lack of supply, contamination of supply, inadequate storage or conveyance facilities, or abnormal demand. Drought is a condition of climatic dryness severe enough to reduce soil moisture and water below the minimums necessary for sustaining plant, animal, and human life. Drought usually is accompanied by hot, dry winds and may be followed by damaging floods. More socially relevant than technically correct is the definition used by Ari Toubo Eibrahim, the minister of agriculture in Niger, who has said that a drought is "Not as much water as the people need."