DROUGHT

Drought is a condition that results when the average rainfall for an area drops far below the normal amount for a long period of time. This condition is also called drouth. Streams, ponds, and wells often dry up during a drought. Water supplies for agricultural, industrial, and personal uses are greatly reduced. Often the dry and crumbled topsoil is blown away by hot, dry winds (see Dust storm). In areas that are not irrigated the lack of rain causes farm crops to wither. Livestock may die. Extreme drought can lead to many human deaths. The deaths are rarely from starvation. They are usually from drought-related conditions. In time of drought, people become more vulnerable to disease, and less resistant to illness such as diarrhoea. In some parts of Africa as many as 25 per cent of children under the age of five died during droughts in the 1980's. Throughout the world, drought affects more people than does any other single type of disaster. And drought causes about 20 per cent of all disaster-related deaths.

Countries affected by drought

The continent currently most seriously affected by drought is Africa. The Sahel, a region south of the Sa­hara, and Ethiopia both suffered the worst effects of the catastrophic drought in the 1980's. Drought conditions persisted in this region through the early 1990's when Sudan, in particular, experienced severe famine. Food aid helped to relieve the famine. Nevertheless, many thousands lost their lives. In sub-Saharan Africa, where about 75 out of every 100 people live by agriculture, many farmers were forced to abandon their villages and look for work to support their drought-hit families.

Many people ended up in refugee camps, totally de­pendent on food aid. Others gave up scratching a living from the land and went to live in Africa's towns and cit-

Droughts occur in many developing countries of the world, but they need not necessarily result in severe food shortages, or famines. In India, many regions expe­rienced severe drought from 1971-1973. Maharashtra, one of the worst affected states, organized massive food-for-work schemes. At its peak, about 5 million peo­ple were employed on public works such as dam and road building. Not a single death was attributed to star­vation during this period. Other countries, such as Brazil and Kenya, have also adopted measures to try to reduce the damage done by droughts in those countries. Such measures have met with limited success.

Drought is not confined to countries in tropical and sub tropical regions. From December 1975 to August 1976 a so called "strong drought" covered northwestern Europe. Losses, especially in agriculture, were esti­mated in billions of U.S. dollars.

Areas of the United States have suffered three bad droughts in the 1900's. From 1931 to 1938 the Great Plains region experienced one of the worst droughts in its history, and the effect was felt throughout the coun­try. From 1950 to 1954 the Southwest and the southern Great Plains suffered a severe drought. The worst drought since the 1930s struck the Midwest, the north­ern Great Plains, and part of the Southeast in 1988. It caused serious damage to grain crops.

Major droughts have occurred in Australia 11 times since the mid 1800s, eight of them since 1900. A major cause of drought in Australia is the El Nino-southern os­cillation phenomenon, a disturbance of the air and sea currents of the Indian and Pacific oceans. Drought can occur anywhere in Australia, but more droughts occur in the drier interior than in coastal areas because the rainfall is less dependable further inland.

Drought control. 

The economic damage caused by drought can to some extent be contained by planning. In Australia, for example, when severe droughts cause great economic loss, the federal government usually of­fers financial assistance to farmers. Improved transport routes to enable farmers to move their stock from drought areas, or bring in relief fodder are among the new measures for controlling the effects of drought. The farmers themselves try to improve their properties as a defence against the climate. They extend irrigation schemes or drill for water. They put up more fencing to keep their pastures in better condition. They store fod­der in good years so that they will have food reserves in drought years. In some more remote areas they also plant an edible tree, called top feed.

Long-term measures to beat drought, such as the cre­ation of artificial lakes, have been suggested. Water evaporating from the lakes might set up a rainfall cycle. But climatologists doubt whether such an idea would have a long-term benefit on the climate.

Another method that has been tried for changing the climate in drought-affected areas is cloud seeding. To produce rain, iodine crystals are scattered among clouds from aircraft. The water-vapour molecules in the clouds cluster around the crystals and make them heavy. Eventually the overloaded crystals fall to earth as rain. Unfortunately, this method works well only in areas where rainfall readily occurs naturally.