National Drought Mitigation Center

Drought Basics

Drought is a hazard of nature. We can’t see it ignite, like a fire, or predict where it is likely to touch down, as we do a tornado. Like its natural hazard cousins, however, drought can leave a trail of destruction that may even include loss of life.

And while we might refer to a fire’s crackle or the roar of a tornado, a drought hazard does not announce its arrival. In fact, those familiar with drought call it a “creeping phenomenon,” because what may first appear to be merely a dry spell can only be discerned in hindsight as the early days of a drought.

Drought’s stealthy reputation is also based on the way its effects vary from region to region. A week without rain might be considered a drought in a tropical climate like Bali, while a gap of only seven days between rains might be unusual in Libya, a desert area where annual rainfall is less than seven inches(180 millimeters).

In the most general sense, drought is defined as a deficiency of precipitation over an extended period of time(usually a season or more), resulting in a water shortage. The effects of this deficiency are often called drought impacts. Natural impacts of drought can be made even worse by the demand that humans place on a water supply.

Planning for Drought

Making preparations before a drought begins

In areas where floods are frequent, houses are often built on platforms several feet above the ground. In earthquake-prone regions, policies may be put in place to ensure that buildings are less vulnerable to collapse if a quake strikes.

Similar preparations can increase the likelihood of an individual or community managing a drought hazard in a way that minimizes overall losses.  Individual farmers or ranchers, communities or regions can begin a planning process to:

  • identify water-dependent functions of a farm or community
  • prioritize water-dependent functions
  • determine steps to adapt those functions if water supplies begin to drop

Using the U.S. Drought Monitor to understand drought severity

In the United States and some other countries, there are maps showing which parts of the country are in drought, and the intensity or level of drought an area may be experiencing. The Drought Monitor map for the United States is updated every week. A tutorial video shows more about how information in the U.S. Drought Monitor is used for management of farms, ranches, cities, businesses and natural resources.

Watch video