Drought Hazard Overview

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).  Drought can even co-exist with record rainfall!

 


 

Defining Drought, Drought Response and Drought Mitigation

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.

There is not a single definition of drought to succinctly describe the progressive nature of drought development. Most often drought is defined by a combination of several definitions for increasing drought severity that are based on meteorological, agricultural, hydrological and socioeconomic effects, as outlined below.

Meteorological Drought

Meteorological measurements are generally the first indicators of drought development. This category of drought is often defined by a period of precipitation deficit that is outside of a “normal” range over a defined period of time.

Agricultural Drought

Agricultural drought occurs when there is not enough soil moisture to meet the needs of a particular crop at a particular time. Agricultural drought develops at some point after meteorological drought and is identified by linking the characteristics of a meteorological drought to agricultural impacts. .

Hydrological Drought

Hydrological drought refers to the deficiencies in surface and subsurface water supplies. It is measured as streamflow and as lake, reservoir and groundwater levels. There is a time lag between lack of rain and diminished quantities of water in streams, rivers, reservoirs and aquifers. .

Socioeconomic Drought

Socioeconomic drought occurs when physical water shortage begins to affect people, individually or collectively. This category of drought is manifested by adverse impacts to the health, well-being and quality of life of the people, or when drought begins to affect the supply and demand of an economic product.

 

 


Kentucky State Drought Mitigation and Response plan

Released in 2008
by Kentucky Drought Mitigation and Response Advisory Council

Link to Kentucky State Drought Mitigation and Response plan, chapter 7. http://water.ky.gov/wa/Documents/State%20Plan_Final.pdf


State Hazard Mitigation Plan – Drought

Link to the State Hazard Mitigation PlanDrought Risk Assessment for complete information and maps.

 


Planning for Drought

The Planning for Drought Resilience Fact Sheet describes how drought resilience can be part of hazard mitigation planning. It also shows how FEMA’s work in mitigation planning supports the 2016 Memorandum and Federal Action Plan on Building Capabilities for Long-Term Drought Resilience.

 


 

Tips for During a Drought

Always observe state and local restrictions on water use during a drought.  If restricted, for example, do not water your lawn, wash your car, or other non-essential activities, to help ensure there is enough water for essential or emergency uses. 

Apply chemical pesticides and fertilizers carefully – read the label.  Chemicals, especially those applied in dry form, can stay dry in a drought and be blown by the wind to sensitive areas.  If over-applied, they can accumulate and eventually wash away in concentrated amounts when the drought ends, possibly causing greater harm.  Always follow the directions on the pesticide label. 

Be aware of dust-related health problems.  Extended periods of dry weather can increase dust or other fine particles in the air we breathe, and possibly cause or worsen existing health problems. 

A drought can make hot weather feel even more severe.  Be sure you are prepared to protect yourself and others during hot, dry spells.