Rain feels easy to pin down. It begins when the first drop falls from the sky and ends when the last drop reaches its destination. We feel it when it hits our skin and hear it patter off the window when it falls at just the right angle.
But drought, which is just as inevitable in Texas, arrives without fanfare and reveals itself in different forms.
A homeowner might describe drought as the moment they begin seeing cracks split their front yard as parched soil separates. A farmer might notice drought when crops need more water. A hydrologist may say drought begins when low water supply becomes evident in the water system.
So, who is right?
The word “drought” dates back to before the 12th century, when it was defined as "a period of dryness, especially when prolonged,” according to the Merriam-Webster Dictionary. The National Integrated Drought Information System, NIDIS, defines drought as a deficiency of moisture that results in adverse impacts on people, animals, or vegetation over a sizeable area.
Drought is essentially less precipitation (rain or snow) than normal over time. It can last weeks or years and vary in severity. From a slight lack of rainfall that leaves brown landscapes to ground-cracking, lake-draining extremes with lasting, long-term effects.
Unfortunately, you can’t really see a drought coming. Drought has no clear beginning like other natural hazards, such as floods, tornadoes, or hurricanes.
And drought affects us in so many ways. We need water to grow the food we eat, keep power plants running to provide electricity, and quench thirst. Drought can contribute to insect outbreaks, increased wildfires, and altered nutrient levels in the water, all of which affect agricultural production, according to the NIDIS.
Droughts can degrade critical ecosystem functions, from reduced plant growth to landscape-level transitions such as a forest being replaced by grassland. As droughts lower water levels, warmer temperatures and soil runoff can lead to algal growth, lower dissolved oxygen levels, and other effects that pose health risks for humans and aquatic life, according to NIDIS.
These impacts can be temporary or permanent.
Some drought definitions are conceptual, which can be important in creating drought policy, according to the NIDIS. Others are operational, describing how drought functions or operates in measurable ways.
The main forms of drought are considered:
- Meteorological drought: When dry weather patterns dominate an area.
- Hydrological drought: When low water supply becomes evident in the water system.
- Agricultural drought: When crops become affected by drought.
- Socioeconomic drought: When drought affects the supply and demand of various commodities.
- Ecological drought: When drought affects the natural ecosystems beyond its ability to adapt, harming biodiversity.
Often called a “creeping phenomenon,” drought is also difficult to predict and monitor, and due to climatic differences, what might be considered a drought in one part of the country may not be somewhere else, according to NIDIS.
The 1930s “Dust Bowl” drought remains the most significant drought in the U.S. historical record, meteorologically and agriculturally, according to NIDIS.
The National Oceanic and Atmospheric Administration and its partners track drought and dryness through the production of the U.S. Drought Monitor, which is used by policymakers, researchers, and the public to monitor drought conditions. You can view the U.S. Drought Monitor here.
Since drought is a normal part of Texas’ water cycle, the Texas Parks and Wildlife Department has a section on its website called the Drought Survival Kit where they discuss planting native plants, the state of water, and many other resources.
The more you know, the better you can prepare. Drought is always on the horizon.