A drought is caused by drier than normal conditions that can eventually lead to water supply problems. Really hot temperatures can make a drought worse by causing moisture to evaporate from the soil. Just because a region is hot and dry doesn't necessarily mean it is going through a drought.
Droughts only occur when an area is abnormally dry. Here's why:. Some regions are routinely wet and others are routinely dry. From season to season — and from year to year — the amount of rain or snow in a location can vary. However, over a period of many years, the average amount of precipitation in a region is fairly consistent. For example, in the deserts of the American Southwest, the average precipitation is less than 3 inches per year. But, the average yearly precipitation in Atlanta is about 50 inches.
When a particular area gets less rain than usual, the soil gets much less moisture, too. The soil starts drying out and plants die. When this pattern continues for several weeks, months or years, the flow of streams and rivers decreases and water levels in lakes, reservoirs and wells fall. Eventually, the unusual dry weather causes water supply issues, and the dry period becomes a drought.
Two men examine roots of alfalfa and grass hay hit by drought in Sidney, Montana. As overall temperatures increase more water evaporates and severe weather conditions increase. Landscapes and crops need more water to survive and overall the demand for water increases. This is why it is so important to consider changes in ET when discussing water savings.
You might be using more water or less water depending on weather conditions. Key events like El Nino or La Nina help contribute to drought in areas. All the water we ever had we have today and it is stored in the air or on land. Weather patterns move the water in the air around.
This is constantly changing. When soil moisture is depleted there is less evaporation of water to create clouds. Surface temperatures rise, more water is needed and less is available which contributes to a more severe drought.
When a region is growing rapidly the demand for water can exceed the supply. When weather conditions, temperatures or air patterns push a region toward a drought the demand for water by people can offset or worsen the situation depending on how the region reacts.
Excessive irrigation is an excellent of people contributing to a drought. Proper storage and collection of water is key to counter balancing this cycle and clearly in the scope of human management. Severe droughts also impact the migration of people. As countries continue to protect their natural resources people will move to water. The amount and timing of the movement can contribute to water issues not previously felt before. Richard is a water management evangelist.
There would be less water in the river for you and other people who live along the river to use. People can also play a big role in drought. If we use too much water during times of normal rainfall, we might not have enough water when a drought happens.
Earlier we learned that droughts are normal parts of climate just like floods, hurricanes, and tornadoes. That might sound strange to you if you have seen pictures of what floods, tornadoes, and hurricanes can do to houses, trees, and the land. Droughts, floods, hurricanes, and tornadoes are what we call natural hazards. We usually can't see drought coming. We can see water rising in a river, watch the wind pick up as a hurricane approaches, or see thunderclouds approaching. We also can turn on the television, radio, or internet to see storms on radar and find out what we should do to protect ourselves from storms.
This is why we often say that drought is a creeping natural hazard. Drought can sneak up on us because we might enjoy being outside in the sunshine and not having rain interrupt our plans. We can have several weeks of enjoying the sunny weather before we notice that our lawns or plants start to look brown.
More Contact Info Web Policy. Drought Center creates tool that could help detect emerging impacts by tracking news. Drought Monitor now searchable by tribal area. What is Drought? During a drought, ponds, lakes and rivers may begin to dry up.
What causes a drought? Weather and Climate. Water Cycle. Water and Weather on the Move. Causes of Drought.
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