These images provide information about the amount of heat on Earth’s surface. The National Oceanic and Atmospheric Administration, or NOAA, GOES-R (Geostationary Operational Environmental Satellites-R Series) and JPSS (Joint Polar Satellite System) series satellites can capture thermal infrared images of Earth. For example, satellite data were used to develop a tool that alerts farmers about upcoming flash droughts. One way to monitor droughts is from weather satellites in space. However, multiple soaking rains over several months are needed to truly return things to normal. One soaking rain may help improve drought conditions. Groundwater provides water to plants and can refill streams during non-rainy periods. Rains that soak into the soil can replenish the groundwater. The only way a drought can really end is with enough regular soaking rains or significant snow. If a thunderstorm hits during a drought, the rain can come too fast to be absorbed by the soil and the water may just end up going down a storm drain. Eventually, the unusual dry weather causes water supply issues, and the dry period becomes a drought. 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. The soil starts drying out and plants die. When a particular area gets less rain than usual, the soil gets much less moisture, too. But, the average yearly precipitation in Atlanta is about 50 inches. For example, in the deserts of the American Southwest, the average precipitation is less than 3 inches per year. However, over a period of many years, the average amount of precipitation in a region is fairly consistent. From season to season - and from year to year - the amount of rain or snow in a location can vary. Some regions are routinely wet and others are routinely dry. Rain and snow don’t fall evenly across Earth.
Droughts only occur when an area is abnormally dry. Just because a region is hot and dry doesn't necessarily mean it is going through a drought. Really hot temperatures can make a drought worse by causing moisture to evaporate from the soil. What causes a drought?Ī drought is caused by drier than normal conditions that can eventually lead to water supply problems. But it could take a much longer dry period to see a full drought that would affect a region’s water supply. The severity of the drought depends on the amount of time that a region receives below-average precipitation.įor example, a few weeks without rain could stress a farmer’s crops during the growing season. Credit: Public DomainĪ drought is a prolonged period with less-than-average amounts of rain or snow in a particular region. A close-up image of dry, cracked soil during a drought.
0 kommentar(er)
