Wednesday, September 01, 2021

Wet & Dry America

Around half of the United States is currently experiencing drought conditions. Parts of North Dakota, South Dakota, Minnesota, Iowa and Nebraska are facing extreme drought conditions. This drought isn't exactly unexpected. In recent years the western half of the United States has seen ever decreasing levels of precipitation leading to increasing incidence of drought. Not something that has been troubling the eastern US.

You can explore the current and historical drought conditions on Esri's interactive Drought Aware map. Esri's Drought Aware map allows you to view the latest drought conditions across the United States and also view historical drought records. The map uses data from NOAA's Drought Monitor to show all the areas of the United States currently experiencing drought conditions and the severity of those drought conditions. As you can see from the screenshot above the map currently shows drought conditions in much of the west.


The reason why the western half of the United States has been experiencing increasing levels of drought in recent years is due to global heating and falling levels of precipitation. In the western half of the country climate change has led to less rain. 

Interestingly global heating has led to opposing conditions in the eastern half of the United States, which in recent years has been seeing increasing levels of precipitation. You can explore this divide in more details in the New York Times' These Maps Tell the Story of Two Americas: One Parched, One Soaked. The screenshot above shows the change in annual precipitation in the last 30 years, when compared to the 20th Century average.

As you can see from the NYT's map the western half of the United States is becoming drier at the same time that the eastern half of the country is becoming wetter. According to the Times this conforms to climate change predictions which broadly suggest that as the planet becomes warmer historically wet places will get wetter and drier places will get drier.

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