Northern Mexico has a historic water shortage. These maps explain why. – The Washington Post

Posted On : Published By : Tom Whipple

Water has become a sacred commodity in northern Mexico.

Reservoirs have been hitting the bottom of their basins. Taps have been running dry for millions of people in the city of Monterrey, where the water shortage was called a matter of national security. Water bills have skyrocketed.

People have sabotaged pipes that could divert water to other cities. Truck drivers delivering water have been kidnapped.

Ranchers in rural areas have lost livestock or sold their herds prematurely because they can’t feed them.

“People are making lines to obtain a few liters of water. … I wonder how it is possible that they reach this level?” said Víctor Magaña-Rueda, a climatologist at the National Autonomous University of Mexico. “In March, nobody was talking about the socioeconomic drought, and, all of a sudden, we realized that Monterrey was facing one of the worst droughts ever seen in the area.”

For more than a year, northern Mexico has experienced abnormally dry to exceptional drought conditions, but water shortages have become increasingly dire in recent months.

As demand has grown, researchers say a lack of rain and, especially, water mismanagement have led to one of the worst droughts in the northern half of the country. As populations continue to increase and temperatures keep rising, speeding up evaporation from the land surface, water problems will worsen without better adaptation.

Drought in Mexico leads to water rationing, theft

Dry conditions are not rare in northern Mexico. Much of the land consists of desert or is semiarid, typically receiving less than 30 inches of rain per year.

Rainfall this year has been lower than normal, however. Northeastern Mexico has been persistently dry since January, receiving no rainfall in some months, which is somewhat unusual even during the dry season.

The North American Drought Monitor shows drought conditions across Mexico, a finding that is primarily based on precipitation amounts; about half of the country is experiencing at least a moderate drought.

Oceanographer Benjamín Martínez López said some of the rainfall deficit results from the temporary presence of La Niña, which is characterized by a cooling of surface waters in the equatorial Pacific Ocean. The lower ocean temperatures are linked to fewer clouds, less rainfall, and more evaporation in northeastern Mexico.

Increased temperatures associated with human-caused climate change can also intensify evaporation, dry out soils and worsen drought. Mexico has warmed about 2.7 degrees Fahrenheit (1.5 degrees Celsius) since preindustrial times. The Intergovernmental Panel on Climate Change has documented an increase in drought in the region and expects this condition to worsen in the future as temperatures rise.