The historic drought of the west in 3 maps
By John Keefe and Rachel Ramirez, CNN
(CNN) – An unprecedented multi-year drought is worsening in the west amid record heat and drought, which scientists see as a clear sign of how the climate crisis is affecting not just the weather but water supplies as well. Food production and power generation.
Despite some good rainfall in the southwest, new drought numbers show worsening and worsening drought in the west across the board, according to the US Drought Monitor. Some drought affects more than 95 percent of the West, and nearly two-thirds of extreme or exceptional drought – the two worst categories.
Six states are completely in drought.
In the United States, the drought has almost doubled last year since then. About 25% of the land was in drought conditions in July 2020; since this week almost half have been in drought.
In addition to mandatory water restrictions already in place, some states face even tighter cuts amid the drought as water levels along the Colorado River sink.
Climate change plays a key role in these worsening crises: drought and extreme heat fuel wildfires; The reduced snowpack and the lack of significant rainfall are exacerbating water needs for millions of people, as well as for agriculture, ecosystems and deteriorating infrastructure.
More than 95% of the west has been hit by drought, the largest area ever recorded. More than 65% of the region is in “extreme” or “exceptional” drought – the two worst categories – and expanded 60,000 square miles, or about the size of the state of Georgia, in July.
There are six states that are fully affected by drought: California, Oregon, Nevada, Utah, Idaho, and North Dakota.
While southwest monsoon rain showers improved conditions in Arizona, New Mexico, and southwest Colorado, it brought little relief. Elsewhere, the drought intensified in the northern Rockies, and particularly in the Pacific Northwest, where the numbers are dire and it has practically stopped raining.
While the Bootleg Fire, the largest active forest fire in the country, rages in southern Oregon, about 17% of the state is currently in an exceptional drought – a number that nearly quadrupled in a month and the highest for the state ever . In Washington state, which had never experienced an exceptional drought until last week, it has now exploded, covering more than a quarter of the state. It is also a leader in the country with poor ratings for pastureland, spring wheat, and barley.
Many of the west’s largest reservoirs and lakes continued to see shocking declines. Lake Mead, a reservoir on the Colorado River behind the Hoover Dam, fell 135 feet below its 2000 level when it was last considered full.
Meanwhile, the Flaming Gorge Reservoir in Wyoming and Utah is releasing water to raise Lake Powell’s water level to protect its hydropower generating capacity. In Utah, too, the surface height of the Great Salt Lake decreased, building on the previous record low of 1963.
As the planet warms, drought and extreme heat will also fuel deadly forest fires. Several studies have linked rising carbon dioxide emissions and high temperatures to increased combustion area in the west, particularly in California.
The west experienced extremely low rainfall and snowfall last year, compounded by drastically high temperatures. Less rain and increasing heat waves have led directly to droughts and water shortages.
The southwest monsoon, which began in mid-July, is expected to provide some relief in this region. Still, the drought monitor reports that the recent rain “provided limited relief from the drought”. In some cases, the agency reports, “moisture has seeped several meters into the ground.”
As climate change accelerates and winter temperatures rise, snowfall will decrease. The high snow cover acts as a natural reservoir that alleviates drought, stores water during the winter months and slowly releases it again during the melting season in spring.
Stream and river course
Streamflow, a measure of how much water is carried by rivers and streams, is another important indicator of drought and its effects.
As drought conditions worsened in 2021, hundreds of streams and rivers are experiencing sub-par currents. More than 50 percent of the western measuring stations reported lighter currents than usual. Due to the low currents and warm water, fishing restrictions have also been introduced on many rivers in Montana.
Changes in the course of the stream affect the water supply for our own municipal needs, plant irrigation and electricity generation.