Deserts are dry, arid places that we typically associate with lack of water instead of its presence. So, the question “are there floods in the desert?” seem absurd at first glance. But, looking deeper, it actually isn’t nonsensical at all.
So, if there is water damage that claims Nevada’s desert, that will surprise a lot of people for sure. Let’s keep reading and find out why below.
When It Rains, It Floods in the Desert
Did you know that there are two major causes of death in the desert? The first one is obvious – dehydration – but the second one (i.e., drowning) not so much. Drowning in the desert is caused by flash floods.
Around one-fifth of the planet is covered with deserts, which receive about 10 inches (250 mm) of rainfall per year. This is equivalent to only 10% of the amount of rainfall that rainforests receive annually. (Rainforests get nearly 80 inches (or more than 2,000 mm) of rainfall yearly.)
Rainfall in the desert comes in the form of an annual monsoon, hurricanes or their remnants. Hurricanes, storms, cyclones or whatever you call them are common occurrences in the desert. For instance, remnants of such storms are frequent in the American Southwest, leading to heavy rains in places like Arizona and southern California. Deserts in the Arabian Peninsula also receive rain brought about by storms from the Indian Ocean, affecting Middle Eastern countries like Saudi Arabia, the United Arab Emirates, Yemen, and Oman. Meanwhile, in Australia, cyclones can come from both the Indian and Pacific Oceans and impact the country’s vast Outback.
According to The Weather Network, monsoon rains can be “intense, sometimes producing rainfall rates of [less than 1 inch] 20+ mm per hour.” While this amount doesn’t seem much, it can have deadly consequences in the desert.
While rainforests and other non-desert environments might have soil and vegetation that can absorb or soak up water, deserts don’t. Instead, they consist of clay or sandy, stony, or gravelly soil which repel water rather than absorb it. As a result, when rain falls, water simply runs off. So, monsoon season in the desert is also often flash flood season.
Flash Floods in the Desert
Most deserts lack drainage to rivers, lakes or oceans. (But, even those that are traversed by “exotic rivers,” like the Nile in Egypt, experience flooding too.) So, rainwater has no other course of action but to fill depressions or pool together in low-lying areas, such as wadis, arroyos and dry riverbeds. An example of this is the Black Rock Desert in Nevada, where the extinct Lake Lahontan is now a salt flat used for car racing.
Flash floods are a major concern even when desert skies are clear or when storms are raging from miles away. Writer Michael Branch shares in High Country News how he was surprised by a flash flood when moments before held only the good prospects of a brightly illuminated afternoon sky.
On this fateful day, he witnessed the birth of nearly a dozen waterfalls and the appearance of ghost rivers, which emerged suddenly and disappeared as quickly too. He writes: “In an environment such as this, the spontaneous appearance of creeks and rivers is as remarkable as was the sudden birth of eleven waterfalls on that strange, beautiful day down in the red heart of the Escalante. A flood here is not a matter of a river rising, but rather of a river appearing where none has existed in recent memory, and then vanishing almost as suddenly.”
Branch was fortunate for he knew exactly what to do in situations such as this. However, most flash floods can come unexpectedly upon the unprepared. For instance, in 2011, over a hundred people in Jeddah, Saudi Arabia lost their lives, along with the washing away of roads and buildings, during a sudden thunderstorm and flash flood.
Other Impacts of Desert Rain
Rain, and the resulting flash floods that typically come along with it, has been happening in the deserts for years. The impact of water in these dry and arid regions of the Earth can be seen in the landscape and flora and fauna.
Landscape Design
In the desert, water is like an architect or landscape designer. Those rock formations you see, such as buttes and mesas? They were formed by water patiently wearing away at them for many, many years. Alluvial fans, or those deposits of gravel, sand and other sediment that you’ll find at the bottom of these formations, were also created by water.
“In their sudden appearance and disappearance, and in the profound changes they’ve wrought in my home landscape, these recent floods have reminded me that this astonishing place has been shaped by sudden as well as gradual change,” reflects Branch.
Desert Blooms
Rainfall in the desert doesn’t always mean gloom and doom, however. Under the right conditions, rain becomes an author of magnificent floral displays.
Desert blooms represent a good flowering year that may only grace our eyes once in a decade or two. This rare event coincides with El Niño currents which bring warmer temperatures that result in more evaporation, which leads to more rainfall, Ana María Mujica, a professor at the Faculty of Agriculture & Forestry of Pontificia Universidad Católica de Chile (UC Chile), explains.
The rain is like the prince that wakes the flower seeds that have been sleeping for 5 to 10 years. But, the awakening of these little sleeping beauties also signal the emergence of insects, birds, and other species. “It is an ephemeral flowering, very short-lived, around which arises numerous species: birds, insects, reptiles, rodents,” Mujica shares. “It’s all related.”
María Fernanda Pérez, a professor at UC Chile’s Faculty of Biological Sciences, adds that you can only find some of these insect species in the flowering desert. And, “All it takes is a little water to awaken an entire ecosystem,” she adds.
Are There Floods in the Desert?
Flash floods in the desert usually come with debris, which could include sand, rocks, vegetation, and other loose materials. The steady but raging waters bring these debris along for the ride as the flood fills existing wadies or arroyos or create new ones.
In conclusion, as we have demonstrated, yes sometimes it does flood in the desert even though at first thought, we wouldn’t think so.