Over 50% of Earth's 'Rivers' Actually Stand Still or Run Dry Every Year
Our traditional idea of a river, an endlessly flowing stream of water, needs a rethink, scientists argue in a new study.
Even when a river runs dry, they say, it's still a river. These winding watercourses shouldn't have to flow all year round to receive our attention and protection. In fact, most of them don't.
In new research, scientists found at least 51 percent of all rivers worldwide stop running for at least one day per year.
In colder climates, rivers may temporarily freeze up, and in warmer climates, water may evaporate to stall flow. In Australia, for instance, 70 percent of the rivers are thought to be non-perennial.
It's the first time researchers have attempted to map all the non-perennial waterways in the world, and as it turns out they're ubiquitous.
Almost every river network on our planet hosts a channel that periodically stops flowing, from "Himalayan snow-fed creeks to occasionally water-filled Saharan wadis". The nearest river or stream for more than half the world's population stops flowing at some point in the year. ...
Previous studies have found non-perennial rivers are generally considered less valuable and less worthy of conservation. Today, many are unnamed and missing from maps, but that doesn't mean they aren't important. ...
Over the past 50 years, global warming and land use changes have stopped the flow of more and more rivers and streams. Even parts of the Nile in Egypt, the Indus in Asia, the Yellow in China, and the Colorado River in North America have started to experience stops and starts of flow. ...
