Taxonomy term

river

Due diligence in river incision data

As great equalizers of topography, rivers and streams whittle down landscapes by alternately scouring away broad flat swaths of sediment and rock, and incising deeply through them. If a landscape — a mountain range, for example — is being uplifted by tectonic forces, this whittling occurs even faster. River incision rates in particular are thus often used to infer past rates of rock uplift. But determining incision rates themselves is not clear-cut. In a new study in Geology, scientists look at one complicating factor in such calculations, what the authors call the “unappreciated effects of streambed elevation variability” on measuring river incision rates.
 
21 Nov 2015

Travels in Geology: Rafting the Pacific Northwest's heavenly Hells Canyon

Few roads and only steep, difficult trails run down into Hells Canyon — the deepest canyon in North America — which forms part of the border between Oregon and Idaho. But the location is popular among boaters, whitewater rafters and fishermen, and a trip down the river reveals some spectacular rocks.

18 Sep 2015

Soil may supply surging streams after earthquakes

Earthquakes don’t just rattle buildings and psyches — they shake up the hydrological cycle too. Scientists have long noticed spikes in streamflow following big quakes, but they have yet to pinpoint the causes of these surges. While most proposed explanations conjure different ways of uncorking groundwater reservoirs, a new study suggests that at least some of this extra water may actually get shaken out of the soil.
 
09 Jul 2015

Sediment load shapes rivers

The amount of sediment carried in meandering rivers influences how quickly the bends in those rivers migrate back and forth, according to recent research in Nature Geoscience addressing a longstanding question regarding river evolution. Meanders form when flowing water erodes one riverbank while simultaneously depositing sediment on the opposite bank, gradually creating more and more pronounced U-shaped bends. Sometimes, the rivers cut new channels across the narrow necks of such bends, isolating the abandoned meanders to form distinctive oxbow lakes. 
 
04 Jul 2015

Can dam releases restore river ecosystems?

Scientists and dam managers are studying how the very dams that disrupt river ecosystems can be used to restore them using controlled releases of water.

18 Mar 2015

Mississippi sand still abundant

Flood control measures along the Mississippi River have likely saved countless lives, but the effects of upstream dams and containment on the river’s delta have been ecologically catastrophic: In the past 80 years, more than 5,000 square kilometers of wetlands along the Louisiana coast have been starved of vital sediment and drowned. Now, researchers have found that the lower river contains a significant reservoir of the sand needed to mitigate land loss at the river’s mouth — if  it can be diverted downstream.
 

01 Sep 2014

Warm river water melted Arctic sea ice

In September 2012, the area of the Arctic Ocean covered by sea ice was the smallest on record since satellite monitoring began in 1979. Several factors are thought to have contributed to that summer’s diminished ice, including a large cyclone in August that brought warmer ocean waters into the area and broke up the ice and a longer-term trend of thinning and weakening sea ice. Now, researchers have found that at least one large burst of warm freshwater into the Arctic earlier in the summer probably played a role as well.
 

23 Aug 2014

Benchmarks: June 22, 1969: The Cuyahoga burns

It was a relatively small fire. In terms of damage and duration, the city of Cleveland had seen far worse in the 173 years since its founding. In fact, the blaze on June 22, 1969, only warranted a mere 181 words in the Cleveland Plain Dealer. But it was not an ordinary fire: It was the Cuyahoga River that burned. And the event started a movement that revolutionized the United States’ commitment to environmental protection.
 
03 Jun 2011

Benchmarks: November 27, 1873: Red River logjam removed for good

Throughout the 1800s, America’s eastern and southeastern coastal rivers acted as highways for shipping. Generally winding with shallow slopes, the rivers could be plied easily by barges and steamboats, but one particular water body — the main channel of the Red River that runs from Arkansas through Louisiana — thwarted the plans of shippers for much of the 19th century. A massive entanglement of logs, stumps and branches, known as the Great Raft, blocked the Red from Fulton, Ark, to about Shreveport, La. But on Nov. 27, 1873, after more than 40 years of trying, the raft was destroyed and boats could travel unimpeded down the main channel of the Red River.
 
05 Nov 2010

Down to Earth With: Matt Kondolf

As a fluvial geomorphologist teaching in the Landscape Architecture and Environmental Planning Department at the University of California at Berkeley, Matt Kondolf is an ambassador from the earth sciences to landscape designers and environmental planners. Kondolf’s research in river management ranges from the impacts of urbanization on runoff and sediment yield, to river restoration, to managing salmon populations and fishing. In classes like “Hydrology for Planners” and “Ecological Analysis in Urban Design,” he encourages up-and-coming environmental planners and designers to think carefully about the geologic processes that control river formation, as well as the roles that rivers play within ecosystems. He is also active in the policy discussions that are shaping California’s and the nation’s approaches to river management.

02 Jan 2010

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