U.S. stream network is longer during annual high-flow conditions

Summary author: Walter Beckwith

2025-02-13

(Press-News.org) Rivers and streams may look permanent, but their lengths can change dramatically with the seasons, according to a new study. It reports that stream networks in the United States expand up to five times their low-flow size during wet conditions. The findings offer the first large-scale insights into how water dynamically moves through landscapes and provide a framework for forecasting climate-driven changes in stream networks, particularly in response to increasing storminess. Traditionally regarded as static landscape features, stream networks exhibit significant seasonal and storm-driven fluctuations in their total wetted length. For example, seasonal rainfall and snowmelt saturate the landscape, temporarily increasing streamflow and extending stream networks. Additionally, changes in surface topography and permeability can cause networks to expand or contract. This responsiveness of stream length to shifts in landscape wetness is termed "network elasticity." Alongside variations in wetness, it governs fluctuations in stream extent across drainage basins that influence sediment transport, nutrient cycling, gas exchange, and aquatic habitats. However, understanding stream network length variability has generally been limited to small-scale studies relying on field measurements – and to a handful of small drainage basins. Here, Jeff Prancevic and colleagues used a semimechanistic model to estimate stream network elasticity for 14,765 basins across the contiguous U.S. Prancevic et al. found that the median stream network is five times longer during annual high-flow conditions than during low-flow conditions, with regional differences influenced by hydroclimate and topographic sensitivity. Mountainous and humid regions tend to have more stable stream networks. The findings suggest that a basin’s topography and subsurface structure, which determine its network elasticity, are as crucial as climate factors in predicting fluctuations in stream length. Although the study focuses on the continental U.S., the authors note that the methodology, which only requires digital elevation models and streamflow data, could be applied more broadly.

Raw data files for this paper are available to news outlets interested in building their own data visualizations. Please contact Jeff Prancevic at jeffp@ucsb.edu for more information.

END

ELSE PRESS RELEASES FROM THIS DATE:

Seismic techniques reveal how intense storms in 2023 impacted aquifers in Greater Los Angeles

2025-02-13

Despite record rainfall in the region in early 2023, only a fraction of Southern California’s groundwater reserves has been replenished, researchers report. Their study, which leverages seismic noise data from across Greater Los Angeles, highlights the urgent need for improved monitoring and management of the state’s critical groundwater reserves. After enduring two decades of severe drought, California experienced an abrupt meteorological shift in water in 2023. A succession of 16 atmospheric rivers from late 2022 through early 2023, followed by the torrential ...

Elephant seals in the Pacific serve as deep-ocean sentinels, revealing patterns otherwise hard to measure

2025-02-13

Northern elephant seals may hold the key to unlocking the secrets of the open ocean’s twilight zone (~200 – 1,000 meters deep). According to a new study, these deep-diving creatures can help estimate fish abundance by providing a rare window into the elusive prey dynamics in one of the planet’s most mysterious and remote ecosystems. Ecosystems are dynamic, with resource fluctuations – natural or human-induced – shaping species interactions and food webs. These processes are well studied in terrestrial ecosystems but not in deep, open ocean ecosystems, ...

Depression linked with higher risk of long-term physical health conditions

2025-02-13

Adults with a history of depression gain long-term physical conditions around 30% faster than those without, according to research publishing February 13th in the open-access journal PLOS Medicine. Kelly Fleetwood of the University of Edinburgh, United Kingdom, and colleagues argue that their study suggests depression should be viewed as a ‘whole body’ condition, and integrated approaches should be used to manage mental and physical health. Depression is the most common mental health condition and ...

Los Angeles groundwater remained depleted after 2023 deluge, study finds

2025-02-13

The greater Los Angeles area has long been subject of intense seismographic monitoring. A network of highly sensitive seismometers peppers the region on a constant vigil for earthquakes. Now researchers at the Stanford Doerr School of Sustainability have developed a new way to use that existing infrastructure and its decades of data to estimate water levels in the region’s aquifers, which serve some 10 million residents of Los Angeles and Orange counties. The researchers analyzed the ...

Foraging seals enable scientists to measure fish abundance across the vast Pacific Ocean

2025-02-13

EMBARGOED until Thursday, Feb.13, 2025, at 2 P.M. U.S. Eastern Time SANTA CRUZ, Calif. – Over the past 60 years, marine biologists at UC Santa Cruz have monitored the behavior of northern elephant seals that journey to nearby Año Nuevo Natural Reserve. With the seals gathering on the beach by the thousands to breed and molt, generations of researchers have been able to amass more than 350,000 observations on over 50,000 seals. With the help of powerful technologies and the intrepidness to get close ...

Dessert stomach emerges in the brain

2025-02-13

To find the cause of the "dessert stomach", the researchers investigated the reaction of mice to sugar and found that completely satiated mice still ate desserts. Investigations of the brain showed that a group of nerve cells, the so-called POMC neurones, are responsible for this. These neurones become active as soon as the mice were given access to sugar which facilitated their appetite. When mice are full and eat sugar, these nerve cells not only release signaling molecues that stimulate satiety, but also one of the body's own opiate: ß-endorphin. This acts on other nerve cells with opiate receptors and triggers a feeling of reward, ...

Fungus ‘hacks’ natural immune system causing neurodegeneration in fruit flies

2025-02-13

A fungal infection has been shown to trigger a fruit fly’s own immune system to destroy brain cells leading to signs of neurodegeneration, a new study has found. The paper published in PLOS Biology today found that a fungus called Beauveria bassiana was able to make the fly’s innate immune system trigger a process that kills neurons and glia in the brain, leading to more than half of flies dying after seven days compared to half of control samples living for nearly 50 days. In experiments conducted by a team of academics from the University of ...

A new view on 300 million years of brain evolution

2025-02-13

Leuven, 14 February 2025 – In a new study published in Science, a Belgian research team explores how genetic switches controlling gene activity define brain cell types across species. They trained deep learning models on human, mouse, and chicken brain data and found that while some cell types are highly conserved between birds and mammals after millions of years of evolution, others have evolved differently. The findings not only shed new light on brain evolution; they also provide powerful tools for studying how gene regulation shapes different cell types, across species or different disease states. Our brain, and by extension ...

Birds have developed complex brains independently from mammals

2025-02-13

The pallium is the brain region where the neocortex forms in mammals, the part responsible for cognitive and complex functions that most distinguishes humans from other species. The pallium has traditionally been considered a comparable structure among mammals, birds, and reptiles, varying only in complexity levels. It was assumed that this region housed similar neuronal types, with equivalent circuits for sensory and cognitive processing. Previous studies had identified the presence of shared excitatory and inhibitory neurons, as well as general connectivity patterns suggesting a similar evolutionary path in these ...

Protected habitats aren’t enough to save endangered mammals, MSU researchers find

2025-02-13

Images EAST LANSING, Mich. – Tropical forests are massive biodiversity storehouses. While these rich swathes of land constitute less than one-tenth of Earth’s surface, they harbor more than 60% of known species. Among them is a higher concentration of endangered species than anywhere else on Earth. However, these regions are also under immense pressure, as tropical land is rapidly being transformed for industrial and agricultural purposes. Worldwide, regional governments and international groups are establishing new protected areas to slow further loss of threatened species. However, new research appearing in the journal PLOS Biology demonstrates ...

U.S. stream network is longer during annual high-flow conditions

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: