Tag Archives: rivers

Amazon Rainforest Faces Drought as Deforestation Disrupts Atmospheric Rivers

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Deforestation in the Amazon

Vast areas of the Amazon rainforest are cleared for cattle ranching

Michael Dantas/AFP via Getty Images

The alarming rate of deforestation is significantly diminishing rainfall patterns across the Amazon, indicating that this vital rainforest could hit a catastrophic tipping point sooner than previously anticipated.

Research from 1980 to 2019 indicates that rainfall in the southern Amazon basin has diminished by 8 to 11 percent, based on satellite data and rain gauge readings. During this same time frame, tree cover in the region has shrunk by 16 percent, primarily due to deforestation linked to beef cattle ranching.

Contrastingly, deforestation has been less pronounced in the northern Amazon Basin, where precipitation has only shown minor increases that lack statistical significance.

Recent research highlights that deforestation contributes to arid conditions within a 300-kilometer radius. This new analysis reveals that this effect spans over a basin wider than 3,000 kilometers, suggesting that deforestation harms not just forests, but also the productivity of adjacent ranches and soybean farms, according to Dominique Spracklen from the University of Leeds.

“Some in agribusiness may perceive sections of the forest as underutilized land. Yet, these forests play a crucial role in maintaining regional rainfall, which in turn benefits our agricultural practices,” Spracklen explains.

Global warming is exacerbating the drying of the Amazon, culminating in extreme droughts and unprecedented wildfires in 2024. However, atmospheric studies led by Spracklen and colleagues indicate that deforestation is responsible for 52 to 75 percent of the decline in rainfall.

Moisture from the Atlantic Ocean is transported by prevailing winds into the Amazon, where it precipitates as rain. Plants contribute to this cycle as evaporation and transpiration return about three-quarters of that water to the atmosphere. Further downwind, it falls again as rain through multiple cycles, creating “flying rivers” that distribute moisture across the rainforest.

When forested areas are destroyed, over half of the rainwater is redirected to rivers and subsequently returns to the ocean, depleting the moisture available for the flying rivers and leading to reduced rainfall. Additionally, this diminishes atmospheric instability necessary for storm cloud formation, Spracklen and his team discovered.

As fewer trees slow down the wind, it tends to pick up speed, removing more moisture from the area.

Unlike previous research, this study employs a combination of data and modeling to effectively illustrate how deforestation impacts rainfall patterns, asserts Yadvinder Malhi from Oxford University.

“The atmosphere becomes smoother and, in a sense, slipperier. There’s reduced friction with the ground, enabling moisture to travel further out of forested regions,” Malhi notes, emphasizing the significance of secondary atmospheric processes often overlooked in prior studies.

Scientists voice concerns that the cumulative impact of heightened temperatures, drought, and deforestation could push the Amazon rainforest to a tipping point where it transitions into a savannah ecosystem, although the timeline for this transition remains uncertain. Spracklen and his colleagues found that climate models may underestimate the influence of deforestation on rainfall by as much as 50 percent, implying that the rainforest could face significant threats earlier than anticipated.

According to a 2022 study, there is a 37% probability that certain regions of the Amazon could vanish by 2100 if global temperatures, currently at 1.4°C, rise to 1.5°C. However, this does not necessarily imply that rainforests will convert into savannahs; it may lead to the emergence of fewer species and scrub forests capable of storing less carbon.

“The Amazon’s sensitivity is greater than we previously imagined, which is troubling,” he states. “We may be closer to the deforestation threshold than we realize, although there remains significant uncertainty surrounding this issue.”

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Source: www.newscientist.com

As Atmospheric Rivers Persist, Washington’s Infrastructure Faces Collapse.

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Numerous levees have collapsed, over a dozen highways have been shut down, and one fatality has been reported in Washington state as an atmospheric river storm continues to hammer the area, putting its infrastructure to the test.

Although the state’s dams and levees managed to withstand the initial wave of last week’s storms, the ongoing rainfall is beginning to overwhelm some levees.

Additionally, various low-lying areas in Western Washington remain inundated with slowly subsiding floodwaters.

During a news conference on Tuesday, Governor Bob Ferguson reported that there have been over 1,200 rescues across 10 counties since December 8. Thirteen state highways remain closed, and Highway 2, a key route across the Cascades, may remain shut for months. Interstate 90, the largest highway in the state, is also blocked due to a significant landslide.

“Our infrastructure is under significant strain,” Ferguson stated. “It has been compromised.”

Flooding occurred on Francis Road in Skagit County, Washington on Friday.
Evan Bush/NBC News

A 33-year-old man lost his life early Tuesday in Snohomish County, north of Seattle, when his car veered off into a ditch on a submerged rural farm road.

“We believe this marks the first fatality linked to this storm,” Ferguson commented, noting it was somewhat miraculous that there haven’t been additional casualties.

Courtney O’Keefe, public information director for the Snohomish County Sheriff’s Office, stated that the man was driving a Chevrolet Tahoe that drove through a traffic stop as his car began to flood. He called a friend, prompting them to contact 911 for help.

“There’s a ditch right next to the road. During flooding, it’s challenging to determine where the road ends and the ditch starts,” O’Keefe noted, mentioning that the tragic accident is still being investigated.

In the last two days, two levees have failed in the suburbs of Seattle.

The latest incident occurred Tuesday morning in the town of Pacific, close to the White River.

“A leak as wide as a fire hose was detected last night around 12:30,” informed Sheri Badger, a spokeswoman for the King County Emergency Management Agency. “It has since increased to approximately 120 feet in length.”

The semi-permanent embankment was built with HESCO Barrier, a mesh and fabric structure filled with sand, earth, and gravel. Badger explained that barriers were stacked atop one another, with water seeping through the gaps.

An evacuation advisory has been issued for 1,300 residents in the area. Crews are actively adding sandbags and “super sacks” to reinforce the breach.

On Monday, a six-foot section of another levee gave way in Tukwila, a locality on the Green River south of Seattle. King County ordered an evacuation for around 1,100 individuals, but crews managed to promptly repair the breach, limiting the damage.

The embankment had been previously damaged by flooding about four years ago and remained partially unrehabilitated.

At least two dams are currently being monitored for cracks or potential failures, according to the state Department of Ecology. One such dam is Lake Sylvia Dam, which is classified as “poor condition” with “significant” risks as per the National Inventory of Dams, with the last inspection conducted in November 2024. It was built in 1918.

Spokesman Andrew Weinke indicated that several roads could be at risk in the event of a dam failure, but there would be no immediate repercussions for homes or residents.

Much of western Washington is traversed by rivers that flow steeply from the Cascade Mountains. These rivers, which drain into Puget Sound, historically meandered across wide floodplains, forming a complex network. However, over a century ago, much of it was dammed and straightened for potable water, flood control, and hydroelectric energy generation. As a result, streams evolved into channelized rivers, akin to superhighways for water flow.

Since that time, levee systems have been reinforced to contain the water, with homes and industrial buildings often constructed near the floodplain’s edges.

Certain areas that have experienced severe flooding previously are likely to be inundated again.

On Monday, a house was surrounded by floodwaters in Sumas.
Brandon Bell/Getty Images

Atmospheric rivers, such as the recent storm systems, appear like fire hoses on weather radar.

These storms are often referred to as the “Pineapple Express” as they can carry humidity and warmth from Pacific waters near Hawaii and other tropical regions.

The Pacific Northwest typically handles one or two of these storms without significant impact; however, three heavy rain events have occurred since December 8. Some parts of the North and Central Cascades received up to 16 inches of rain within three days, making them the steepest and most rugged mountains in the continental United States.

“The atmospheric river phenomenon was considerable, but not unprecedented,” stated state climatologist Guillaume Mauger. “What stands out is the consecutive nature of these storms.”

Members of a Sumas household were working on Monday to repair their homes, which were flooded during last week’s heavy rains.
Brandon Bell/Getty Images

He noted that more intense river flooding is anticipated in the future as rising temperatures will lead to increased rainfall rather than snowfall. As the climate warms, rainfall also tends to become more intense.

One study predicts flooding along the Skagit River by the end of this century, with potential volumes increasing by nearly 50% every 100 years by the 2080s. Given that the river already has dams, existing flood control measures are deemed “mostly ineffective,” the study found.

Mauger suggested that the best approach to mitigate future risks is to provide rivers with more space.

As more storms are on the horizon, dam operators are compelled to redirect water to upstream reservoirs to avert potential flooding.

John Taylor, Director of King County Natural Resources and Parks, mentioned that officials are closely monitoring several levees of concern and reinforcing those known to be weak.

“We’ve noticed that levees, which typically perform well during floods, are starting to fail due to saturation and significant pressure,” he explained.

The Skagit and Snoqualmie rivers are expected to reach or surpass major flood stage by Thursday morning.

Source: www.nbcnews.com

U.S. Rivers Face Unprecedented and Severe Impacts from Global Warming

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Rivers across the United States are experiencing increasing temperatures.

A recent analysis of nearly 1,500 river locations spanning over 40 years reveals a rise in the frequency, intensity, and duration of heat waves, posing risks to many species accustomed to cooler waters.

“The increase in river heat waves is actually outpacing that of air heat waves, which is quite surprising,” states Li Li, a professor of environmental engineering at Pennsylvania State University and the study’s author.

A new analysis published in the peer-reviewed journal Proceedings of the National Academy of Sciences is the first comprehensive study defining river heat waves as five consecutive hot days compared to seasonal averages.

The researchers identified climate change, which significantly impacts humans, as a major contributor to this trend, due to diminishing snowpacks and slower stream flows.

Human factors also play a role; for example, dams inhibit downstream flow, while urban structures absorb heat, warming both air and water.

Scientists are concerned that species reliant on cold water, such as salmon and trout, will increasingly struggle as river temperatures rise. Li emphasizes the necessity of tracking fish fatalities and ongoing trends.

Higher temperatures decrease the amount of dissolved oxygen in water. Additionally, cold water species generally exhibit increased metabolism in warmer conditions, leading to further oxygen depletion.

These findings could influence basin management strategies and help determine if adjustments in irrigation or dam releases can support aquatic life during elevated temperatures.

“Water management practices can significantly impact heat waves,” noted Jonathan Walter, a research scientist at UC Davis’ Center for Watershed Sciences, who was not part of the study. “If there is sufficient reservoir water, it may be feasible to moderate downstream temperatures by releasing water to mitigate extreme heat.”

While heat waves in oceans and lakes have been studied extensively, there has been limited research on the implications of rising temperatures in rivers until now.

Satellite data have advanced the study of ocean and lake heat, but river temperature research is challenged by reliance on often unusable river gauge sensors, resulting in significant data gaps.

For this new study, researchers analyzed data from 1,471 US Geological Survey monitoring sites from 1980 to 2022.

This data enabled an assessment of shifts in streams nationwide, revealing that by 2022, river heat waves were occurring more frequently than in 1980, with an average increase of 1.8 additional heatwave events per year. These heat waves were also more severe, with temperatures during these events being approximately 0.8 degrees Fahrenheit higher in 2022 than in 1980. Moreover, the duration of heat wave events extended by over three days.

Li noted that this extra heat caused an average of about 12 days of heat stress for cold water species. The study defined 59°F as the threshold for heat stress, as many species, including bull trout, face survival challenges at this temperature.

“When considering water, its visibility draws attention to its significance,” Li remarked. “We hope this research raises public awareness on water quality challenges stemming from climate change.”

Source: www.nbcnews.com

Archaeologists Discover That Rivers and Tides Fueled the Rise of Ancient Schmer

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The latest study presents paleoenvironmental models indicating how tidal dynamics played a crucial role in the early evolution of Sumerian agriculture and sociopolitical intricacies.

Cylinder seal impression from the Uruk era circa 3100 BC. Image credit: Louvre Museum.

The earliest known network of city-states, intricately linked by common cultural practices and economic ties, emerged in southern Mesopotamia approximately 5,000 years ago.

The prosperity of this urban center, collectively referred to as Schmer, was fundamentally based on agriculture, supported by extensive irrigation systems.

The urbanization of Schmah, following the long-standing rural Ubaid culture, was part of a process that began at least prior to the millennium during the Uruk period (6,000-5,200 years ago).

The concurrent rise in population, innovation, and professional specialization during this time led to the formation of a state system with a complex economy, interlinking urban centers with their rural surroundings.

This “Sumerian takeoff” could not have happened in the challenging, arid tropical region between the Arabian and Iranian deserts without access to the perennial freshwater provided by the Euphrates and Tigris rivers.

However, questions remain about how, and when, labor-intensive large-scale irrigation became prevalent in the area, and how the abundance of water transformed into social prosperity.

“Our findings indicate that Sumer was literally built upon the rhythm of water, culturally,” states Dr. Lviv Giosan, a researcher at Woods Hole Marine Facilities.

“The cyclical tidal patterns and the morphodynamics of deltas—how landscapes evolve over time due to dynamic processes—were intricately woven into Sumerian mythology, innovation, and daily life.”

This research reveals that between 7,000 to 5,000 years ago, the Persian Gulf was expanding inland, with tides pushing freshwater into the lower Tigris and Euphrates twice daily.

Scholars propose that early communities harnessed this reliable hydrology through short canals to irrigate crops and cultivate dates, allowing for high-yield farming without the need for vast infrastructure.

As the river created a delta at the bay’s head, tidal access to the interior was obstructed.

The subsequent loss of tidal influence may have sparked ecological and economic crises, necessitating a significant social response.

The extensive efforts for irrigation and flood management that followed ultimately characterized Schmer’s golden age.

Dr. Reed Goodman, a researcher at Clemson University, remarked:

“The Mesopotamian delta was distinct. Its constantly shifting land spurred some of the earliest intensive agriculture in history and led to ambitious social experiments, driven by that restless land.”

In addition to environmental factors, this study also investigates the cultural impact of this aquatic foundation, linking Mesopotamia to the Sumerian pantheon’s flood myth.

“The key conclusions of this research highlight what we discovered in Ragash,” notes Dr. Holly Pittman, director of the Ragash Archaeology Project at the Penn Museum.

“Rapid environmental changes fueled inequality, political integration, and the ideology of the world’s first urban societies.”

Leveraging ancient environmental and landscape data, new samples from historic Ragash archaeological sites, and detailed satellite imagery, the authors reconstructed what Sumerian coasts may have looked like long ago and envisioned how its inhabitants adapted to their ever-changing environment.

“Our work underscores both the opportunities and risks associated with social transformation in response to significant environmental crises,” Dr. Giosan added.

“It is always fascinating to uncover genuine history hidden within mythology, and interdisciplinary research like ours plays a crucial role in revealing it.”

study Published online in the journal PLOS 1.

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L. Giosan & R. Goodman. 2025. The morpho-mechanical foundations of Sumerian civilization. PLOS 1 20(8): E0329084; doi: 10.1371/journal.pone.0329084

Source: www.sci.news

New research shows that several Titan rivers do not flow into a delta

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The Earth’s coastline is an attractive place where liquids are mixed and materials are shaped into clear terrain, such as the River Delta. Similar active coastlines exist in Titan, the moon of Saturn, where liquid hydrocarbons (methane and ethane) replace water. However, studies of Titan’s coastline, particularly the River Delta, are challenging due to the limited imaging data and the unknown nature of its materials. To overcome these challenges, Brown University planetary scientists, MIT, the MIT-Whoi joint program of oceanography, Woods Hole Marine Facilities, Cornell University, have developed a new model that simulates the Earth’s coastline as if it were found in NASA’s Cassini spacecraft. They discovered that they could detect large terrain in Titan with the correct contrast. They then returned to Titan and remap the coastline. Surprisingly, they discovered that unlike on Earth, where many large rivers house the delta of rivers, many of the Titan rivers do not end in the delta. They also discovered submerged features of Titan on the seabed, suggesting changes in sea level and active currents below sea level.

This composite image shows an infrared view of Titan. In this image, blue represents the wavelength centered at 1.3 microns, green represents 2.0 microns, and red represents 5.0 microns. Views at visible wavelengths show only the hazy atmosphere of Titan. The near-infrared wavelength of this image allows Cassini’s vision to penetrate the haze and reveal the surface of the moon. The view focuses primarily on the terrain in the hemisphere facing Saturn in Titan. Image credit: NASA/JPL-Caltech/Space Science Institute.

“We’ve seen a lot of effort into this world,” said Dr. Sam Burch, a researcher at Brown University.

“But the absence of delta raises many new questions.”

“We take it for granted that we get a delta if we have rivers and sediments.”

“But Titan is odd. It’s a playground for studying the processes we thought we understood.”

Titan is the largest of Saturn’s 274 confirmed moons. Its thick nitrogen and methane atmosphere creates many earth-like climate and weather features.

Titan has clouds, wind, rain, rivers, lakes and oceans. However, instead of water, Titan’s liquids contain methane and ethane. Methane is a liquid at Titan’s chilly surface temperatures.

Scientists learned about Titan’s liquid body when Cassini’s spaceship flew in 2006. Peering into the thick atmosphere of Titan with Cassini’s synthetic aperture radar (SAR), the spacecraft revealed a large body of liquid and a large flat area with a large flat area.

However, what is largely missing from Cassini’s SAR images was the delta, even at the mouth of the large river.

However, it was not clear whether Delta was really absent or not shown in Cassini’s SAR data.

That is a question Dr. Burch and his colleagues tried to answer in their new research.

The problem with Cassini’s SAR data is that shallow liquid methane is largely transparent in every image.

Therefore, while images of the SAR allowed us to see wide ocean and river channels, it is difficult to create coastal features with confidence, as it is difficult to see where the coast ends and where the seabed begins.

For this study, the authors developed a numerical model to simulate what Cassini’s SAR sees whether they are viewing a landscape that scientists understand well: Earth.

In the model, Earth’s rivers and ocean waters were replaced by Titan methane liquids with different radar absorption properties compared to water.

“We basically created a synthetic SAR image of the Earth that assumes the properties of Titan’s liquids instead of the Earth,” Dr. Burch said.

“If you see the SAR images of the landscape, we know so well that we can go back to Titan and get a little better at what we’re looking at.”

Researchers have found that synthetic SAR images of the Earth clearly solved large deltas and many other large coastal landscapes.

“If you have the size of a delta at the mouth of the Mississippi River, you should be able to see it,” Dr. Burch said.

“If we have a big barrier island or similar coastal landscape that we see along the US Gulf Coast, we should be able to see them.”

But as scientists shook the Titan images in light of new analysis, they were almost empty.

The rest of the moon’s river was completely delta free, except for two possible deltas near Titan’s Antarctic.

They found that only about 1.3% of the large rivers of Titan that end on the coastline have the delta. In contrast, on Earth, almost every river of similar size has a delta.

“It’s not entirely clear why Titans generally lack delta,” Dr. Burch said.

“The fluid properties of the Titan river should allow sediment to be carried and deposited.”

“Because the sea level in Titan is rising so rapidly, the delta can crush the landscape faster than it accumulates in a single location.”

“The winds and currents along the Titan coast can also play a similarly large role in preventing delta formation.”

And the only delta of mystery posed by new research is not missing.

A new analysis of Cassini SAR data on the Titan coast reveals holes of unknown origin deep within the lake and ocean.

Researchers also found deep waterways on the ocean floor, which appear to have been carved by the river flow, but it is not clear how they got there.

“All of these surprises require more research to fully understand,” Dr. Burch said.

“This is not really what we expected. But Titan does this well for us, and I think it’s an attractive place to study.”

study It was published in Journal of Journal Geophysics: Planets.

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SPD Birch et al. 2025. Detectability of coastal topography on Titan using Cassini radar. jgr planet 130 (3): e2024je008737; doi: 10.1029/2024je008737

Source: www.sci.news

Study suggests that nearby rivers are causing Mount Everest’s peak to rise

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Mount Everest, also known as Chomolangma in Tibetan and Sagarmatha in Nepali, is about 15 to 50 meters higher than its original height due to uplift caused by erosion of nearby river canyons, and therefore continues to grow. This is revealed in a new study.

Han et al. They found that erosion from a network of rivers about 75 km from Everest had carved out a significant canyon. This landmass loss has caused mountains to rise by 2 mm per year, and their heights have already increased by 15 to 50 meters over the past 89,000 years. Image credit: truthseeker08.

The Himalayas, formed by the subduction of the Indian tectonic plate beneath the Eurasian plate, are home to some of the highest mountains on Earth.

Mount Everest is 8,849 meters above sea level, about 250 meters higher than the other highest peaks in the Himalayas.

Previous analysis of GPS data suggests that Everest's recent uplift is about 2 mm per year, which exceeds the expected uplift rate for the mountain range and suggests that mechanisms other than ongoing regional tectonics are responsible. This suggests that it may contribute to this process.

“Mount Everest is a remarkable mountain of myth and legend, and it continues to grow,” said Dr. Student Adam Smith.

“Our research shows that the nearby river system is cutting deeper and the loss of material is causing the mountain to spring further upwards.”

In this study, Smith and his colleagues investigated whether changes in rivers near the mountain may have contributed to Everest's recent uplift.

They used a numerical model to simulate the evolution of the Kosi river network and compared it to existing landforms.

These models suggest that the Arun River, a major tributary of the Kosi River, was involved in the occupation of another river 89,000 years ago.

The diversion of river water accelerated river erosion as the river adapted to its new path, resulting in the formation of the deep Arun River Gorge.

“Currently, the Arun River flows east of Mount Everest and joins the larger Kosi River system downstream,” Mr Smith said.

“For thousands of years, the River Arun has carved great gorges along its banks, washing away billions of tonnes of soil and sediment.”

“There are interesting river systems in the Everest region,” said Dr. Jing Geng Dai, a researcher at the China University of Geosciences.

“The upper Arun River flows eastward through highlands with flat valleys.''

“Then it suddenly turns south as the Kosi River, dropping in elevation and becoming steeper.”

“This unique feature of instability may be related to Everest's extreme height.”

The authors conclude that although erosion would have lowered local elevations along the river channel, the formation of the canyon removed the eroded mass relatively abruptly, allowing the surrounding landforms, including Everest, to compensate with surface uplift. It is argued that there is a possibility that

Although its contribution may be small compared to tectonic deformation, fluvial capture may play a role in both erosion and uplift of high landforms.

“Everest and its neighboring mountains are growing because isotropic rebound is causing them to rise faster than erosional wear,” said Dr. Matthew Fox, a researcher at University College London. said.

“Using GPS equipment, we can see it grow by about two millimeters every year. Now we can better understand what's causing that.”

“The change in the height of Mount Everest really highlights the dynamic nature of the Earth's surface,” says Dr. Xu Han, a researcher at the China University of Geosciences.

“The interaction between the erosion of the Arun River and the upward pressure of the Earth's mantle gives Everest a boost, pushing it higher than normal.”

of study Published in a magazine natural earth science.

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X Han others. The recent uplift of Chomolungma was reinforced by river drainage piracy. nut. earth sciencepublished online on September 30, 2024. doi: 10.1038/s41561-024-01535-w

Source: www.sci.news

Titan, Saturn’s moon, boasts both freshwater rivers and saltwater oceans

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Titan’s north polar region, imaged using Cassini’s radar signature, shows blue hydrocarbon oceans.

NASA / JPL-Caltech / Italian Space Agency / USGS

The most detailed look yet at Saturn’s moon Titan’s strange lakes has revealed a diverse marine landscape similar to Earth’s, with a mix of freshwater rivers and saltwater oceans.

Unlike Earth’s watery oceans, Titan’s lakes are composed of methane and ethane, which are liquid at the planet’s average surface temperature, about −179 °C (−290 °F).

Radar measurements from NASA’s Cassini spacecraft, which orbited Saturn from 2004 to 2017, suggested differences in the lakes’ properties, including their composition and surface waves, but the signals didn’t contain enough information to distinguish between them.

now, Valerio Poggiali Poggiali and his colleagues at Cornell University in New York used a different radar technique to map the composition and surface of Titan’s oceans, revealing that the amount of ethane increases as you move south across the planet from the north pole. “The further north you go, the cleaner and purer the oceans become. They’re dominated by methane,” Poggiali says.

Previous radar measurements were made using signals sent and received at the same location on the Cassini spacecraft, which meant the reflected radio waves were polarized in one direction, or twisted.

The new study analyzed signals from Cassini’s radar that were reflected off the lake’s surface and picked up by NASA’s Deep Space Network, a radio antenna on Earth. The shallow angle of the reflected signal meant it contained two different polarized waves, giving Poggiali and his colleagues more information about the lake’s properties.

They found that many of the rivers and estuaries that feed the lake have rough surfaces caused by wind-driven waves, which could be a sign of active tides and currents feeding into the lake, Poggiali said. “Surface activity is very important if we want to plan future missions like a Titan submarine, but also to better understand Titan’s environment in terms of wind and atmospheric properties.”

Poggiali and his colleagues also found that the methane content was higher before the river flowed into the lake, which could help trace the methane and ethane cycle on Titan, Poggiali says. Ingo Muller-Wodarg “On Earth, when rivers flow into large, salty oceans, we find that the water becomes less saline near where the river flows in,” say researchers from Imperial College London. “Something similar is happening here, but it’s not the salinity that’s the problem, it’s the relative proportions of methane and ethane.”

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Source: www.newscientist.com

A New Study Estimates the Volume of Water Flowing Through Earth’s Rivers

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Accurate assessments of global river flows and water storage are important to inform water management practices, but current estimates of global river flows represent a significant spread, and river storage Estimates remain sparse. Estimates of river flow and water storage are hampered by uncertainty in land runoff, an unobserved quantity that provides water withdrawal to rivers. In a new study, geoscientists at NASA's Jet Propulsion Laboratory and elsewhere leverage an ensemble of global streamflow observations and land surface models to create a globally gauge-corrected monthly streamflow and storage dataset. Generating. They estimate the average global river storage capacity to be 2,246 km .3 (This is equivalent to half of the water in Lake Michigan, about 0.006% of all fresh water, which itself is equivalent to 2.5% of the Earth's volume) and 37,411 km of the world's continental streams.3 per year.

collins other. Estimates flows through 3 million river segments characterized by intense human water use, including the Colorado River, Amazon River, Orange River, and parts of the Murray-Darling River basin (shown here in gray) identified locations around the world. Image credit: NASA.

Rivers are considered the most renewable, most accessible, and therefore most sustainable sources of fresh water.

Therefore, several studies have attempted to quantify the world's river waters.

However, surprisingly little is known about the average and temporal variation in global river water storage, and even more so, about the temporal variation in global river discharge.

“Over the years, researchers have made numerous estimates of how much water flows from rivers to the ocean, but estimates of how much water rivers collectively hold (known as water storage) “There are fewer and more uncertainties,” said Dr. Cedric David. A researcher at NASA's Jet Propulsion Laboratory.

“We don't know how much water we have in our accounts. Population growth and climate change are further complicating the problem.”

“There are many things we can do to manage our water usage and ensure there is enough water for everyone, but the first question is: How much water do we have? It's the basis of everything else. is.”

In this study, Dr. David and colleagues used a new methodology that combines flow meter measurements with computer models of about 3 million river segments around the world.

They identified the Amazon Basin as the region with the most river water storage, with approximately 850 km of water storage.3 Water amount – approximately 38% of global estimates.

The same basin discharges the most water into the ocean: 6,789 km3 per year. This corresponds to 18% of the emissions into the world's oceans, which average 37,411 km.3 Years from 1980 to 2009.

Although it is impossible for a river to have a negative flow rate, the study's computational approach does not take into account upstream flows, but it is possible that some river segments receive less water than they enter. It may leak.

Researchers found similar findings in parts of the Colorado, Amazon, and Orange river basins, as well as the Murray-Darling basin in southeastern Australia. These negative flows mainly indicate heavy water use by humans.

“These are places where we see evidence of water management,” says Dr. Elissa Collins, a researcher at the University of North Carolina at Chapel Hill.

of study Published in a magazine natural earth science.

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Elle Collins other. Global patterns of river water storage dependent on residence time. nut.earth science, published online March 15, 2024. doi: 10.1038/s41561-024-01421-5

Source: www.sci.news

California’s atmospheric rivers pose higher landslide risk

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Recent rains have accelerated land movement in the landslide-prone coastal city of Rancho Palos Verdes in Los Angeles County, altering previously uncharted landslide areas, as stated in a city news release.

The sedimentary rock layers in the area tilt toward the sea, causing clay layers to expand and become slippery when saturated with water due to minimal friction, explained Onderdonk.

Concerning areas are expanding due to heavy rains, with a decades-old plan to dewater slopes in the Avalon Cove landslide area significantly slowing down movement, but recent acceleration led to the closure of Wayfarer’s Chapel, designed by Frank Lloyd Wright Jr. in Avalon Cove.

The city of Rancho Palos Verdes, faced with risks to homes and roads, is urging Gov. Gavin Newsom to proceed with state and federal emergency declarations for expedited emergency fixes through the permitting process, as mentioned here.

Many coastal cities in California are vulnerable to landslides.

A tarp covers the bluff behind the house overlooking Capistrano Beach in Dana Point, California. Several seaside areas are dealing with concerns of landslides and coastal erosion following recent storms that hit the state.
NBC News

Drone footage of beach houses built on a landslide rubble in Dana Point made headlines recently. Scientists are studying how climate change affects landslides, expected to be detailed in a 2022 study in “Geophysical Research Letters.”

Research indicates that atmospheric river storms in the San Francisco Bay Area coincide with landslides about 76% of the time and are becoming more frequent and intense on the West Coast due to a warming atmosphere’s increased water vapor absorption and transport capacity.

A warming sea due to human-induced global warming is leading to rising sea levels, endangering California’s coastlines, with projections suggesting significant beach loss by 2100.

Edward and Debbie Winston-Levin, residents of Dana Point, express concerns about coastal erosion impacting their property and affecting nearby amenities.

After recent storms in California, Edwards, who lives in Dana Point, looks out at his waterfront home amid concerns about landslides and coastal erosion.
NBC News

Various coastal cities are making adaptations due to the changing landscape, with plans in motion to address potential risks and impacts.

Experts caution that protecting California’s iconic beaches while safeguarding cliffside homes poses a challenging dilemma for communities.

Source: www.nbcnews.com

The World’s Top 10 Longest Rivers of 2023

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The largest civilizations have been built on and around it, providing a precious source of water and life. Of course, we are talking about rivers. There are many impressively long rivers around the world, but what is the world’s longest river?

Determining the exact length of a river is a complex process. You need to know the source location and the estuary location, that is, where the river starts and ends, respectively.

This is more difficult than it sounds and can change over time. Considering tributaries and waterways can further complicate matters, along with the changing seasons through which the river passes.

For this reason, river length is not an exact science and this is why you see a list of different lengths on the web. That also means there’s a debate about the longest river on Earth (more on that below). The lengths listed below are approximations that take into account a range of variables.

With all this in mind, here are the top 10 longest rivers in the world.

10. Amur River – 4,444km (2,761 miles)

Photo credit: Getty

The tenth longest river in the world is the Amur River, with a total length of 4,444 km (2,761 miles). This is its total length including its most distant source, the Argun River.

The Amur River’s flow begins in Mongolia and heads east through China and Russia, forming the main border between the Russian Far East and northeast China. Its mouth is the Amur Estuary, which flows into the Tartary Strait.

The kaluga fish, which can grow up to 5.6 meters long, lives here and is just one of the 100 species of fish found in this basin.You can also find indian lotus flower The northernmost habitat along the river.

9. Congo River – 4,700km (2,920 miles)

The Congo River is the ninth longest river in the world and the second longest in Africa, with a total distance of 4,700 km (2,922 miles) from its furthest source to its mouth.

Traveling through the Democratic Republic of Congo, Central African Republic, Angola, Republic of Congo, Tanzania, Cameroon, Zambia, Burundi, and Rwanda. It begins in the east, arcs to the northwest, and then flows southwest, emptying into the Atlantic Ocean at its mouth on the borders of Angola aand the Democratic Republic of the Congo.

This river, which flows through the Congo rainforest, is the second strongest current in the world after the Amazon. It provides an important water source for more than 400 species of mammals, including gorillas, African elephants, and bonobos, as well as more than 1,700 species of birds and fish.

8. Rio de la Plata – 4,880km (3,032 miles)

The Rio de la Plata is the eighth longest river in the world, with a length of 4,880 km (3,032 miles). This is the combined length of the overlapping rivers Paraná, Rio Grande, and Uruguay.

The Plata River itself is only 290 km (180 miles) long, but its tributaries are even longer, running from north to south through Brazil, Bolivia, Paraguay, Uruguay, and Argentina. It empties into the Atlantic Ocean between Argentina and Uruguay.

Another accolade of the Rio de la Plata is that it is the widest river in the world. In some areas its width is up to 220 km.

7. Ob River – 5,410km (3,362 miles)

Photo credit: Getty

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Source: www.sciencefocus.com

Rivers’ Inability to Preserve Coastal Wetlands: A Problematic Situation

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Salt marshes in Barnstable, Massachusetts show signs of erosion and submergence as sea levels rise (December 2, 2022).Credit: Erin Peck

Creating wetlands, which are being submerged by rising sea levels, remains a challenge, but scientists are now one step closer to identifying a solution.

Amid climate change, large-scale dam removal projects are gaining traction as a solution to the loss of coastal wetlands that reduce flooding, filter water, and provide habitat for wildlife. However, in a recently published paper, scienceresearchers concluded that this strategy does not work in most rivers in the United States.

Limited sediment supply hinders wetland recovery

The reason is that there is not enough sediment. Of the nearly 5,000 rivers analyzed, nearly three out of four were unable to transport enough sediment to keep up with sea level rise in the coastal regions they connect to. Nearly half were at least 10 times short of the required amount of sediment.

This is the first national study to examine how much watershed sediment can be deposited in coastal areas by rivers. So far, research has focused on a few very large rivers. mississippi,and, Elfa In Washington, they are not representative of most other areas of the continental United States.

Most watersheds in the United States are small and are not major sources of sediment buildup in wetlands, researchers said. It is on these small rivers that most dams are located.

Expert insights on dam removal and sediment supply

The study was led by Dr. Scott Ensign, a research scientist at the Stroud Water Research Center, a nonprofit organization that studies freshwater streams and rivers around the world. He said: “Elfa is the poster child for dam removal projects that restore coastal sediment, and for good reason: it liberated vast amounts of sediment and sand.

“However, rivers along the East and Gulf coasts are not as steep as the West Coast and there is less sediment that can reach the wetlands, so the wetlands are wider and require more sediment to keep them above the rising ocean.” is required.Basically, the numbers don’t add up.”

Dr. Christopher Craft, an Indiana University professor who focuses on wetland restoration and climate change, said, “The extensive and comprehensive spatial analysis conducted by the authors shows that sediment supply in most coastal basins is This strongly suggests that this is insufficient.” As sea levels rise, tidal wetlands appear. In other words, sediment cannot save them. ”

Methodology and findings

Ensign and her co-authors, Joanne Halls of the University of North Carolina Wilmington and Erin Peck of the University of Massachusetts, used publicly available data from the U.S. Geological Survey and the National Oceanic and Atmospheric Administration to map watersheds to coastal wetlands. Sediment supply was modeled. Uses Esri’s ArcGIS Pro technology. They then compared their projections to previously reported rates of change for tidal wetlands across the United States.

“By and large, the sediment that saves most wetlands from drowning doesn’t come from upstream rivers. In many places on the East Coast, removing dams won’t help. You’ll have to look elsewhere.” explained the lieutenant.

Impact on wetland conservation

Dr. James Pizzuto, a professor of geological sciences who specializes in river science at the University of Delaware, said the researchers deftly addressed a complex problem. “These results, and the local variations documented by mapping the entire U.S. coastline, provide important guidance to managers and scientists, and future efforts to investigate other processes beyond basin sediments. “We are documenting where we should focus our efforts,” he said.

Such efforts include finding ways to retain more mineral deposits, plant material and organic carbon in wetland soils, said Donald F. Boesch, professor emeritus at the University of Maryland Center for Environmental Science. He explained that it was possible. “This is true both where sediment is being depleted and where it is being diverted to construct and maintain wetlands with relatively high rates of sea level rise, such as the Mississippi Delta,” he said. ” he said.

Future research and conservation strategies

Future research is needed to measure how much sediment is trapped behind a particular dam and accurately predict the impact on downstream tidal wetlands.

“In general, the most important action to protect tidal wetlands is to allow them to move up slopes. In some areas, we need to restore natural hydrology and protect lowlands,” said Ensign. Direct application of deposits and other engineering approaches may also be helpful at very local scales.”

References: Scott H. Ensign, Joanne N. Halls, and Erin K. Peck, “Catchment Sediments Cannot Offset Sea Level Rise in Most U.S. Tidal Wetlands,” December 7, 2023. science.
DOI: 10.1126/science.adj0513

The National Science Foundation funded the research.

Source: scitechdaily.com