Articles tagged with Dams
A team of economists and fish ecologists found that modern fish passage facilities were unsuccessful in allowing economically important species such as salmon, shad, and river herring to pass through dams. The study highlights the need for dam removals to restore diadromous species populations.
A study by the University of Southampton found that beaver dams can have both negative and positive effects on fish populations. While beaver activities can temporarily impede fish movement and reduce spawning habitat, they also increase habitat diversity and abundance of invertebrates, benefiting fish.
Researchers at Washington State University found that dams and reservoirs emit significant amounts of methane, a potent greenhouse gas. The study's findings suggest that managing drawdowns could reduce methane emissions and may even make decommissioning reservoirs a net sink for carbon.
Researchers at the University of Cincinnati discovered a massive ancient dam built by the Maya, stretching over 260 feet and holding 20 million gallons of water. The dam, constructed from cut stone and earth, was part of a sophisticated water management system that allowed the city to thrive despite periodic droughts.
A worldwide survey found that all continents except Antarctica have regions where dam obstruction poses a significant threat to freshwater organisms. The study identified 18 ecoregions with notable numbers of fish species at risk, including the Murray-Darling Province in Australia and the South Atlantic coast of the United States.
The study found that 60% of planned dams would disrupt the free-flowing nature of many Andean-Amazon rivers, threatening the region's biodiversity. Nearly half of the proposed dams were classified as high impact, highlighting the urgent need for strategic planning and evaluation of new dams.
A new flood simulation tool, combined with the Dams Sector Analysis Tool, enables rapid visualization and training for emergency responders. The software can model catastrophic flooding in under 24 minutes, improving disaster management and preparedness.
The High Level Panel will discuss a 'nexus' approach to water management, planning projects with input from stakeholders in the food, water, and energy sectors. This approach aims to reduce conflicts between these sectors over dwindling water resources as global food and energy production intensify.
Researchers found evidence supporting the single-water-source hypothesis for Yellowstone's geysers, suggesting a common source of subsurface water. Additionally, gravity waves in the Martian mesosphere were linked to the formation of carbon dioxide clouds, which could impact global climate models.
Researchers have discovered evidence of a late Pleistocene landslide-dammed lake along California's Eel River, which formed around 22,500 years ago. The lake's existence explains the genetic similarity between two types of ocean-going steelhead trout found in the river today.
Scientists at University of Oregon and Caltech discovered a 22,500-year-old landslide dammed the upper reaches of the Eel River, forming a 30-mile-long lake that disappeared over time. The lake's presence may explain genetic similarity among steelhead trout found in the river today.
The University of Arizona College of Engineering has been awarded grants from the US Department of Defense to develop high-tech measuring equipment for real-world applications in chemical and civil engineering. Armin Sorooshian's project aims to study cloud droplets and their effect on precipitation, while Jennifer Duan's project focus...
Researchers found that a buried mangrove layer in the Caribbean dampens seismic waves, reducing liquefaction risk. A new active fault was also identified near Lake Tahoe using LiDAR technology, potentially threatening the area with a magnitude 6.4-6.9 earthquake.
A new, global database of large dams and reservoirs has been created to inform sustainable river-flow management. The Global Reservoir and Dam database (GRanD) contains information on 6,862 dams and their associated reservoirs, providing a holistic view of entire river basins.
The arch dam's performance is affected by the relaxation of its foundation following excavation. The study found that relaxation increases principal tensile stresses at the upstream face and compressive stress at the downstream face, which is undesirable for safety.
Research on Rana boylii reveals tadpoles are weak swimmers and don't survive high-flow events, while habitat modeling tools provide reliable predictions. The study's findings guide conservation planning for the species, emphasizing the importance of mimicking natural flow patterns to conserve riverine species.
A new report highlights the need for increased investment in diverse water storage options to reduce uncertainty and improve production of rainfed farming. The study argues against overreliance on single solutions like big dams, proposing an integrated approach that combines large- and small-scale storage options.
Research suggests that maternal signals associated with overweight mothers can permanently alter a child's ability to regulate their weight. Studies found that offspring of overweight dams gained more weight and fat mass when given unlimited high-fat rations, indicating increased susceptibility to obesity.
A new acoustic telemetry system, JSATS, detects 98% of tagged fish in juvenile salmon migration studies, allowing for more precise survival estimates and reducing the number of fish needed. The system's smaller tag size and flexible receiver placement capabilities also improve conservation efforts.
Intersex fish were found in about a third of all sites examined from the Apalachicola, Colorado, Columbia, Mobile, Mississippi, Pee Dee, Rio Grande, Savannah, and Yukon River basins. Largemouth bass in southeastern U.S. had the highest prevalence of intersex, with some sites reporting up to 73% incidence.
The Pacific Northwest National Laboratory will lead a $6.8 million study to examine the environmental impacts of marine and hydrokinetic power. The project will investigate risks to wildlife and habitats, conduct laboratory and field experiments, and predict long-term effects.
Researchers at PNNL developed acoustic tags to measure salmon survival rates and a hydro model to direct fish away from predators. These technologies aid in improving salmon passage at Columbia Basin's hydroelectric dams.
Researchers at NC State University have found an exponentially better way to protect streams and lakes from the muddy runoff associated with stormwater around road and other construction projects. The alternative method uses natural fiber check dams enhanced with polyacrylamide, significantly reducing sediment loss and pollution.
Scientists have discovered that transporting juvenile salmon downstream can hinder their ability to migrate back to their breeding grounds as adults. The study found that transported juveniles had lower survivorship and were less likely to find their way home, due to being disoriented by the boat journey. This can reduce the genetic fi...
Scientists at UW-Madison examine the role of soil patterns in dam restoration, discovering superimposed patterns that chronicle the basin's history. The researchers found fundamental differences in nutrient levels and physical structure between sediments deposited over the dam's lifetime and buried soils.
A new study found that salmon smolts survive at similar rates of 70-80% in both the Columbia and Fraser rivers, with differences attributed to stressors such as dams, water temperature, and contaminants. The research used acoustic and transponder tags to track survival rates over a four-year period.
A new study challenged conventional notions about salmon survival, finding that juvenile salmon in two west coast rivers had similar survival rates despite the presence of extensive dam networks. The study used tagging and tracking technologies to track small juvenile Pacific salmon from freshwater to ocean destinations.
A recent study found that some endangered Pacific salmon stocks are surviving as well as or better in rivers with hydroelectric dams as in those without. Researchers used acoustic telemetry technology to track juvenile salmon migration and survival rates in the Fraser and Columbia Rivers, revealing a surprising similarity between damme...
The Three Gorges Dam's reservoir will create a new ecosystem with unprecedented fluctuating water levels. Experts propose using terraced ponds, wetlands, and fish net systems to make the most of this situation.
A study by the Wildlife Conservation Society found that beaver dams provide critical habitat for migratory songbirds in semi-arid regions of the West. The more dams built, the more abundant and diverse local songbirds become.
New research suggests that glacial dams formed at the mouths of tributaries helped prevent the Tsangpo River from carving into the Tibetan Plateau. These dams, made of moraines and debris, flattened the river's slope and reduced its ability to cut into the surrounding terrain.
Two studies found that removing dams in Maine increased property values by reducing a penalty for being near the dam site. The penalty has shrunk since dam removal, and it now affects properties further away from the dam more than those closer to the dam.
Hydroelectricity dams are decreasing Lake Victoria's level by at least two meters, threatening food security and fisheries in Uganda, Kenya, and Tanzania. The dams' overuse has led to papyrus wetland collapse, eutrophication, and algal blooms, with far-reaching consequences for the lake's ecosystem and local populations.
Researchers at Duke University warn that dams in California's Central Valley are harming spring-run Chinook salmon populations by blocking access to habitat and fragmenting these populations. The study suggests removing dams could help alleviate water shortages and aid fish species.
A leading expert challenges the theory that an Indonesian mud volcano was triggered by an earthquake. Professor Richard Davies of Durham University's Centre for Research into Earth Energy Systems says drilling operations are more likely to be responsible.
China's Three Gorges Dam, a massive hydroelectric power generator, is being constructed on the Yangtze River. NASA satellites have provided detailed views of the dam's construction and its impact on climate and environment.
A biology professor at Northern Arizona University is developing ways to help rivers rebound to their natural ecosystems after dams are removed. Her team has successfully restored Fossil Creek's ecosystem, serving as a national case study in dam decommissioning.
A recent study highlights the urgent need to update design standards in stable continental regions like Peninsular India. The assessment shows that major urban areas are underprepared for earthquakes, with risks exceeding current safety standards.
A University of Alberta study shows that beaver dams create suitable breeding habitats for frogs and toads, with approximately 5,000 species recorded at 54 beaver ponds. The beavers' presence enhances the development and growth rates of frog and toad larvae.
Researchers found that beaver dams enhance hydrologic processes during peak flow and low flow periods, creating environments suitable for wetland formation and persistence. The study suggests that beavers play a crucial role in maintaining ecosystem diversity by altering river systems worldwide.
Researchers found high levels of toxic contaminants in white sturgeon from areas above Bonneville Dam, leading to reduced growth and reproductive fitness. The contamination is thought to be accumulating behind dams, posing a threat to the fish's survival and ecosystem balance.
Scientists have detected a significant increase in glacier quakes and calving events in Greenland, suggesting that the ice is accelerating towards the sea. The researchers hypothesize that the ice is slipping on growing pockets of meltwater, which could be triggered by calving events or stick-slip processes.
Lake Victoria is losing water at an alarming rate due to the operation of Uganda's dams, which have released up to 55% more water than permitted. The lake is now at an 80-year low, with devastating effects on fishing communities and towns.
The study found that wolf exclusion led to a 10-fold increase in elk populations, resulting in decreased beaver lodge construction and disappearance of songbirds dependent on willow habitat. The findings support the role of large predators in conservation and restoration strategies.
Researchers have solved the co-crystal structure of the Dam enzyme in complex with DNA, revealing its role in regulating bacterial virulence. The study offers a potential target for designing rationally designed drugs to inhibit this enzyme's chemical reaction or DNA binding process.
A group of 25 scientists has developed a comprehensive database of 37,099 river restoration projects to draw conclusions about regional and national trends in project numbers, costs, and environmental benefits. The study highlights the need for further research on the environmental effects of different restoration practices.
The river restoration field has matured into a science, with the nation's first comprehensive database of projects documenting trends and progress. Key findings include exponential growth in restoration efforts, with $14-15 billion invested since 1990, and a need for consistent monitoring to improve future efforts.
A global study reveals that 172 of the world's largest rivers are regulated by dams, affecting ecosystems globally. The highest impacted regions include temperate forests and savannahs, while Australia has the largest proportion of free-flowing rivers.
A joint environmental monitoring system was established between Hungary and Slovakia to assess the dam's impact on the Danube River. The authors recommend integrating this system with regional monitoring structures to achieve sustainable management of shared water resources.
Geologists have discovered evidence of massive ice-dammed lakes in the Himalayas, which burst and caused catastrophic floods. The discovery provides new insights into the geological history of the region and its impact on the surrounding landscape.
The Three Gorges Dam Project will conduct the largest and most complete experiment on habitat fragmentation, a condition affecting environments globally. The reservoir's creation will isolate species in limited spaces, providing valuable insights into ecological dynamics.
The institute will revamp the system for collecting generation reports, prepare white papers on wind energy potential and problems, and establish a program to map out California's wind resources. Data on wind resources is over 20 years old, highlighting the need for better forecasting.
The Ecological Society of America advocates for a broader view of freshwater resources, prioritizing ecological needs alongside societal requirements. Healthy freshwater systems provide essential goods and services like food supply, flood control, and habitat, which are costly to replace with technology.
The two new processes, RAM-DSM and RAM-TSM, provide a comprehensive approach to securing dams and transmission systems by evaluating vulnerabilities and consequences of attack. These methodologies are based on formal risk-assessment tools and techniques used by Sandia to protect U.S. nuclear weapons facilities.
The UCSB researchers have developed a cross-protective Salmonella vaccine using the DNA adenine methylase technology, which is also being explored for use in other bacterial and viral pathogens. This breakthrough offers significant potential for combating biowarfare agents and could render current vaccines obsolete.
A recent study by Washington University in St. Louis researchers attributes increased flood levels on the Missouri and Mississippi rivers to the placement of thousands of wing dams, built by the US Army Corps of Engineers in the 1930s and '40s. The structures impede water flow during floods, causing water levels to rise.
Researchers at PNNL and the US Army Corps of Engineers used an acoustic camera to study fish behavior near a dam, capturing images of individual fish at distances of up to 30 feet. The camera provided detailed information on fish size and shape estimates, expanding understanding of how fish react to structures added to dams.
Researchers examine dam removal's effects on rivers, considering ecological, engineering, social and legal perspectives. The symposium explores how dam removal affects nutrient flow, habitat, and flood patterns, highlighting the need for better restoration strategies.
A team of geologists and aid workers warn that the Sarez Lake in Tajikistan is a ticking time bomb, with a natural dam on the verge of breaching. If the dam fails, it could unleash a wall of water devastating hundreds of mountain villages and killing hundreds of thousands of people.