It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Saturday, February 08, 2020
UNT professor's virtual lab may hold key to preventing undersea oil pipeline leaks
University of North Texas Assistant Professor Oliviero Andreussi. Credit: UNT
Complex organic chemistry experiments often take days or weeks to conduct in a laboratory, but not anymore. Oliviero Andreussi has created a virtual organic chemistry laboratory inside a supercomputer to conduct these same experiments in a matter of minutes.
By using computational chemistry, the University of North Texas assistant professor will begin cycling through scientific databases listing thousands of organic molecules to determine the various effects of different compounds on the production or suppression of natural gas hydrates.
"Natural gas hydrates are crystalline structures made of gas molecules trapped in a cage of water molecules," Andreussi said. "The increase and decrease of the production of these natural gas hydrates could be used to do everything from preventing undersea oil pipeline breaks to storing greenhouse gases."
Natural gas hydrates form in deep-sea sediments in cold conditions and under pressure, the same environment found in undersea oil pipelines. In these pipelines, natural gas hydrates will slowly build up over time creating back pressure that will cause the pipe to crack or burst.
"A large and continuing release of oil into a body of water can be an environmental and economic disaster," Andreussi said. "If we can add an organic compound that will slow or stop the production of gas hydrates we can keep the pipelines intact and help protect the oceans."
Andreussi said there are other environmental applications as well. By increasing natural gas hydrates production, these crystalline structures could, one day, be used to store various gasses.
"Carbon dioxide and other greenhouse cases could be removed from the atmosphere and captured in gas hydrates," he said. "Once in a solid phase, the gasses could be stored or buried. The sooner we find the molecules we need, the sooner scientists can develop other new and exciting applications."
Sheep know the grass isn't always greener when it comes to their health
Sheep appear to forage and avoid parasites differently depending on how healthy they are, according to new University of Bristol research published in Proceedings of the Royal Society B. The study, which used remote GPS sensing data to monitor the foraging patterns of sheep, revealed less healthy animals chose to avoid high-quality vegetation due to a higher prevalence of ticks.
To date, studies which explore how animals are affected by internal factors such as health, and their external environment, such as vegetation and parasite risk, are limited. In this study, researchers from Bristol's School of Biological Sciences and Vet School fitted 23 individual ewes in the uplands of Dartmoor with GPS trackers that were set to record their location every two minutes over a period of eight days.
Researchers then integrated the 114,093 location recordings from the GPS trackers with satellite data of vegetation quality, the field sampling data of tick prevalence, and parasite load and health measures for each sheep.
An analysis of the data revealed that the less healthy sheep (those that were assessed as more anemic) avoided vegetation where ticks are typically found thereby reducing encounter rates and hence infection risk. While the healthier sheep appeared to favor areas providing greater high-quality vegetation and foraging intake despite the potential higher risk of infection from ticks.
Caroline Liddell, a Natural Environment Research Council (NERC) Ph.D. student from Bristol's School of Biological Sciences and the study's lead author, said: "Discovering that the trade-off between maximizing forage intake and minimizing parasite encounter depends on the health status of individual sheep emphasizes the need to study livestock as individuals, even in group-living animals such as sheep. GPS tracking technology provides a feasible and increasingly affordable means of obtaining such individual-level data.
"Our study, which used extensively grazed sheep as a model system, opens new possibilities to study free-living grazing systems, and illustrates the benefits of using GPS technology to advance our understanding in this area.
"Future studies could use controlled interventions, such as antiparasitic treatment, to separate cause and effect and develop understanding of the processes generating the observed associations."
More information: Caroline Liddell et al. Response to resources and parasites depends on health status in extensively grazed sheep, Proceedings of the Royal Society B: Biological Sciences (2020). DOI: 10.1098/rspb.2019.2905
The water cycle describes how water evaporates from the surface of the earth, rises into the atmosphere, cools and condenses into rain or snow in clouds, and falls again to the surface as precipitation. Credit: NASA
U.S. Naval Research Laboratory meteorologist Jeffrey Reid is at the forefront of research studying the role of aerosol particles, and the relationships between the particles with monsoon meteorology, clouds and the sun's radiation.
Aerosol particles floating through the environment harbor big mysteries to scientists globally. The particles range in size from bundles of molecules (10nm) to a grain of sand, and are capable of surfing through the air for thousands of miles. Small and seemingly insignificant on their own, the particles travel as inanimate swarms, influencing the earth's weather and climate in ways scientists do not yet fully understand.
Reid served as the mission scientist for the international field campaign, The Cloud, Aerosol and Monsoon Processes Philippines Experiment (CAMP2Ex), the largest airborne field campaign to date in Maritime Southeast Asia. The NASA-initiated campaign studied tropical weather and aerosols in the South East Asian Region last year from August to October.
As the mission scientist, Reid was responsible for managing the daily operations of the science and flight teams. His efforts ensured the team of more than 150 scientists efficiently and safely collected data despite extreme weather conditions and challenging geophysical features.
CAMP2Ex was a partnership with NASA, NRL, the Manila Observatory, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), and various academic organizations. Researchers on the campaign sought to collect data to answer three key questions:
Do aerosol particles influence weather and precipitation in tropical environments?
Do these influences feed back into the aerosol lifecycle?
How do the aerosol and cloud influence the radiation energy budget of the region?
Filipino scientists were especially interested in the ramifications of monsoonal meteorology on regional hydrology, oceanography and air quality.
With its unique geological features and annual weather extremes, the Philippine Archipelago is an ideal location for scientists to conduct this research. Sitting astride the Pacific Typhoon Belt, 20 to 21 cyclonic storms affect the Philippines annually, and five to six of these storms typically strike the string of islands. These storms have devastating local impacts, but are also an integral part of the meteorology of the Indian Ocean through the Pacific Ocean.
"Being able to predict [major weather events] with greater accuracy and lead time has obvious benefits, not the least of which is keeping people safe," said Hal Maring, NASA CAMP2Ex program scientist.
"We want to get a better understanding of how aerosol particles produced by biomass affects the earth's radiation budget directly and indirectly, and how they interact with clouds relative to precipitation," he said. "If we are going to do climate prediction with greater fidelity, those processes need to be understood."
Their research has international implications for weather forecasting. According to Reid, the information collected from the Philippines could be used to develop models to predict major weather events around the world, including those in the United States. This capability would prove valuable for the Navy, which maintains a constant forward deployed presence.
The hydrological and aerosol cycles: how a speck creates a storm
The hydrological cycle, more commonly known as the "water cycle" is a continuous process of evaporation and precipitation. According to Reid, aerosol particles are an important part of this cycle, because they serve as the nuclei for forming cloud droplets.
Aerosols are produced a variety of ways. Some are human-made pollution, such as car exhaust, biomass burning and industrial emissions. Others occur naturally, like those made up of dust from the Sahara or salt from the ocean.
Every cloud droplet has some airborne particle at its core, according to Reid. That means as the number of pollution particles in the atmosphere change, so too do the number of cloud droplets—as well as their radiative properties, how long they last, and, ultimately, precipitation.
"Chemical reactions happen within those cloud droplets," he said. "So the feedback between emissions, photochemistry, [affecting] how clouds are changed and how the clouds are changing these aerosol particles is complex. We roughly know general types of relationships, but we don't know specifics."
"Some particles get rained out, and some get dumped outside of the cloud. Then they are even bigger and more effective at making larger cloud droplets and it gets recycled back into the clouds. In some cases particles inhibit precipitation. In others they can intensify storms"
International collaboration for a step forward in predicting extreme weather events
A research campaign of this magnitude took extensive coordination between the U.S. and Philippine government and its public, private, and academic organizations. During the campaign, one of Reid's focuses was building collaboration between the researchers and their Philippine counterparts.
In the year leading up to the campaign, Reid and his meteorology and oceanography (METOC) forecasting team worked with the forecasting and flight teams to practice creating forecasts for flight planning. By the time the campaign kicked off, team members had experience producing forecasts and flight plans using actual meteorological data from the vicinity of the Philippines.
"[The forecasts] provided us legitimate prototype plans for us to share with the Philippines to facilitate getting diplomatic clearance as well as basing and overflight permission," Maring said.
During the campaign, Reid, Maring and members of the METOC and flight teams met early in the morning to determine the best locations to fly NASA's P-3 Orion and SPEC Learjet for data collection. Preparing for science flights took hours.
"The ground crew prepped the plane, and we would double and triple-check the meteorology, and triple-check the flight plans," Maring said. "Some of the instruments took hours to warm up."
According to Marring, their Philippine colleagues led the air quality portion of the study, utilizing the instruments on the P-3 to characterize air quality, including suspended particulate matter.
"We were able to get a flight dedicated solely to collecting air quality data in and around the Manilla Megaplex which included measuring upwind and downwind," Maring said. "We were able to make measurements from near the surface, (approximately) 350 feet to over 20,000 feet."
Mission conditions were perfect for this kind of study, according to Reid, providing the wide variety of environments for which the science team was looking. Researchers observed massive smoke plumes from Borneo with megacity pollution alongside pristine air masses and developing tropical cyclones.
Meanwhile, researchers with the Office of Naval Research were also collecting climate data from their Sally Ride research vessel off the coast of the Philippines. For the past five years ONR and their collaborators have been monitoring how regional weather impacts weather across the globe as part of the Propagation of Intra-Seasonal Tropical OscillatioNs (PISTON) program.
"Southeast Asia is a boiling pot for evaporation and convection," Reid said. "Water vapor enters the atmosphere in Southeast Asia and can eventually work its way to the United States. We can pass the information collected here to a mission like PISTON that takes the data and looks at long-range transport and weather all over the Pacific Ocean. At the same time, PISTON observation and modeling efforts support the CAMP2Ex analysis. Ultimately, the science of both missions is tightly coupled."
Researchers, however, will have to wait for the results.
"The region is so complicated we will be analyzing the data for at least another five years," Reid said. "Ultimately we believe this data will stand the test of time."
A growing body of research shows that the behavior of peers has a significant influence on an individual's energy-related decisions, whether it's choosing to install solar panels or to purchase a hybrid vehicle. In short, personal energy choices can be contagious.
But why exactly that occurs is less clear.
In a new paper, an interdisciplinary team of scholars, including an economist at the Yale School of Forestry & Environmental Studies (F&ES), reviews the latest findings on the role of social influence and then illustrates pathways through which these insights might be used to promote more sustainable energy choices.
"The evidence on peer influence in energy has been growing but people haven't connected it to theories in social psychology that can help provide a deeper understanding of how persuasion works, how that word of mouth works, and what are some of the channels by which peer influence makes an impact," said Kenneth Gillingham, associate professor of environmental and energy economics at F&ES and corresponding author on the paper.
"We wanted to bridge those fields of literatures so that we can better understand how peer effects and contagion work, why they work, and why they're so powerful."
The paper is published in the journal Nature Energy. The co-authors are Kimberly Wolske, a research associate and assistant professor at the University of Chicago's Harris School of Public Policy, and P. Wesley Schultz, a professor of psychology at California State University, San Marcos.
In the paper, the authors review existing scholarship conducted across many disciplines—including economics, marketing, sociology, and psychology—on the influence of peer effects. Across these different fields, they write, researchers have found a basic tendency for the energy-related behaviors of individuals to be influenced by members of a peer group; sometimes this influence is an even more important factor than cost or convenience.
For instance, several studies have demonstrated that the chances of an individual deciding to install solar panels increases as more panels are installed in their neighborhood or region. (One study calculated that for each additional installation in one California zip code, the probability of another increased by 0.78 percentage points.)
To better understand why this happens, the authors took a closer look at two areas of research on peer influence that offer important insights:
1. Interpersonal communication and persuasion, which can include observation of energy choices (such as seeing solar panels on a neighbor's roof), word-of-mouth communication, and the influence of trusted community leaders.
2. Normative social influence, in which social norms are passively communicated as shared standards that constrain or guide the behavior within a group.
The authors find the extent to which peer influence affects behavior depends on several factors. These include characteristics of the individual in question (how much have they previously considered a behavior?), the strength of their relationship with their peers, how the individual learns from peer behavior (for example, through conversation, observation, or social comparison), and the depth at which the learned information is processed. "Based on our review of the literature, we hypothesize that certain combinations of these processes are more likely to lead to peer effects in energy than others, depending on the targeted behavior," they write.
For instance, they expect that peer behavior has minimal impact when an individual already has strong beliefs about the behavior in question. If they don't have strong opinions, peer influence can be more powerful.
Also, the effectiveness of different types of peer influence may depend on just how difficult the change in behavior will be. "Receiving a home energy report that shows you consume more energy than your neighbors may be enough to encourage daily conservation," Wolske said. "But we suspect it's less likely to spur investment in durable goods like rooftop solar or electric vehicles."
For behaviors with high upfront costs, people may be more likely to follow suit when they've had an opportunity to talk with existing owners of those technologies. "Friends and family are often among the most trusted sources of information," said Wolske. "Policies and programs that seek to promote low carbon technologies may benefit from enlisting the help of peers who have already adopted them."
The authors suggest that future research should focus on identifying when during the decision-making process social influence is most impactful. They also call for more cross-disciplinary research into the role of peer effects.
"There are surprisingly few conversations across the disciplines about how insights from social psychology and other areas actually underpin the more aggregate findings of contagion in new energy technologies and behavior," said Gillingham. "More interaction between these disciplines can really improve our understanding of why peer effects work and how they can be leveraged to achieve more sustainable energy choices."
Prehistoric oysters from Crystal River are 55% larger than modern oysters. Credit: University of South Florida
Hundreds of years ago, colossal oysters were commonplace across much of Florida's northern Gulf Coast. Today, those oysters have disappeared, leaving behind a new generation roughly a third smaller—a massive decline that continues to have both economic and environmental impacts on a region considered by many to be the last remaining unspoiled coastlines in the Gulf.
The loss of these colossal oysters is at the center of new research from an interdisciplinary team of scientists at the University of South Florida. Led by Integrative Biology Ph.D. student Stephen Hesterberg, School of Geosciences faculty member Gregory Herbert, Ph.D., and Anthropology faculty member Thomas Pluckhahn, Ph.D., researchers utilized prehistoricoystershells, excavated fromarchaeological sitesnear Crystal River, Florida to measure how much oyster size has changed in the area and learn more about the factors that have led to it. The intent is to better understand the habitats of the distant past to help inform the conservation efforts of today.
"Most policy makers and conservationists working in this area are only considering the last 50 years—when we first began actively monitoring these habitats," said Herbert. "Using archaeological data, our work shows that what these systems looked like 100 or 1,000 years ago matters for conservation efforts now."
The region researchers explored is of significant importance, particularly within the oyster industry. Crystal River is within Florida's 'Big Bend' region and is considered one of the last remaining pristine coastal zones with natural oyster fisheries in the United States. However, because this work illustrates huge changes there that were previously unrecognized, researchers now believe the region may not be as pristine as once thought.
"We've been altering the environment in Florida for a lot longer than the 1950's. So, if we don't look at a longer time scale, we might be missing the root causes of why fisheries and marine environments in our state are beginning to collapse," Hesterberg said.
While the loss of large oysters in these coastal regions may not seem like cause for concern, biologists say the ripples caused by their disappearance have had large-scale repercussions. On the one hand, there's the economic impact to an industry that generates hundreds-of-millions-of-dollars annually and relies upon adult oysters of a minimum size to harvest.
There are also environmental concerns. In nature, large animals of all species are uniquely important in terms of their ecological function. Large oysters, for example, have an exponentially greater role in reproductive output and water filtration compared to smaller oysters. Having more offspring helps oyster reefs recover faster after mass mortality events from storms or natural enemies. Slower rates of water filtration mean that estuary waters downstream from oysters are now increasingly muddy, leading to less sunlight penetration and reduced growth of seagrass, a hugely important habitat for a variety of fish.
Researchers also utilized isotopic geochemistry to study the chemical elements within prehistoric and modern oyster shells. This technique allowed them to gain a better understanding of the biological changes that have led to a roughly 2.6 inch decrease in maximum size.
The team found that the lifespan of modern oysters is shorter by about one year compared to their ancestors and that their current rate-of-growth is slower. In an ideal world, restoring Florida's oyster habitats would mean restoring conditions that lead to longer-lived, faster-growing oysters. If that's not possible, the authors add, the filtration rates of prehistoric oyster reefs might still be restored by increasing oyster numbers or densities.
USF researchers hope these new insights can help change the perspective of the current state of Florida's coastal habitats and, in turn, have significant impacts on the direction of conservation and restoration efforts already underway.
A stream channel showing accumulation of fine sediment following the 2009 Station Fire in the San Gabriel Mountains, Southern California. Fine sediment is eroded off steep hillsides during and immediately after wildfire, and then mobilized by debris flows during winter storms. Credit: Roman DiBiase, Penn State
The mudslides that follow wildfires in Southern California can be deadly and difficult to predict. New research can help officials identify areas prone to these mudslides and respond before disaster occurs, according to scientists.
Mudslides, or debris flows, can occur when rainfall washes away the buildup ofsedimentin mountain channels. Roughly equal parts water and sediment, debris flows are strong enough to carry large boulders downhill and threaten communities on or near the mountains. The debris flows in January 2018 that hit Montecito, California, killed 23 people and caused hundreds of millions of dollars in damage. Authorities attributed the mudslides to the wildfires that swept through the area the previous month.
Vegetation holds back the sediment in these steep landscapes, but as the vegetation burns during a wildfire, gravity transports the sediment from the hillsides down to the channel in a process called dry sediment loading, said Roman DiBiase, assistant professor of geosciences at Penn State.
In steep landscapes like those in Southern California, dry sediment loading plays a more significant role in the severity of post-wildfire mudslides than rainfall, shallow landslides and burn severity, according to the scientists. They reported their findings in the February issue of Geology.
"The channels typically are covered with cobbles and boulders that don't move very easily or very often with storms," DiBiase said. "The transported sediment that was trapped behind the vegetation is much finer, so you end up filling the channel with fine-grained materials that make it easier to start a debris flow in the channel itself."
DiBiase and Michael Lamb, professor of geology at the California Institute of Technology, looked at three lidar datasets of the western San Gabriel Mountains. Lidar involves flying a laser scanner over a landscape and sensing the returning light. It allows scientists to reconstruct the topography at a high resolution.
The datasets were collected before the 2009 Station Fire, immediately following the fire and before the first rainfall, and then six years later, after rainfall had led to erosion and debris flows.
The researchers found widespread evidence that dry sediment loading added anywhere from 3 to 10 feet of debris to mountain channels, which were subsequently washed out by rainfall. Channel clearing was absent in areas where dry sediment loading did not occur.
Authorities can use lidar as a rapid response tool to map patterns of sediment loading after a fire and decide which mountain channels to clear before a storm hits, DiBiase said.
The study suggests that understanding how the landscape will respond to a changing climate depends more on soil regeneration rates than future storms.
"Most models assume that you have fully soil-covered conditions on the hillside, so you have an infinite reservoir of material to draw from," DiBiase said. "Our study shows that, at least in the steep landscapes, there's a finite amount of material on the hillside."
The current fire frequency—or time between fires—in Southern California landscapes gives the bedrock enough time to erode and become soil, and vegetation to grow back to hold the soil in place, continued DiBiase.
"If the fire frequency in Southern California doubles, when the next fire hits, the piles of sediment that have accumulated behind the plants are only half full," he said. "So, the volume of debris flows that comes out won't be too high. But we still have some work to do to understand what controls how fast the sediment is produced from bedrock and how quickly these piles fill up."
More information: Roman A. DiBiase et al, Dry sediment loading of headwater channels fuels post-wildfire debris flows in bedrock landscapes, Geology (2019). DOI: 10.1130/G46847.1
Tribal vote nixes plans for radioactive waste storage underground near Lake Huron
by Keith Matheny
Credit: CC0 Public Domain
An Ontario power company has announced it will no longer consider storing low- to intermediate-level radioactive waste within 1 mile of the Lake Huron shoreline, after a local Indian tribe's vote in opposition to the project.
But a similar plan to store underground highly radioactive spent nuclear fuel from Canada's nuclear power plants could still happen in the Great Lakes Basin.
Saugeen Ojibway Nation members on Friday voted to reject a proposed Deep Geologic Repository at the Bruce Nuclear Generating Station in Kincardine, Ontario. The result was 1,058 tribal members voting against the repository, 170 voting for it.
Ontario Power Generation committed in 2013 that it would not build the repository at the Bruce site without support of the tribe.
"OPG respects the decision of SON members," said OPG CEO and President Ken Hartwick in a statement. "We will now move forward to develop an alternate solution."
The repository was to store almost a half-mile underground low- to intermediate-level radioactive waste from OPG-owned nuclear generating stations at Bruce, Darlington and Pickering, Ontario. The waste is currently being stored aboveground, but a more permanent solution in the underground repository was sought.
The vote was "a historic milestone and momentous victory for our people," said Chief Lester Anoquot of the Chippewas of Saugeen Ojibway Nation in a statement.
"We worked for many years for our right to exercise jurisdiction in our territory and the free, prior and informed consent of our people to be recognized," he said.
"As Anishinaabe, we didn't ask for this waste to be created and stored in our territory, but it is here. We have a responsibility to our Mother Earth to protect both her and our lands and waters."
The repository plan garnered almost universal opposition from lawmakers, residents and environmentalists in Michigan and other Great Lakes states, because of its potential, however remote, to contaminate the Great Lakes, a regional economy of 107 million people with a gross domestic product of $6 trillion and the drinking water source for 40 million people on the U.S. and Canadian sides.
OPG officials said deep geologic repositories "are recognized around the world as a scientifically sound solution" for radioactive waste.
"Nuclear energy—as a non-emitting source of electricity—is a vital tool in fighting climate change," Hartwick said. "To enjoy the benefits of this low-carbon, low-cost and reliable source of energy with peace of mind, we must manage the waste responsibly. Permanent and safe disposal is the right thing to do for future generations."
Any new process on a different site for a low- to intermediate-level radioactive waste repository will include engagement with indigenous peoples and interested municipalities, OPG officials said.
But another proposed underground repository, this one for Canada's highly radioactive spent nuclear fuel, is still under consideration, potentially in the same area of Ontario, within the Great Lakes Basin.
The Canadian Nuclear Waste Management Organization (NWMO) late last year announced it has reduced its 22 potential host sites for that permanent underground storage site down to two, with one of them being in Bruce County, Ontario, near the same location as proposed for the low- to intermediate-level radioactive waste.
In January, the organization announced it had reached a combination of purchase and option agreements with landowners in South Bruce to allow technical site evaluations for a potential spent nuclear fuel repository location. The NWMO has committed about $23 million Canadian ($17.3 million U.S.) to secure access to the land in South Bruce.
"Going forward, technical site evaluations and social studies will continue in South Bruce, in southern Ontario, and Ignace, in northern Ontario," NWMO spokesman Bradley Hammond told the Free Press last month. "We expect to identify a single, preferred location for a deep geological repository for used nuclear fuel, to be located in an area with informed and willing hosts, by 2023."
UBCO doctoral student Saeed Mohammadiun says many urban drainage and stormwater systems are not designed well enough to handle extreme weather conditions. Credit: UBC Okanagan
During a typical Canadian winter, snow accumulation and melt—combined with sudden rainfalls—can lead to bottlenecks in storm drains that can cause flooding.
With that in mind, researchers at UBC's Okanagan campus have been examining urban stormwater drainage systems, and they too have concerns about the resilience of many urban drainage systems.
A recently published paper from the School of Engineering says existing design methods for urban drainage systems aren't going far enough to withstand possible catastrophic storms or even unpredictable failures during a moderate storm.
"As engineers, we run simulations of possible catastrophic events, and current systems often do not fare well," says doctoral student Saeed Mohammadiun. "We are seeing sources of overloading such as structural failures, severe rainfalls or abrupt snowmelt stressing these systems."
Add any extreme situation including quick snowmelt or a heavy and sudden rainfall, and Mohammadiun says many systems aren't built to handle these worst-case scenarios. Mohammadiun has conducted several case studies of drainage systems in major urban areas around the world. He has determined many current urban standards designed for a 10-to-50 or even 100-year storm scenario are not meeting the increasing demands of climate change as well as intrinsic failure risk of networks' elements.
"Conventional, reliability-based design methods only provide acceptable performance under expected conditions of loading," he says. "Depending on the system, if something breaks down or there is a blockage, it can result in a failure and possible flooding."
According to Mohammadiun, the resiliency of a system is not just dependent on the load it can handle, but also on its design and build. Many do not take into account the effects of climate change or unexpected weather conditions.
To establish an efficient resilient system, Mohammadiun says it is important to consider various sources of uncertainty such as rainfall characteristics, heavy snowfalls followed by a quick melt and different possible malfunction scenarios along with budget constraints, he says.
"Building or improving the resilience of urban stormwater drainage systems is crucial to ensuring these systems are protected against failure as much as possible, or they can quickly recover from a potential failure," he adds. "This resilient capacity will provide urban drainage systems with the desired adaptability to a wide range of unexpected failures during their service life."
The research points to several measures municipalities can proactively address the issue. Municipalities could build bypass lines and apply an appropriate combination of relief tunnels, storage units, and other distributed hydraulic structures in order to augment drainage system capacities in a resilient manner.
With the recent heavy snowfalls across Canada, Mohammadiun says the silver lining when it comes to drainage is that it takes snow time to melt whereas heavy rainfall puts an immediate stress on these systems. But from the engineering point of view, it is necessary to consider both acute and chronic conditions.
Not surprising, the research shows that urban drainage and stormwater systems that are built or modified to be more resilient, will handle extreme weather events more effectively and efficiently than conventional designs.
More information: S. Mohammadiun et al, Effects of bottleneck blockage on the resilience of an urban stormwater drainage system, Hydrological Sciences Journal (2019). DOI: 10.1080/02626667.2019.1690657
One of the consequences of globalization is the inadvertent human-mediated spread of invasive species. The presence of a new invader, named Obama nungara, is reported in France by an international team led by Jean-Lou Justine ...
Studies on mass shootings assess trends, gauge effectiveness, and recommend policies
by Crime and Justice Research Alliance
In the last decade, thousands have been killed or injured as a result of mass violence in the United States. Such acts take many forms, including family massacres, terrorist attacks, shootings, and gang violence. Yet it is indiscriminate mass public shootings, often directed at strangers, that has generated the most public alarm.
Now, 41 scholars have contributed 16 articles on the topic to a special issue of Criminology & Public Policy (CPP), the flagship policy journal of the American Society of Criminology. The articles assess trends in mass violence and gauge the effectiveness of measures to prevent instances of mass shootings and reduce their lethality. The issue also includes research-based policy recommendations to limit the harm from such violence.
"There are no easy solutions or quick fixes for these horrific events," according to Daniel Nagin, who co-organized the special issue with Christopher Koper and Cynthia Lum, Chief Editors of CPP. "However, there are measures we can take to limit the harm and damage caused by these violent incidents, as well as prevent some shootings from ever taking place. Most of these recommendations require legislative action at the federal and state levels."
New findings from the studies include:
Public mass shootings in the U.S. have become more common and deadly in the last decade: More public mass shooters are motivated to kill large numbers for fame or attention, and experts recommend that the media limit their coverage of shooters to discourage copycats.
Mental illness plays less of a role in violence than assumed: Policies that assume serious mental illness causes mass shootings do little to prevent them and subject millions of nonviolent people with mental illness to stigma and unwarranted social control.
Threat assessments can help prevent violence: Threat assessments using multidisciplinary teams of law enforcement, legal, and mental health experts have been used successfully in schools and recommended for other environments as a feasible prevention strategy. Yet they have not been adopted nationwide, and social awareness campaigns are needed to encourage reluctant bystanders and family members to report suspicious behaviors.
Gun laws can reduce mass shootings: Mass shootings committed with high capacity semiautomatic firearms result in substantially more deaths and injuries than do attacks with other firearms. States with restrictions on large capacity ammunition magazines have fewer mass shooting deaths, as do states requiring firearm purchasers to be licensed through a background check process.
Gun violence restraining orders, or "red flag" laws, provide a way to temporarily disarm high-risk individuals: Preliminary research in California suggests that other efforts to identify and disarm high-risk and illegal gun owners may also hold promise.
Restrictions on gun owners involved in domestic violence may prevent access to firearms for some potential mass shooters: Restrictions can help only if they are obtained through criminal convictions or restraining orders, and only if the firearm restrictions are actually enforced.
Situational crime-prevention strategies should be tested to see if they can prevent public mass violence: Settings can be identified that are at risk of being attacked, leading to more interventions to prevent such attacks or mitigate their harm.
Enhanced response to mass shootings can reduce death and disability: By taking a series of evidence-based steps, hospitals, emergency medical teams, police, and the public can lessen the chances that individuals who are injured will be disabled or die.
More research and effort are needed: The special issue also addresses using machine learning techniques to identify potential mass shooters, using the Internet and social media to study preventing and responding to mass violence, and the need to develop more comprehensive data systems for studying mass violence.
Based on these and other findings in this special issue, Nagin, Koper, and Lum offer the following policy recommendations:
1. Staunch the growth of high-capacity firearms. 2. Curtail access to firearms for dangerous individuals by strengthening background checks for gun buyers, and by instituting extreme risk protection orders, stronger restrictions for domestic violence offenders, and other measures. 3. Improve threat-detection systems through more widespread use of threat-assessment teams, public education campaigns, and social media analysis. 4. Expand training, education, and awareness for first responders, trauma centers, and the public on tactics and strategies that can reduce fatalities when an event occurs. 5. Launch a federally supported effort to formally track mass casualty incidents to support in-depth research and evaluation.
More information: Daniel S. Nagin et al, Policy recommendations for countering mass shootings in the United States, Criminology & Public Policy (2020). DOI: 10.1111/1745-9133.12484
