Climate-driven flooding poses well water contamination risks

Read the full story from the Associated Press.

Though estimates vary, roughly 53 million U.S. residents — about 17% of the population — rely on private wells, according to a study conducted in part by Environmental Protection Agency researchers. Most live in rural areas. But others are in subdivisions near fast-growing metro regions or otherwise beyond the reach of public water pipes.

While many private wells provide safe water, the absence of regulation and treatment afforded by larger municipal systems may expose some users to health risks, from bacteria and viruses to chemicals and lead, studies have found.

Risks are elevated after flooding or heavy rainfall, when animal and human feces, dirt, nutrients such as nitrogen and other contaminants can seep into wells. And experts say the threat is growing as the warming climate fuels more intense rainstorms and stronger and wetter hurricanes.

Lake Michigan water-level rise affects inland waterways, study finds

Read the full story from the University of Illinois Urbana-Champaign.

2020 marked Lake Michigan’s highest water level in 120 years, experts said, and climate variance makes future water levels challenging to predict. Coastal impacts are well-documented, but the effect of lake level rise on the area’s inland waterways is poorly understood. A University of Illinois Urbana-Champaign study examined how Lake Michigan’s rising levels affect water quality, flood control and invasive species management within the Chicago-area waterway system that connects the lake to Illinois, Indiana and the Mississippi River basin.

The study, led by civil and environmental engineering professor Marcelo Garcia and graduate student Dongchen Wang, focused on how lake-level rise influences the unique bidirectional flow of the Chicago-area waterway system – initiated by the engineered reversal of the Chicago River in 1900 – and its connection to the Calumet-area waterway subsystem situated along the Illinois-Indiana border.

The Wall of Wind can blow away buildings at Category 5 hurricane strength to help engineers design safer homes – but even that isn’t powerful enough

The Wall of Wind can create Category 5 hurricane winds for testing life-size structures. Margi Rentis/Florida International University

by Richard Olson, Florida International University; Ameyu B. Tolera, Florida International University; Arindam Chowdhury, Florida International University, and Ioannis Zisis, Florida International University

In an airplane hangar in Miami, engineers are recreating some of the most powerful hurricane winds to ever strike land. These Category 5 winds can shatter a test building in the blink of an eye.

Yet they aren’t powerful enough to keep up with nature.

When engineers built the Wall of Wind test facility 10 years ago at Florida International University, it was inspired by Hurricane Andrew, a monster of a storm that devastated South Florida in 1992.

The facility was designed to test structures’ ability to withstand winds up to 160 miles per hour (257 kilometers per hour). Now, we’re seeing the likes of Hurricane Dorian, which shredded neighborhoods in the Bahamas with 184 mph (296 km/h) winds in 2019, and Hurricane Patricia, with winds clocked at 215 mph (346 km/h) off the coast of Mexico in 2015.

A person jumps over debris next to what remains of a home. Its roof is missing, and the walls are askew.
Hurricane Dorian’s Category 5 winds tore apart communities in the Bahamas. AP Photo/Ramon Espinosa

Studies show tropical storms are ramping up in intensity as the climate changes and ocean and air temperatures rise. Designing homes and infrastructure to withstand future storms like Dorian will require new test facilities that go well beyond today’s capabilities – for what we believe should be called Category 6 storms.

The Wall of Wind

There is currently only one life-size test facility at a U.S. university capable of generating Category 5 winds, currently the most powerful level of hurricane. That’s the Wall of Wind.

At one end of the facility is a curved wall of 12 giant fans, each as tall as an average person. Working together, they can simulate a 160 mph hurricane. Water jets simulate wind-driven rain. At the other end, the building opens up to a large field where engineers can see how and where structures fail and the debris flies.

The powerful tempests that we create here allow us and other engineers to probe for weaknesses in construction and design, track failures cascading through a building and test innovative solutions in close to real-world storm conditions. Cameras and sensors capture every millisecond as buildings, roofing materials and other items come apart – or, just as important, don’t fail.

Ten years of research here have helped builders and designers reduce the risk of damage. That’s helpful when forecasters warn, as they do for 2022, of a busy hurricane season with several major hurricanes.

Lessons from hurricane testing

We’ve found in destructive testing that a structure will often rip apart in less than a second. All it takes is the wind penetrating the weakest point.

When Hurricane Dorian hit the Bahamas, many less-well-constructed homes turned into shrapnel, creating another problem. Once a building fails, even nearby homes built to withstand higher winds are in trouble because of the flying debris. Our testing has shown how debris from one building, under continuous winds of 130-140 mph or more, can take out the next building, and then that takes out the next building.

Roofs are often that weakest link. A roof is subjected to uplift force during a storm, so wind hitting the surface of the building needs to be able to escape. When wind runs into objects in that path, it can cause damage.

New designs are improving how buildings stand up to extreme winds. For example, storms can create powerful vortices – winds that swirl almost like a corkscrew at a building’s edge – that can strip away roofing material and eventually lift the roof itself. One innovation uses a horizontal wind turbine along the edge of a roof to diffuse the wind and generate power at the same time, a double benefit.

When wind blows up the side of a building it can create vortices that strip off roofing materials. Horizontal wind turbines attached to rood edges can suppress these vortices, as shown here using smoke, and can also generate power. FIU

The shape of buildings can also either create weaknesses or help deflect wind. You’ll notice that most modern high-rises avoid sharp corners. Testing shows that more trapezoidal or rounded edges can reduce wind pressures on buildings.

And better safety doesn’t have to be costly. One experiment showed how just US$250 in upgrades was the difference between a small, shed-size building standing up to a Category 3 storm – or not. Hurricane straps attach a roof truss to the perimeter of the house. Ring shank nails, which have threads around the shank to grasp the wood, can resist wind forces better than smooth nails. Hurricane shutters also block entry points where the wind can penetrate and trigger catastrophic failure.

Installation also matters, and helps explain why roofs that appear to meet building code requirements can still fail and go flying in hurricanes.

Experiments we conducted have shown how an edge system – the metal elements between walls and the roof – that is installed just half an inch too high or low can prematurely fail at low winds, even though the system was designed to withstand a Category 5 hurricane. Roofers installing asphalt shingles and roofing tiles may need to go beyond the current code when sealing edges to keep them from failing in a storm.

A neighborhood of homes with shredded roofs, some missing most of their roof tiles or shingles, others with parts of the roof missing entirely.
In August 1992, Hurricane Andrew hit South Florida with sustained winds as high as 165 mph. AP Photo/Mark Foley

Expanding testing: 200 mph winds + storm surge

While engineers have been gaining knowledge through testing, the nature of storms is changing as the planet warms.

Warmer temperatures – fueled by increasing greenhouse gas emissions from human activities – enable the air to hold more moisture, and warmer oceans provide more energy to fuel hurricanes. Research shows that bigger and more intense storms that are heavier with water and moving more slowly are going to hammer the areas they hit with more wind, storm surge, flooding and debris.

Storms like these are why we’re working with eight other universities to design a new facility to test construction against 200 mph winds (322 km/h), with a water basin to test the impact of storm surge up to 20 feet (6 meters) high plus waves.

Computers can model the results, but their models still need to be verified by physical experiments. By combining wind, storm surge, and wave action, we’ll be able to see the entire hurricane and how all those components interact to affect people and the built environment.

Disaster testing is finding ways to make homes safer, but it’s up to homeowners to make sure they know their structures’ weaknesses. After all, for most people, their home is their most valuable asset.

Richard Olson, Director of the Extreme Events Institute, Florida International University; Ameyu B. Tolera, Research Assistant at Florida International University – College of Engineering & Computing, Florida International University; Arindam Chowdhury, Professor of Civil Engineering, Florida International University, and Ioannis Zisis, Associate Professor of Civil Engineering, Florida International University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

A heat wave’s lamented victim: The mango, India’s king of fruits

Read the full story in the New York Times.

Blistering spring temperatures have devastated crops of the country’s most beloved fruit. “The soul of a farmer shudders at seeing these fruitless trees,” one grower said.

As destructive wildfires increase, new model can calculate property risk

Read the full story at Construction Dive.

A New York City-based research nonprofit has developed a tool to quantify the risk residential properties face from wildfires, such as those currently ravaging the West Coast

The First Street Foundation Wildfire Model predicts that 71.8 million homes currently have some level of risk and due to climate change, that number will increase to 79.8 million homes by 2050 — an uptick of 11.1%. The organization also has a tool to assess flood risk.

First Street’s free online model supports residential homes and apartment buildings. When attempting to search an address that is mixed-use or commercial, the model provides a message identifying the property as such and will not currently identify a risk level. 

Using a board game to plan for a changing planet

Read the full story in Hakai Magazine.

Two kilometers inland from Hawke’s Bay on the North Island of New Zealand, a dark-red gate just off the highway marks the entrance to the Tangoio Marae. This marae (meeting place) is where a local Māori hapū (community) holds regular gatherings and ceremonies. The location seems perfect: surrounded by lush green hills, close to the city of Napier, and just a stone’s throw from the ocean. But there is one problem: the marae is at very high risk of flooding. The hapū of Tangoio Marae have a serious decision to make about this place that is so central to their community, and one of their decision-making tools is unorthodox: a board game.

Called Marae-opolythe Māori community designed the game in partnership with researchers from New Zealand’s National Institute of Water and Atmospheric Research (NIWA) with the explicit goal of helping the hapū decide how to manage the flood risk to their marae. While the researchers from NIWA contributed scientific data about known flood risks and projected climate change effects, the hapū brought their own experiences and values to the table during game development brainstorming sessions.

The road to success when it comes to mitigating flood disasters

Read the full story from the University of South Australia.

As Australia continues to mop up after one of the wettest years on record, councils might want to consider a new flood mitigation strategy — permeable pavements to suit specific soil and rainfall conditions.

In the Metro East, residents battle raw sewage, flooding — and indifference

Read the full story from St. Louis Public Radio.

In the Metro East city of Cahokia Heights, which includes the former municipality of Centreville, sewer and stormwater systems are often so full that raw sewage seeps into residents’ yards.

“You’d think we live in a Third World country, the way the city don’t care,” said William McNeal, who has lived there for more than 45 years.

The foundation of his house continues to shift because of flood damage. He can’t drink water from the tap, and he regularly has to scare off snakes and mice from the home.

“Where I live, a ditch runs down the side of my house. So all of the water that comes up from Belleville, from all the other places, runs down the side of my house with the trash and stuff, and it sits in my yard [and] goes under my house, and you can’t get it out,” he said. “And the raw sewage too. We couldn’t sit outside because of the smell of the raw sewage … when the sun come out.”

But McNeal said he can’t afford to leave.

And although McNeal and other members of Centreville Citizens for Change have experienced severe flooding for two decades, officials have done little to mitigate the problem — or to even find out what’s causing it.

Clusters of weather extremes will increase risks to corn crops, society

Read the full story from NASA.

Troubles never come singly, the proverb says. A new NASA study shows that the old saying will become increasingly true of climate troubles in a warmer world. The study shows that extreme weather events such as floods and heat waves will increasingly cluster closer in time and space, heightening the risks of crop failures, wildfires, and other hazards to society.

A megafire raged for 3 months. No one’s on the hook for its emissions.

Read the full story in the Washington Post.

Canada and some other nations argue that events such as wildfires and insect infestations are “natural disturbances” that are mostly beyond human control.

Accounting for those emissions against their pledges under the Paris agreement would not only be unfair, they claim, but also obscure efforts to understand the impacts humans are having on the land when theyplant trees, restore wetlands or improve farming practices to store carbon in soil.

Instead, Canada has crafted a sophisticatedsystem to determine whether it is managing its forests in ways that help soak up more carbon over time. But that scientific approach leaves an unresolved political question: Who is actually on the hook for the massive greenhouse gas pollution from megafires, thawing permafrost and other land-related emissions around the world?