New Research Improves Early Warning of Destructive Megastorms


Via Flickr

Nicole Welle | August 20, 2020

New scientific research will make it easier to predict the path of devastating megastorms and enable communities to better prepare for flooding.

Mesoscale convective systems (MCSs) are megastorms that affect communities all over the world. They can be bigger than the size of England and travel over 600 miles over a period of anywhere from a few hours to two days. They often cause major damage to infrastructure and livestock, and severe flooding triggered by these storms can threaten human lives. In the Sahel region of Africa, MCSs have tripled in frequency since the 1980s due to global warming, according to an article published by the UK Centre for Ecology and Hydrology (UKCEH).

Until now, it was difficult to predict the path of MCSs. However, a new study conducted by the UKCEH found that land surface conditions affect the direction and intensity of megastorms after they form.

“It is well known that heat provides thunderstorms with great energy, but it was commonly thought that once they are moving, they were not affected by the state of the ground over which they travelled. However, we found that drier soils increased the intensity of an MCS mid-storm, affecting the amount of rainfall they release and also where they travel. Conversely, we found storms were often weakened over moister soils,” said lead author Dr. Cornelia Klein of UKCEH.

This new information has allowed scientists to develop online tools to forecast the path and strength of approaching storms – a breakthrough that will increase warning times for affected communities. It may also enable better decision making by town planners and farmers at the center of MCS hotspots and increase the resiliency of their economies.

US Reaches Ten Billion-Dollar Disaster Mark Earlier Than Any Year Prior


Via Flickr

Thomas Robinson | July 28th, 2020

As of July 8th, the US has already experienced ten weather and climate disasters where the losses exceed one billion dollars.

Billion-dollar disasters are weather or climate events that result in losses reaching, or exceeding, one billion dollars in damage costs.  In a concerning trend, the past five consecutive years have all had ten or more billion-dollar events averaging almost fourteen severe events per year.  There have been ten billion-dollar disasters so far in 2020 occurring earlier than any other year prior.   

Climate projections suggest that severe storms will increase in both frequency and intensity supporting the need for increased disaster relief funding to address the prevalence of expensive disaster clean-up.  Surprisingly, the storms responsible for almost half of the billion-dollar disasters since 1980 have been severe thunderstorms rather than hurricanes or floods.

Iowa has recently been involved in the billion-dollar disaster figure with the 2019 Missouri river floods which caused around $1.6 billion in damages.  As weather patterns become more severe, the likelihood storms reach the billion-dollar mark will increase making events like the 2019 floods more common events for Iowans.

New Flood Risk Assessment Suggests Higher Risks Than Previously Thought


Via Flickr

Thomas Robinson | June 30, 2020

A new report from the First Street Foundation shows that flooding risk across the country is likely under represented.

New calculations reported in “The First National Flood Risk Assessment” suggest that almost twice the number of properties have a heightened flood risk compared to the FEMA Special Flood Hazard Area (SFHA) 1 in 100 layer.  The SFHA identifies properties with a heightened flood risk and influences decisions made for flood insurance and housing mortgages. FEMA identifies around 8.7 million properties to be at risk from a 100 year flood while the new risk assessment estimates 14.6 million properties to be at risk. 

To estimate the 14.6 million properties, the new report included small creeks that were ignored on federal maps, rainfall and sea-level rise.  The risk assessment includes areas where flood mapping is either incomplete or out of date which contributes to the increase in the number of at risk properties. 

For Iowa, the report suggested an additional 141,300 properties were at risk in the state compared with the SFHA measure.  The report identified Council Bluffs as the city with the most properties at risk (11,000 properties), followed closely by Des Moines (9,000 properties).

Remnants of Tropical Storm Cristobal Reach Iowa in a Rare Occurrence


Source: NASA earth observatory

Nicole Welle | June 10, 2020

Parts of Eastern Iowa saw heavy rainfall and flash flood warnings yesterday as what was left of Tropical Storm Cristobal moved into the Midwest.

Tropical storms over the Gulf of Mexico usually break up before they reach Iowa, but this one remained a post-tropical depression in an extremely rare phenomenon, according to Meteorologist Brooke Hagenhoff at the National Weather Service. This system brought an abrupt end to the hot, humid weather that eastern Iowans had been experiencing as it was followed by a cold front that brought cooler, dryer conditions, according to an Iowa News Now article.

The post-tropical depression caused heavy rainfall in the state, and flash flooding occurred near waterways and in low areas. Along with posing threats to human safety, flash floods can also raise environmental concerns. Floods have the ability to pick up hazardous chemicals and materials and transport them into waterways. This can threaten the safety of drinking water as well as the plant and animal life that rely on Iowa’s waterways.

Drowning of Coastal Marshland in Louisiana is Likely Inevitable


Via Flickr

Thomas Robinson | May 25th, 2020

Coastal marshes in the Gulf of Mexico have been shown to have tipping points in a new study.  Tipping points, are when coastal marshes are unable to keep up with the rate of sea-level rise and become submerged over time destroying the marsh ecosystem.

Sediment cores were used from the Mississippi Delta to investigate how coastal marshes reacted to changes in their environment over the past 8,500 years.  Researchers found that even a small increase in the rate of sea level rise would result in large areas of coastal marshland becoming submerged.  Researchers found that rates above 3 millimeters per year is the likely threshold for coastal marshes to survive.  Unfortunately, current rates of sea-level rise are beyond that threshold suggesting that the remaining marshes in the Delta will likely drown within the century.

Coastal wetlands, such as marshes, are one of the most valuable ecosystems in the world.  They are extremely productive regions that have significant environmental and economic benefits.  They provide homes for diverse ecosystems that can benefit species diversity which results in robust fisheries.  Coastal wetlands also provide flood protection and erosion control for coastal areas which help to reduce the effect storms have on the coastline.

As coastal wetlands in the Mississippi River Basin are stressed from sea-level rise, they are also inundated with sediment and nutrients flowing from upstream.  Iowa is a major contributor to this issue and even though efforts are underway to alleviate the stress, coastal wetlands will be negatively affected by the state’s agriculture for years to come.

Flood Risk Decreases in the Upper Mississippi River Basin


2020 U.S. Spring Flood Outlook (via NOAA)

Thomas Robinson | April 9th, 2020

In a recent flood forecast update, the National Weather Service predicted that sites within the Upper Mississippi River basin will have a lower risk of reaching major flood stage this spring than previously predicted. 

Dubuque, for example, saw the probability of having a major flood event drop from 51% to 37%.  Even though the decrease in flood risk is encouraging, the flood risk for Dubuque is still well above the historic probability of 12%.

The reason for this decrease in flood risk is that the bulk of spring snowmelt will have moved through the river basin by the end of March.  Even though there is improvement, the river basin still has a high risk of flooding due to the potential combination of residual snowmelt paired with above normal spring precipitation events.

One tool for Iowans concerned about floods is the recently updated Iowa Flood Information System where a statewide sensor network provides real-time information about Iowa’s waterways.

Flood sensor updates to help protect Iowans this spring


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The Iowa Flood Center’s Iowa Flood Information System shows the location of flood sensors throughout the state.

Julia Poska | March 17, 2020

Two major updates to Iowa’s network of flood sensors will help protect citizens and property this spring, when projections predict the state will see major flooding.

The Iowa Flood Center recently received $150,000 from the Iowa Department of Homeland Security and Emergency Management, according to KCRG.  The IFC also received $30,000 from the Iowa Department of Natural Resources. The network’s service provider is phasing-out the previously used technology, according to KCRG, so the funding will provide new modems and data plans to keep the sensors running.

The Iowa Department of Transportation has also installed five new flood sensors along the Iowa-Nebraska state boundary, the Iowa Capital Dispatch reported. Areas in both states along the Missouri River were devastated by floods last spring. With elevated flood risk forecast for this year, the sensors could help Iowa and Nebraska officials coordinate disaster response.

Mussels as water cleaning ‘ecosystem engineers’


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Mussels play helpful roles in river ecosystems (via Creative Commons). 

Julia Poska | March 12, 2020

A group of citizens in Muscatine, Iowa are pushing to restore the over harvested Mississippi River mussel population. The “Mussels of Muscatine” group hopes to create learning opportunities, reverse damage to the river ecosystem and improve water quality.

The group wants to convert a dilapidated pump house into a mussel research and propagation facility, according to the Des Moines RegisterThat plan faces several logistical hurdles, but the idea that mussels could help reverse some of Iowa’s water quality degradation is valid.

CGRER member Craig Just, a University of Iowa associate professor of environmental engineering described mussel’s role as ‘ecosystem engineers’ to the Register. As the molluscs filter nutrients from the water to feed, they remove pollutants like nitrogen. Just said mussels can also remove microorganisms like algae and phytoplankton, which are harmful to ecosystems when their populations explode.

Just pointed to several challenges to restoring the Mississippi mussels as well. Iowa soil erodes into waterways at high rates, which would bury mussels and prevent them from reproducing. Mussels also must eject their larvae into fish gills, a difficult process to recreate in a lab or propagation facility.

EnvIowa Podcast: Talking climate and contamination with Co-Director Jerry Schnoor


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Jerry Schnoor speaking at the release of the 2019 Iowa Climate Statement (photo by Kasey Dresser). 

Julia Poska |March 2, 2020

This week’s episode of EnvIowa features a discussion with CGRER co-director Dr. Jerry Schnoor. He is, among other things, a professor of civil and environmental engineering with a long career studying climate change, water quality and environmental toxicology. Listen to hear Schnoor discuss the urgency of climate change, his efforts to clean up chemical pollution using plants and why he wants our youth to get angry.

Major flooding on Mississippi River likely again this spring


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Most of the Iowa/Mississippi River boundary can expect to see moderate flooding this spring (via NWS). 

Julia Poska | February 20, 2020

Iowa communities along the Mississippi River will most likely see major flooding this spring.

A National Weather Service flood outlook released last week shows an over 50% chance of extensive inundation all along the state’s eastern boundary. Probability of moderate flooding is at 95% in most areas. Western Iowa faces lower, but still significant risk.

Heavy precipitation in 2019, still-saturated soils and heavy snowpack to the north contribute to the elevated flood risk.

Radio Iowa reported that Gov. Kim Reynolds said official are coordinating with local emergency management teams. Reynolds said the Army Corps of Engineers is releasing water already to make room for melted snow to the north.

Last summer’s Mississippi River flooding was the longest in recorded history, lasting nearly 200 days. A coalition of river city mayors estimated damage to be over $2 billion along the length of the river.

You can find 2020 flood outlook data at specific Iowa sites using the interactive feature at this NWS page.