Hurricane Harvey worsened by Houston skyline


14742363743_44b261a305_z.jpg
The buildings of Houston made the floods it experienced last August more intense, a new study found (flickr). 

Julia Poska| November 16, 2018

Houston can partially blame the unprecedented flooding it experienced during Hurricane Harvey last year on its skyline. A new study co-authored by Gabriele Villarini, associate professor of civil and environmental engineering and director of IIHR-Hydroscience and Engineering at the University of Iowa, found that Houston’s topography exacerbated Harvey’s rainfall.

Researchers obtained data on rainfall and water discharge in Houston during the storm from various national agencies, and compared it to a computer model that simulated the same storm with a twist. In the model, the city of Houston was replaced with undeveloped farm fields to calculate the built environment’s effect on the storm’s behavior.

The analysis concluded that urban development in the Houston area increased the likelihood of intense fooding 21 times during that particular storm. In other words, if Houston were really an expanse of farmland instead of a city, less rain would have fallen.

“The buildings stop the air from being able to move forward, away from the ocean,” co-author Gabriel Vecchi from Princeton told NPR. “They sort of stop the air in that general area, and the air has nowhere to go but around the buildings, or up.”

Vecchi said when tall buildings push air farther upwards, the amount of atmospheric water vapor that condenses into rain increases. Houston’s skyline not only stalled the storm, but squeezed more rain out of it.

 

 

 

Iowa expects to get drenched


15015873260_551594eea0_z
Iowa expects dark and stormy skies for the next several days (flickr).

Julia Poska | October 5th, 2018

After its third-wettest September on record, Iowa can expect a rainy October, too. The DesMoines Register reported that 4 to 5 inches of rain are forecasted to fall over most of the state in next few days. For some localities, it’s already started.

Southwest Iowa may be hit the hardest. Forecasts there predict 6 or more inches of rain.

The rain is expected to fall almost endlessly at least into early next week. National Weather Service meteoroligst Brooke Hagenhoff told the Register that the widespread nature of the forecast will likely increase the rainfall’s impacts on rivers and low-lying areas.

Some parts of the state are already saturated. Despite a fairly dry start to the month, flood alerts have been active for parts of the Des Moines, Cedar and Iowa Rivers throughout this week thanks to late-September rains in northern Iowa. The Iowa Flood Information System gauged a major flood stage for the Wapsipinicon River at DeWitt as of Wednesday afternoon.

 

How to curb Iowa flooding according to an agricultural engineer


1184195178_9b29039712_z.jpg
Sandbags like these are not an adequate solution to Iowa’s flood problem, Kamyar Enshayan warned (flickr).

Julia Poska| September 21, 2018

In an effort to call Iowa to action, Kamyar Enshayan, director of the University of Northern Iowa’s Center for Energy and Environmental Education, called on his expertise as an environmentalist and agricultural engineer for a Des Moines Register OpEd earlier this week.

Enshayan warned Iowans that flooding will only get worse as the climate changes and gave those upstream three pieces of advice to protect their downstream statesmen.

First, he said we should hand floodplains back to nature. He called for an end to construction and development along riverbanks, arguing that the ecosystem services floodplains provide are more valuable than riverside property.

Natural floodplains improve water quality, provide great wildlife habitat, offer natural flood protection and reduce flood disaster and recovery costs according to the Nature Conservancy. 

Second, we need to make Iowa more “spongy” with sustainable cropping and biodiversity solutions. Enshayan suggested increasing crop diversity in longer rotations to promote healthy soil. Deep-rooted native prairie plants and natural wetland ecosystems will also help contain water.

Finally, he said we must get to the root of the problem and reduce carbon emissions to mitigate climate change. He pointed to methane-emitting landfills and Iowa’s continued dependence on coal as areas for potential improvement.

Enshayan addressed policy makers at the end of the piece, saying they should listen to scientists and engineers like himself to proactively protect people and resources.

“Sand bagging is not enough, not a lasting solution, and does not address upstream problems,” he said.  “Let’s work on lasting solutions.”

 

Iowa Flood Center resources for a soaking wet state


Screen Shot 2018-09-06 at 2.56.22 PM
This image taken from the Iowa Flood Information System shows the accumulation of rainfall in Iowa during the week leading up to this post.

Julia Poska| September 7, 2018

Citizens of Iowa know that with heavy rainfall comes flooding. The last few weeks of rain have served as a very real reminder around the state.

The Iowa Flood Center is a great source of information on current, forecasted and potential floods. Their Iowa Flood Information System in particular offers tools for researchers, city planners,  and even for concerned or curious private citizens.

At first glance, the IFIS may seem overwhelming. Fortunately for the everyday user, the IFIS homepage includes a tutorial video and links to some of the most universally useful features of the system.  These basic tools can be layered with additional information like rainfall, national parks and zip code boundaries, if users so choose.

The Inundation Maps feature shows current conditions at IFS water sensors . Zoom in on a selected area of the state and click on a blue “USGS” box along the water to view the water level at that sensor. Click “More Info” to view the level over time.  You can play with the slider in the panel to the right to see how higher or lower water levels would affect your community.

The Flood Alerts feature shows flood alerts at different stages, from “action” to “major” across the state. Clicking on the triangular alert symbols pulls up the same information about water level that the Inundation Maps feature does.

The River Communities feature dots the state with purple squares representing communities near rivers. Clicking on each will pull up information about future flood outlook and put a border around the upstream watershed so users can see what may be headed their way.

Use these tools during current and future flood hazards to stay informed, keep safe, or simply marvel at the power of nature and technology.

 

On the Radio- Flooding in Polk County


6598271227_72fa0b9077_z
A view of downtown Des Moines (Jason M/flickr)

Eden DeWald | July 30, 2018

This week’s segment discusses the recent flooding in Polk County.

Transcript:

Flooding in Polk County has impacted over five thousand homes this summer.

This is the Iowa Environmental Focus.

A June 30 torrential rain storm brought unprecedented volumes of rain as high as nine inches primarily to Des Moines and surrounding areas, leaving residents displaced and sixteen million dollars in damage to public infrastructure, homes, and businesses.

Des Moines has set aside over eleven million dollars to buy out eighty of the most devastated homes, and is offering interest free loans to its residents for repairs.

And it’s not just the monetary damage. The floods resulted in at least one death when flash-flood waters swept away a sixty-five-year-old man trying to get to safety.

As reported by The Des Moines Register, some of the flood damage to homes and businesses was due in part to insufficient storm sewer systems.

For more information, visit iowa-environmental-focus-dog-org.

From the UI Center for Global and Regional Environmental Research, I’m Sara E. Mason.

New climate predictions for Iowa


8176514882_01eac3d46e_z
Iowa will be facing even hotter temperatures. (Rich H/flickr)

Eden DeWald | July 25th, 2018

Two professors from Iowa recently contributed an article to the Des Moines Register about new climate change predictions for the state of Iowa. Gene Tackle, an emeritus professor of agronomy at Iowa State University, and Jerry Schnoor, a professor of civil and environmental at the University of Iowa and co-director of the Center for Global and Regional Environmental Research at the University of Iowa, wrote about the serious effects that climate change will have for Iowans, and how Iowans are already being effected.

Schnoor and Tackle reference information from the from the Climate Science Special Report which is part of the National Climate Assessment Report. The report found that heat wave temperatures will increase to a range of 97-102 degrees by 2050. Currently, heat wave temperatures fall in a range of  90-95 degrees. These temperatures have serious consequences for vulnerable populations such as the young and elderly, as well as our agricultural interests in Iowa. Extreme weather events, such as the recent flooding in Polk County, have already demonstrated the danger of climate change we are facing today.

Despite Iowa facing these grim predictions, Schnoor and Tackle urge Iowans that they can still take action. Supporting renewable energy, voting in local elections, and joining local organizations that spread information about climate change are all presented as important ways to help protect our future.

 

 

On the Radio- Reacting to flooding in Iowa


2586369708_45c7f90aaf_z
Flooding near Des Moines, Iowa (flickr/Joe G.)

Eden DeWald | July 9, 2018

This week’s segment covers how devastating recent floods in Iowa have been, and what the Iowa Legislature has done to respond to them.

Transcript:

At least 951 presidential flood-emergency declarations have been made in the state of Iowa since 1988.

This is the Iowa Environmental Focus.

A study conducted in part by the Iowa Flood Center revealed that Iowa had the fourth most flood-related FEMA disaster declarations in the country from 1988 to 2016. Fourteen counties, including Johnson and Linn, had more than thirteen declarations in the twenty-eight-year span — about one every other year.

The disasters have amounted to four-point-one billion dollars in crop losses and thirteen-point-five billion dollars in property losses around the state.

After the historic 2008 floods, the Iowa Legislature created the Iowa Flood Center, which has since developed an online tool called the Iowa Flood Information System. The web-based system allows users to see flooding around the state in real time, and help them understand the risk in their homes, farms, or businesses. This resource can help communities better prepare for future floods, or improve land use planning.

For more information, visit iowa-environmental-focus-dot-org.

From the UI Center for Global and Regional Environmental Research, I’m Sara E. Mason.