Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Predicting the Extent of Flash Flooding

12.03.2015

Devastating flooding, such as Iowa's Flood of 2008, motivated a team of researchers from the University of Iowa and Iowa Flood Center to analyze a hydrologic model with the potential to predict the extent of flooding based on predicted rain patterns

Devastating floodwaters such as those experienced during Iowa's Flood of 2008 -- which swamped many Iowa communities, along with ten square miles of Cedar Rapids -- are notoriously difficult to predict.


Aneta Goska/Iowa Flood Center

June 2013 Flooding of the Iowa River in Iowa City, Iowa.

So a team of University of Iowa mathematicians and hydrologists collaborating with the Iowa Flood Center set out to gain a better understanding of flood genesis and the factors impacting it. They were able to do this by zeroing in on the impacts of certain rainfall patterns at the smallest unit of a river basin: the hillslope scale.

This week in the journal Chaos, from AIP Publishing, the team describes how they analyzed the nonlinear dynamics of a recently proposed hydrological model at the hillslope-scale under fluctuating precipitation. The study appears as one of a special collection of related articles in the March issue of the journal, which is focused on "Nonlinear Dynamics for Planet Earth." See http://tinyurl.com/kl28r53

The proposed hydrological model that is the subject of the new study "describes a mass balance among volumes of water at the hillslope scale," said Rodica Curtu, an associate professor in the Department of Mathematics at the University of Iowa, working on the project with Morgan Fonley, a graduate student. "Some of these volumes are easily observed, such as ponded water and streamflow, while others such as water in unsaturated areas and saturated zones of soil are more difficult to observe."

When this model is brought to equilibrium, it exhibits a natural tendency to amplify some oscillations but dampen others. "The deciding factor about this behavior is the frequency at which the oscillations are applied to the model via precipitation patterns," she pointed out.

If the hillslope system "experiences a certain frequency of rainfall, the soil becomes the least likely to take in water -- and instead puts it all in the nearest river so the streamflow exhibits large spikes of water," Curtu said. The mathematics involved tap into methods from the theory of nonlinear dynamical systems.

The key significance of this work? Mechanistic description and mathematical investigation of physical processes "can be more enlightening than model calibration, when studying nonlinear phenomena," Curtu said. This is because, she explained, mechanistic, physics-based equations “may not only simulate processes under investigation, but also uncover some of their underlying properties."

"In this case, by using physical parameters to describe a realistic hillslope, we found a pattern of precipitation that yields the greatest -- most amplified -- runoff coefficient, which determines the manner and how fast water will reach the river link."

The team's research sets up a framework by which future hillslope-soil models can be analyzed to predict the worst possible rain pattern that could lead the hillslope to flood, Curtu noted. This can be used to predict the extent of flooding possibilities based on predicted rain patterns.

Next up, the researchers will consider the effects of these streamflow oscillations once they reach the river network. Because the oscillations are occurring separately at each river link, "streamflows interact in ways that can amplify or destroy the oscillations as they combine in the river network," said Curtu.

Since this is a framework for soil models, Curtu and colleagues offer further improvements to the soil model to create a more accurate representation of water in the soil. "Using this framework, we can potentially find other factors that impact the extent of flooding both at the small hillslope scale and at the larger river catchment scale," she added. "Our work will continue in this direction with our Iowa Flood Center collaborators -- Witold Krajewski, Ricardo Mantilla and Scott Small."

The article, "Nonlinear response in runoff magnitude to fluctuating rain patterns," by Rodica Curtu and Morgan Fonley will be published in the journal CHAOS on March 10, 2015 (DOI: 10.1063/1.4913758). After that date it can be accessed at: http://scitation.aip.org/content/aip/journal/chaos/25/3/10.1063/1.4913758

This work received funding from the National Science Foundation (Award Number DMS-1025483).

ABOUT THE JOURNAL

Chaos: An Interdisciplinary Journal of Nonlinear Science is devoted to increasing the understanding of nonlinear phenomena and describing the manifestations in a manner comprehensible to researchers from a broad spectrum of disciplines. See: http://chaos.aip.org

Contact Information
Jason Socrates Bardi, AIP
+1 240-535-4954
jbardi@aip.org
@jasonbardi

Jason Socrates Bardi, AIP | newswise

Further reports about: AIP Flash Flooding flood oscillations physics precipitation rainfall

More articles from Earth Sciences:

nachricht Mountain glaciers shrinking across the West
23.10.2017 | University of Washington

nachricht Climate change weakens Walker circulation
20.10.2017 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>