Currently browsing category

Uncategorized

Congratulations to Dr. Colin Bell

Headshot of smiling blond haired white manCongratulations to long-time collaborator and newly minted Ph.D., Dr. Colin D. Bell. Colin has been working on monitoring and modeling the downstream effects of stormwater ponds and wetlands in Charlotte, NC since he started graduate school there in 2011. Five years later, he’s defended his Ph.D. on June 30, 2016 at Purdue University under the mentorship of Dr. Sara McMillan. Colin’s PhD dissertation title was “INFLUENCE OF STORMWATER CONTROL MEASURES ON WATERSHED HYDROLOGY AND BIOGEOCHEMICAL CYCLING.”

Colin was a key contributor to a 2015 paper on using isotope hydrograph separation to understand the contribution of stormwater ponds to urban headwater streamflow. He’s currently got two first author papers in review and much more still left to turn from dissertation to manuscript, so we’ll be seeing more good things coming out of his PhD work for the next several years.

Colin’s next stop is a postdoc with Dr. Terri Hogue at the Colorado School of Mines.

Evaluating bioretention cell and green roof performance in northeastern Ohio

Graduate student Laura Sugano will be representing the Watershed Hydrology lab at this year’s Geological Society of America conference in September. Even though this summer has been very dry, Laura has lots of great data to share with conference goers.

Evaluating Bioretention Cell and Green Roof Performance in Northeastern Ohio

Laura L. Sugano*, Anne J. Jefferson, Lauren E. Kinsman-Costello, Pedro Avellaneda
Kent State University

In urban areas, increased runoff from storm events causes flooding, erosion, ecosystem disturbance, and water quality problems. Green stormwater infrastructure is designed to ameliorate these effects by decreasing the flow rate, overall volume of runoff, and nutrient loads. We compared the effectiveness of a co-located green roof and bioretention cell in order to understand their relative capacities to decrease stormwater runoff and nitrate (NO3-) loads, when subjected to the same weather conditions. Our field site was the Cleveland Metroparks’ Watershed Stewardship Center in Parma, Ohio. Beginning in June 2015, we monitored inflows to and outflows from a bioretention cell draining a paved parking lot and a vegetated roof during 84 storms. Discharge, level, and velocity were measured using an area/-velocity meter at the outflow structure of each site. To assess water quality in water samples, we measured NO3- concentrations using ion chromatography. Event sizes spanned from 0.25 mm to 54 mm. The bioretention cell completely retained flow from 75% of the storm events, and the green roof retained 49% of storms. The bioretention cell completely retained all events smaller than 3.05 mm and the green roof completely retained all events smaller than 0.51 mm. The bioretention cell completely retained 64% of the storm events in summer 2015, 90% in fall 2015, and 77% in winter 2015-2016. The green roof completely retained 37% of the storm events in summer 2015, 48% in fall 2015, and 89% in winter 2015-2016. The groundwater level in the bioretention cell increases in response to storm events and lowers between storms. The soil moisture in the green roof increases during storm events and slowly decreases between storms. NO3- concentration differences between inflows and outflow suggest that more NO3- is removed from inflow to outflow in the bioretention cell than in the green roof. Our study suggests that bioretention cells can decrease stormwater flow and volume and can improve NO3- concentrations better than green roofs because they have the capacity to retain more stormwater and NO3-, due to their thicker substrate and their ground-location, which allows them to retain runoff as well as direct precipitation.

Green plants (sedum) in foreground, road and forest in background.

Vegetation eye view of greenery on the green roof. Photo by A. Jefferson, July 2015.

Long-term simulation of green infrastructure effects at a catchment-scale

The Watershed Hydrology Lab will be represented at the CUAHSI Biennial Symposium in July in West Virginia. Pedro Avellaneda and Laura Sugano have been awarded travel grants to present their research. Here’s Pedro’s abstract:

Long-term simulation of green infrastructure effects at a catchment-scale

Pedro M. Avellaneda1, Anne J. Jefferson2, Jennifer M. Grieser3

1 Department of Geology, Kent State University, 221 McGilvery Hall, Kent, OH, 44242, USA; Phone: 330-672-2680; email: pavellan@kent.edu
2 Department of Geology, Kent State University, 221 McGilvery Hall, Kent, OH, 44242, USA; Phone: 330-672-2746; email: ajeffer9@kent.edu
3 Cleveland Metroparks, 2277 W Ridgewood Dr, Parma, OH, 44134, USA; Phone: 440-253-2163; email: jmg2@clevelandmetroparks.com

ABSTRACT

In this study, we evaluated the cumulative hydrologic performance of green infrastructure in a residential area of the city of Parma, Ohio, draining to a tributary of the Cuyahoga River. Green infrastructure involved the following spatially distributed devices: 16 street side bioretentions, 7 rain gardens, and 37 rain barrels. The catchment has an area of 7.2 ha, in which 0.7% is occupied by green infrastructure and 40% is covered by impervious surfaces. Green infrastructure is expected to treat 72% of impervious areas. The engineered soils for the bioretentions and rain gardens consisted of sand (~72%), organic matter (5-28%), and clay (~10%). Data consisted of rainfall and outfall flow records for a wide range of storm events ?from 0.3 mm to 81.3 mm of measurable precipitation? including pre-treatment and treatment periods. The rainfall-runoff process was simulated for a 10 year period using the Stormwater Management Model (SWMM), a dynamic hydrology and hydraulic model that incorporates green infrastructure. Two scenarios were considered for the application of the SWMM model: pre-treatment, considering observed data before construction of green infrastructure; and treatment, considering observed data after installation of green infrastructure. The calibrated and validated SWMM model was used to evaluate ?using the same climate characteristics? the long-term hydrologic alteration due to the green infrastructure. A 0.8% increase in evaporation, a 12% increase in infiltration, a 1.6% drainage from green infrastructure, and a 14.4% reduction in surface runoff were produced. A simulated flow duration curve for the treatment scenario was compared to that of a pre-treatment scenario. The flow duration curve shifted downwards for the green infrastructure scenario, with a 30% decrease in the Q99, Q98, and Q95 percentiles. Parameter and predictive uncertainties were inspected by implementing a Bayesian statistical approach.

Simulation of the cumulative hydrological response of green infrastructure

As a first product of post-doc Pedro Avellaneda’s work at Kent State, we were pleased to submit the following abstract to the 2016 Low Impact Development Conference. A short version of the work will be published as a conference paper in August, and we are preparing a more detailed version for journal submission this summer.

Simulation of the cumulative hydrological response of green infrastructure

P.M. Avellaneda, A.J. Jefferson, and J.M. Grieser

The performance variability of green infrastructure is connected to the changing dynamics in rainfall-runoff processes. Because of these dynamics, a green infrastructure facility experiences a range of rainfall-runoff events that are difficult to fully capture during a monitoring program. In this study, we evaluated the cumulative hydrologic performance of green infrastructure in two residential areas of the city of Parma, Ohio, both draining to a tributary of the Cuyahoga River. Green infrastructure involved the following spatially distributed devices: 19 street side biorententions, with surface area ranging from 26 to 44 m2; 5 rain gardens, with surface area less than 25 m2; and 43 rain barrels. The engineered soils for the bioretentions and rain gardens consisted of sand (~72%), organic matter (5-28%), and clay (~10%). Data consisted of rainfall and outfall flow records for a wide range of storm events, from 0.5 mm to 89 mm of measurable precipitation, monitored over three years, including pre-treatment (~1 year) and post-treatment periods (~2 years). The Stormwater Management Model (SWMM) was calibrated and validated to predict the hydrologic response of green infrastructure. Optimized parameters, in the form of Posterior Probability Distributions (PPDs), were used to estimate flow attenuation over multiple years of precipitation data in order to capture the complex rainfall-runoff dynamics. The hydrologic performance of green infrastructure was evaluated by statistically comparing the non-exceedence probability plot for pre-treatment and post-treatment outfall flow rate scenarios. In addition, the following probability plots were estimated: (1) ratio of pre-control and post-control total runoff volume, and (2) ratio of pre-treatment and post-treatment maximum peak flow rate. Parameter and predictive uncertainties were inspected by implementing a Bayesian statistical approach. Overall, the cumulative hydrological response of green infrastructure was positive: reductions of up to 33% of peak discharge and 40% of total run-off volume were estimated.

Mammals March Madness – Friends of the Watershed Hydrology Lab pool

Come one, come all to the internet phenom, the most nerdy fun alternative march madness event ever:

Mammals March Madness 2016! http://mammalssuck.blogspot.com/2016/02/mammal-march-madness-2016.html?m=1

Will the snow leopard be upset by the Siberian chipmunk in the first round?* Unlikely. But what happens when the #8 seed Schoolcraft College Ocelots face the #9 seed Quinnipiac Bobcats in the Mascot Mammals division? Who will make the final four? Only science, and a bit of luck, can tell.

If you are on twitter, you can follow the action starting March 7th using the hashtag #2016MMM as the matches are announced live, or you can check back with the post above for updates as the tournament goes on. But the key thing is to go the web page above, print out a bracket and fill it out with your picks for the win. Before the 7th! If you send me a picture/copy of your completed bracket, I’ll track your progress and get a tasty item from Brimfield Bread Oven for the winner of our Kent State pool.

Do we know anything about mammals? Not really. Does that matter? Probably, but Wikipedia, ARKive, and gut instinct let us place our bets anyway.

If this all sounds insane, (it is), ask people like Stuart and Eric who played the last few years and who will vouch for how much fun it is. Or listen to the story that NPR did last year: http://www.npr.org/2015/03/06/391015323/could-a-quokka-beat-a-numbat-oddsmakers-say-yes Or check out the Wikipedia page: https://en.wikipedia.org/wiki/Mammal_March_Madness

Pass the link to the tournament along to your friends.

Can the biologists beat the geologists? Will lab alumni beat the current lab members? Can we get the paleontologists on board this year? Will anyone be able to unseat Elisabeth as the champion of long shot (cute) animals that make good?

Check back here for updates as the month progresses.

* No actual animals are harmed in the course of Mammals March Madness. All battles are simulated based on biology and an element of chance.

Results
Stuart Baker won the pool for overall points, while Lauren Kinsman-Costello and I at least got a mammal into the championship. Verdict: Bread for everyone!

2015 in review (with pictures)

2015 was an incredible year of scientific adventures for the Watershed Hydrology lab. Here are some of our highlights:

Figure 3 from Reilly, D., Singer, D., Jefferson, A., and Eckstein, Y., 2015. Identification of Local Groundwater Pollution in Northeastern Pennsylvania: Marcellus Flow-back or Not?, Environmental Earth Sciences, 73(12): 8097-8109. doi:10.1007/s12665-014-3968-0.

 

These Piper diagrams show the geochemistry of flowback water from fracking operations in the Marcellus shale of Pennsylvania, relative to literature values of groundwater contaminated with road salt, septic waste, and animal manure. The information on these Piper diagrams, along with other geochemical analyses, were used to assess whether alleged contamination of rural, residential well water in northeastern Pennslyvania was likely to be due to the extensive shale gas development occurring in the area. Based on major and trace ion water chemistry, Anne and her coauthors found no evidence of flowback fluid in the tested residential wells. While this work was not definitive proof that flowback contamination is entirely absent, it was a good reminder that contamination of rural, residential wellwater is much more likely to come from leaky septic systems and other less exotic sources.

Figure 3 from Reilly, D., Singer, D., Jefferson, A., and Eckstein, Y., 2015. Identification of Local Groundwater Pollution in Northeastern Pennsylvania: Marcellus Flow-back or Not?, Environmental Earth Sciences, 73(12): 8097-8109. doi:10.1007/s12665-014-3968-0

Figure 7a from Jefferson, A., Bell, C., Clinton, S., and McMillan, S. 2015. Application of isotope hydrograph separation to understand urban stormwater dynamics, Hydrological Processes, 29(25): 5290-5306. doi: 10.1002/hyp.10680.

 

This year I was pleased to find a way to merge her interests in urban hydrology and using water stable isotopes as tools in hydrology. We published a paper that shows that stormwater detention ponds produce distinctive isotopic signatures that can be used to trace the influence of stormwater on the receiving urban streams. Using a two end-member mixing model, my team showed that a stormwater pond in suburban Charlotte, North Carolina had an outsized contribution to streamflow during hydrograph recession periods, thanks to the temporary storage and slow release of water from the pond. For more on this project, you can read the paper or take a look at slides from the talk I gave at the Geological Society of America meeting in November.

Figure 4 from Jarden, K.M., Jefferson, A., and Grieser, J.M. 2015. Assessing the effects of catchment-scale green infrastructure retrofits on hydrograph characteristics. Hydrological Processes, online ahead of print. doi: 10.1002/hyp.10736.

 

Rain gardens and their fancier cousins, bioretention cells, are popping up all over the urban landscape. But how well do they work? Engineers have done an excellent job designing and testing them at the site scale, but few studies have been able to test their effectiveness at larger scales. What happens when a bunch of rain gardens and bioretention cells are added to a neighborhood? Do they make a significant difference in the stormwater runoff entering the local stream? Thanks to a brilliant study design by Cleveland Metroparks, Anne and graduate student Kimm Jarden were able to answer this question with a resounding “Yes, but…” Their paired watershed study showed that the green infrastructure retrofits can very effective at reducing peak and total stormflow, but that seemingly small differences in design and construction can have big ramifications for performance at the neighborhood scale.

This research was highlighted in a press release issued by Kent State in mid-November and was featured in several local news articles.

A bioretention cell from our study. Photo by A. Jefferson, August 2015.

A bioretention cell from our study. Photo by A. Jefferson, August 2015.

 

Bioretention cells, like the one pictured, are designed to capture stormwater runoff and infiltrate it into the ground. Plants use and evapotranspire some of the infiltrated water. In some designs, the infiltrated water moves deeper and recharges groundwater, while in other designs, a perforated underdrain at the bottom of the bioretention cell eventually delivers the water to the storm sewer system – ideally, after the storm has passed.

The picture above is one of the bioretention cells Anne and her collaborators studied in the project above. This bioretention cell has an underdrain, so it probably wasn’t super-helpful at reducing total runoff volumes, but did delay water entering the storm sewer system and receiving stream.

 

Freeze core skillfully collected by graduate student Stuart Baker from a restored stream. Photo by S. Baker.

 

On Thursday at the American Geophysical Union meeting,  graduate student Stuart Baker gave a talk presenting results of his in-progress M.S. thesis research. Stuart’s research examines how subsurface properties of streambeds change in the months and years following stream restoration. Stuart employed a high density array of piezometers to make repeated hydraulic conductivity and head measurements in two streams. At the end of his field work, he extracted freeze cores (“gravel popsicles”) to see if areas near the head of constructed riffles had measurable differences in sediment size and geochemistry relative to riffle tails or pool positions.

The experimental set up from: Griffith, E., Ortiz, J. and Jefferson, A. 2015. HANDS-ON OCEANOGRAPHY. Mimicking the Rayleigh Isotope Effect in the Ocean. Oceanography. 28 (4). http://www.tos.org/oceanography/archive/28-4_griffith.html

 

As part of an NSF-funded project aiming to devise and test methods for improving stable isotope content understanding amongst geoscience undergraduates, my collaborators (with a little help from me) developed a lab module on Rayleigh distillation. This module can be used in an environmental geochemistry class or oceanography class, and is adaptable into a variety of formats (with or without isotope instrumentation, or even just as a data analysis exercise). We’ve written it up so that others can adopt or adapt the technique, and our paper is appeared in the December 2015 issue of Oceanography. The paper and affiliated files (which are open access) have everything you need to use the exercise in your classroom.

West Creek, October 2015. Photo by A. Jefferson

 

The West Creek watershed has been a major focus of our research for the past 3 years, because it is (a) emblematic of the problems facing urban streams; (b) a place where a lot of effort is being put into managing stormwater; and (c) one of the most beautiful urban streams I have ever seen.  This shot of West Creek in Parma, Ohio, was taken on October 24th, when the Watershed Hydrology class field trip visited the stream and nearby Cleveland Metroparks Watershed Stewardship Center.

An innovative cleanup effort in Baltimore’s urban waterways. Photo by A. Jefferson, November 2015.

 

At the Geological Society of America annual meeting in Baltimore, I sought out a fantastic example of an innovative and successful approach to improving urban water quality. The Inner Harbor Water Wheel, affectionately known as Mr. Trash Wheel, is moored at the mouth of Jones Falls, an ultra-urban stream that drains much of the City of Baltimore. Floating rubbish is diverted to Mr. Trash Wheel by booms that span the stream, and the stream’s current powers rakes and a conveyor belt that lift the trash out of the water and deposit it into a dumpster barge. Solar panels power the operation when the stream’s velocity is insufficient to power the water wheel. Thousands of pounds of trash can be removed from the stream per day. As an added bonus, Mr. Trash Wheel has a charismatic Twitter account. Read more about the water wheel at Southern Fried Science and help fund a second one.

Anne on a roof, covered with brown vegetation, dramatic sky

On the (dormant) green roof at Cleveland Metroparks’ Watershed Stewardship Center, April 2015

 

I can’t resist the terrible pun about my work taking me to new heights in 2015. I have a new project monitoring five pieces of green infrastructure at Cleveland Metroparks’ Watershed Stewardship Center, and I’m having a blast learning the ins and outs of this particular site’s green roof, bioretention cells, enhanced swale, and constructed wetland. I have two new graduate students and two fantastic collaborators working with me on the project, and I’m anticipating the arrival of a postdoctoral scholar soon. I think it’s safe to say that my urban hydrology research looks set to soar in 2016.

Research on street-scale bioretention featured in the news

A bioretention cell from our study. Photo by A. Jefferson, August 2015.

A bioretention cell from our study. Photo by A. Jefferson, August 2015.

Our work with Cleveland Metroparks on assessing the effects of retrofitting bioretention cells, rain gardens, and rain barrels into residential neighborhoods in Parma, Ohio has been been featured in several news stories thanks to a nice press release issued by Kent State.

On November 20th, Cleveland.com ran the story: “Kent State University, Cleveland Metroparks project reduces storm water, pollution in Parma neighborhoods

The study was also featured in Cleveland.com’s “best of the beat” roundup on November 22.

The local Record-Courier ran a fantastic feature on the work (unfortunately behind a paywall) on November 30th. They called the article “Kent State professor studies rain gardens’ effect on storm water runoff.

To read the full scientific story of the work, check out our recent publication:
Jarden, K.M., Jefferson, A., and Grieser, J.M. 2015. Assessing the effects of catchment-scale green infrastructure retrofits on hydrograph characteristics. Hydrological Processes, online ahead of print. doi: 10.1002/hyp.10736.

Retrofitting stormwater retention on headwater streets: hydrologic effects of catchment-scale green infrastructure

At the Geological Society of America meeting, Anne will be giving an invited talk in (T106) From Green Roofs and Gutters to Urban Streams: Advancing Urban Watershed Hydrology through Innovative Field and Modeling Approaches. On Monday, November 2nd, at 1:35 pm in BCC room 342, Anne will be talking about:

Retrofitting stormwater retention on headwater streets: hydrologic effects of catchment-scale green infrastructure
Anne J. Jefferson1*, Kimberly M. Jarden1, and Jennifer M. Grieser2
1. Department of Geology, Kent State University, 221 McGilvrey Hall, Kent, OH 44242 kimberly.jarden@gmail.com; ajeffer9@kent.edu
2. Cleveland Metroparks, 2277 W Ridgewood Dr, Parma, OH 44134 jmg2@clevelandmetroparks.com
*corresponding author
Abstract
The detrimental effects of urban stormwater can be lessened by disconnecting impervious surfaces and redirecting runoff to stormwater control measures, but retrofitting stormwater ponds into fully-developed urban landscapes is challenging. Decentralized green infrastructure, such as rain barrels, rain gardens, and street-connected bioretention cells, may be a more feasible and attractive approach, but the catchment-scale effectiveness of such retrofits is poorly understood. In a residential neighborhood in suburban Cleveland, Ohio, a before-after-control-impact design, in which streets served as subcatchments, was used to quantify hydrologic effectiveness of street-scale investments in green infrastructure. On a residential treatment street, voluntary participation resulted in 13.5% of parcels having green infrastructure installed over a two year period. Storm sewer discharge was measured pre– and post- green infrastructure implementation and peak discharge, total runoff volume, and hydrograph lags were analyzed. Green infrastructure installation succeeded in reducing peak discharge by up to 33% and total storm runoff by up to 40%. Lag times increased following the first year’s installation of green infrastructure, in which street side bioretention cells were built with underdrains. In the second year, bioretention cells were built without underdrains and lag times did not change further. We conclude that voluntary green infrastructure retrofits that include treatment of street runoff can be effective for substantially reducing stormwater, but that small differences in design and construction can be important for determining the level of the benefit.

Woodchips and young plants in foreground, rain garden in middle distance, and houses in the background.

Example of a bioretention cell and rain garden studied in this project.

The person behind the science: A podcast interview with Anne

There’s a fantastic podcast called “People Behind the Science” that “explore the lives and experiences of the people behind the research and scientific discoveries of today.” It was my honor to be interviewed on the podcast and talk about my own journey into research and my life outside of science. You can listen to the podcast episode on-line or download it on iTunes. The whole thing runs 43 minutes, and I’ve found it a useful tool for putting my baby to sleep. Hopefully, if you give it a listen, you’ll find it a bit more stimulating!

People Behind the Science logo (from its Facebook page)

The rise of urban hydrology as shown by word usage in Google’s ngrams

Can you see the Clean Water Act in there? And how much newer the phrase “green infrastructure” is?

“Growing up” as a geomorphologist, I learned about stream restoration much more quickly than I did about stormwater management, but the Google Ngrams show pretty clearly that we’ve been talking and writing about stormwater for longer and a lot more than we have about stream restoration.

This is borne out by looking at word usage just within the New York Times. Stream restoration never gets off the horizontal axis, and truthfully neither does “stormwater” management, but as two words “storm water” it’s reached levels of 0.03% of articles since 2000. It’s not much, but at least it’s there at all.