Abundance and Geomorphic Function of Wood in Urban Stream Systems
Blauch, G. and Jefferson, A.
Large wood serves important geomorphic and ecologic functions in streams, as established by research set in relatively undisturbed watersheds. However, the dynamics and function of wood in urban streams has not received similar attention. Previous studies have not clearly distinguished between the effects of low recruitment potential due to developed riparian zones and hydrograph flashiness increasing wood mobility. In order to focus on the effects of hydrograph flashiness, our study focuses on wood abundance and function across urban northeastern Ohio streams where protected riparian buffers offer recruitment opportunities. Impervious surface cover is used as a proxy for urbanization’s effect on the stream hydrology. The frequency and geometry of large wood was surveyed within the bankfull channels in 11 stream reaches, with watersheds that span 0.39 – 88 km2 and 0.56 – 40.1% impervious cover. Geometry measurements cover length, diameter, and planform orientation for individual pieces and smaller jams, as well as 3D structure of significant wood jams in 7 of the 11 streams using Structure-from-Motion techniques. Measurements of the long profiles, stream banks, and streambed sediments provide indications of the geomorphic context of large wood with respect to pool formation, bank erosion, and sediment storage. Preliminary results show a decrease in the occurrence of large wood pieces from 36 per 100m of stream length in the least developed watershed to as little as 1 piece per 100m at higher impervious surface covers. Of those streams with wood stored as both individual pieces and as part of jams, 73% of the total wood (by count) is stored as jams on average. In the most developed, urban watersheds, early re-surveys show that even these larger jams can be mobilized. These results suggest that even though wood is available to the stream, flashy urban hydrographs still have an influence on the presence of wood within urban streams. With large wood often considered in management and restoration practices, protection of the riparian buffer is not enough to maintain the presence of wood – and the geomorphic and ecologic benefits provided by it – in these flashy urban systems.
Garrett get ready to take some data on this wood jam in West Creek, August 2017.
Storage Dynamics Revealed by Water Isotopes Provide Insight into Water Quality Function of Stormwater Green Infrastructure
Jefferson, A., Sugano, L., Buzulencia, H., Avellaneda, P., and Kinsman-Costello, L.
Increasingly popular, stormwater green infrastructure is touted as improving water quality, through filtration and retention that allows plant uptake and biogeochemical processing to occur. Many data sets reveal large inter-storm variability of water quality in green infrastructure effluent, suggesting that internal dynamics that control water transit time may play an important role in the water quality functioning of green infrastructure. We hypothesized that collecting data on water stable isotopes, in addition to solute chemistry, would provide insight into transit times and would help explain variability in water quality flowing out of three forms of green infrastructure. Water isotopes, chemistry, and fluxes were measured from bulk precipitation, inflow, outflow, and surface water storage for a green roof, bioretention cell, and wetland at a site in northeastern Ohio.
On the green roof, outflow isotopes were variable within storms, but flow-weighted averages were similar to bulk precipitation for each event, suggesting transit times of minutes to hours. First flush behavior for solutes was exhibited for some storms and some solutes, but much of the inter-event variability in solute export could be explained by precipitation amount and antecedent dry period of each storm. In the bioretention cell, inter-event storage and release of old water is sometimes observed in the outflow isotopes. Outflow nitrogen concentrations were generally lower when old water was discharged, suggesting that denitrification is occurring within the bioretention cell. However, antecedent dry period also appears to influence nitrogen concentrations, suggesting some discharge of new water even during moderately-sized storms. Isotopic hydrograph separation was possible for some storms in the wetland, and in these cases, solute concentrations in the outflow can be explained by mixing of new water with previously ponded water. Where solute concentrations can’t be explained by mixing, biogeochemical processing may be happening during the storm period.
This work builds on work I presented earlier this year at the HydroEco 2017 (June) and the GSA regional meeting (March).
Soils and Geomorphology of Five Reclaimed Surface Mine Sites in the Cuyahoga Valley National Park, Ohio
Ruhm, C., Jefferson, A., Blackwood, C., Minerovic, A., and Davis, C.
Abandoned mine lands are common to human-altered landscapes. Despite the improvement of remediation techniques, the geomorphic and ecological function of historical abandoned mines persist as a concern to many regions. Cuyahoga Valley National Park (CVNP) is home to ~50 abandoned gravel, sand, and topsoil mines. After mining ceased, these sites were backfilled, compacted, and seeded. Following reclamation, rills and gullies appeared on some steep slopes within the sites. Additionally, reforestation efforts at these sites have not been successful. The causes of these failures are not well understood. Previous studies of coal mines have pointed toward altered chemical properties as a cause of reforestation failure. However, since the CVNP sites lack coal and associated tailings, further research is required to understand how the mining and reclamation affect erosion control and reforestation efforts.
Our research is investigating the geomorphology and soil quality of five of the abandoned mine sites within CVNP relative to four reference sites with similar slope and aspect, but mature forest. We aim to (1) determine the quality of the soils within the sites in comparison to the reference locations, (2) determine if the sites are currently undergoing erosion in exceedance of the reference locations, and (3) inform future reclamation projects to assist in the creation of successful practices.
We have collected ~250 soil samples from the five sites and four reference locations to analyze for grain size distribution, soil pH, concentrations of extractable Al, Ca, Fe, K, Mg, and P, and total C and N. Preliminary results indicate a marked difference in soil pH between the mined (pH 7-8) and forested reference (pH 3.6-6) sites. Measurements of infiltration capacity and bulk density are underway. Preliminary results of bulk density indicate that the density is very high (>2000 kg/m3) in the mined sites, which may be impeding plant growth and promoting overland water flow. Pressure transducers in three gullies on the mined sites indicate water flow during and following intense rainfall, and silt fences are allowing us to quantify sediment flux. Mapping of gully long profiles and cross-sections will enable us to calculate the volume of sediment removed by the gullies since reclamation occurred.
Geological Society of America Abstracts with Programs. Vol. 49, No. 6
One of the sites that Caytie is studying, as it appeared in October 2016. The several acre site was host to invasive Phragmites reeds and a failed tree planting.
Congratulations to the Watershed Hydrology Lab’s two first year MS students for each achieving two big accomplishments. They have both successfully defended their MS thesis proposals, putting them in a great position to be productive on their research this summer. Also, both Caytie and Garrett were awarded Geological Society of America student research grants to help support their research.
Caytie’s work focuses on the soils and geomorphology of abandoned surface mines in Cuyahoga Valley National Park.
Garrett’s work focuses on the abundance and mobility of wood in urban streams.
In January, I launched the #365climateimpacts project, in which I’ll spend a year tweeting stories of the many ways climate change is impacting people, ecosystems, and the earth; ideas for how to communicate about climate change more effectively; and analyses of technologies and policy proposals that show promise for combatting climate change. Here’s what I’ve shared in the last two weeks.
What does a graph like this mean? It means ocean is taking up heat that CO2 emissions would otherwise add to atmosphere.
I got a bit gif happy with today’s #365climateimpacts tweetstream, so you should really head over to twitter to enjoy the thread. I like snow. I like to sled, build snowmen, snowshoe, and how pretty snow is. Loss of snow is one reason I care about climate change. Today it is 57 F and raining steadily here in NE Ohio. I keep thinking about how we’d have a foot of snow if it were cold enough. Instead, I spent an hour in my class talking about the fun ways hydrologists have of measuring snow. With bare ground outside.
The average US snow season shortened by 2 weeks since 1972. Snow covered area is decreasing. The figure below is from the US EPA’s great Climate Change Indicators site, under the heading “Snow Cover.”
This figure shows the timing of each year’s snow cover season in the contiguous 48 states and Alaska, based on an average of all parts of the country that receive snow every year. The shaded band spans from the first date of snow cover until the last date of snow cover.
Climate normals say that my area averages 45″ of snow per winter, but I haven’t seen anywhere near that most of the 5 years I’ve lived here. Of course, 5 years isn’t long enough to identify any trend (I’m not arguing it is), but my experience fits in the pattern of less snowy winters that are being observed across the United States. Here’s some data stretching 60 years. The figure below is from the US EPA’s great Climate Change Indicators site, under the heading “Snowfall.” Red is less snow, more rain.
This figure shows the average rate of change in total snowfall from 1930 to 2007 at 419 weather stations in the contiguous 48 states. Blue circles represent increased snowfall; red circles represent a decrease.
February 8 (National Kite Flying Day):
Good morning, Twitter. It’s National Kite Flying Day! Do you think I can tie that to climate change?
President Obama has been appreciating kite flying, recently.
Back in the day, it wasn’t just surfboards powered by wind. It was big ships. Admittedly, with sails, not kites, but I’m doing the best I can to tie to #nationalkiteflyingday.
Modern shipping produces huge amounts of greenhouse gas emissions and wind is a renewable, carbon-free energy source. One idea is to attach big kites to ships to provide free & CO2-free energy.
It’s the middle of winter & something is seriously wrong with Arctic sea ice. Sea ice hit record low extents in November, December, and January. Nice reporting at Mashable by Andrew Freedman.
This figure shows the percentage of the land area of the contiguous 48 states where a much greater than normal portion of total annual precipitation has come from extreme single-day precipitation events. The bars represent individual years, while the line is a nine-year weighted average.
A “pineapple express” atmospheric river takes aim at California in December 2014. (NOAA/NASA GOES image)
Minnesota Public Radio ran a fantastic feature on how climate change is affecting ice cover on Lake Superior between Bayfield and Madeling Island, Wisconsin. For 250 year-round residents of the island, winter offers an ice road and the freedom to move back and forth without being tied to the ferry schedule. Except that, for two years running, the ice hasn’t been thick enough to drive on and the ferry has run all winter. This story is personal for me, because my family has owned land on Madeline Island for 4 generations, and I remember the thrill and terror of driving the ice road on winter visits.
The view from our family’s land on Madeline Island, February 3rd, 2017. Photo courtesy of J. Jarvis.
On March 15th, I’ll be at the Cleveland Metroparks Watershed Stewardship Center in Parma to talk with a very special group of people: the people in the Watershed Volunteer Program. The volunteers in this program take part in the active management and monitoring of the park system, becoming certified watershed stewards after completing a certain number of learning modules. I’m excited to get to share our research on the functioning of the stormwater features on the building and grounds of the Watershed Stewardship Center. I expect I’ll get many good and tough questions from the volunteers.
Kent State Green Infrastructure Research Update
Wednesday, March 15
6 – 7:30 p.m.
Watershed Stewardship Center at West Creek
In the pursuit of innovative ways to better manage stormwater, practitioners are increasingly adopting green infrastructure over traditional “grey” infrastructure. Green infrastructure utilizes natural processes to treat runoff and manage flooding. Join us for a presentation from Kent State University on research on the various green infrastructure practices installed around the Watershed Stewardship Center at West Creek. We’ll hear more about how well these installations are functioning and discuss the significance of the results.
Here I am giving a talk at the Watershed Stewardship Center in December 2015.
Our changing climate is already affecting lives in a multitude of ways, and the impacts of climate change will only increase as the world continues to heat up. But because climate operates in the background, it’s easy to ignore the magnitude of the changes happening around us, as we are caught up in a daily news cycle and the rhythms of our own lives. 2017 seems fated to be an eventful – and exhausting – year and it would be all too easy to put climate change on the back burner, while facing seemingly more urgent crises. But, the longer we avoid tackling climate change head on, the more dramatic the impacts we are going to be facing.
I quietly launched a new personal project in January, and now that I’m a month in, I’m ready to tell you about it. I’m tweeting one climate change story per day for each day in 2017, with the tag #365climateimpacts. I’m aiming to tweet timely news stories or compelling visualizations across a wide range of climate change impacted arenas, from oceans to ice, from food to energy, from policy to theology, and more. While I’ve tagged the tweets with the word impacts, I’ll cover climate science and climate solutions as well as the impacts of past, present, and future climate change.
My goals for this project are three-fold:
For those of us who are climate concerned, my goal is to keep climate change on the front burner of our collective agenda with daily reminders of the pervasiveness and magnitude of climate change implications and the hope that individual choice and policy and technological solutions have to offer.
For those who are climate cautious or disengaged, I hope that the in the diversity of topics I tweet at least one will make it across your timeline and resonate with you and the things you care about. We know that just piling on facts doesn’t change people’s minds, but finding a genuine connection is a first step towards a real dialogue. As much as a one-to-many, 140-character limited platform lets me do, I hope I connect with you at some point this year.
The term “Climate Change” is now loaded with so much political baggage that it becomes almost impossible to hold a discussion across political lines. In stakeholder interviews, people generally understand and acknowledge the impacts of climate change on local and regional scales, as long as you don’t call it “Climate Change”. This has been my experience working in rural coastal communities, which tend to be strongly conservative and intimately connected to the changing ocean.
Which is why, when I talk about Climate Change, I don’t talk about science.
When I talk about Climate Change, I talk about Fishing.
A warmer atmosphere can hold more water, so it’s not too surprising that the hottest year on record also had the most precipitable water in the atmosphere. Still it’s nice to see the physics theory borne out in the data.
Annual precipitable water in 2016 at the global scale was at record levels according to R1 Reanalysis (1948-present). pic.twitter.com/WRWNyYo1lT
Scientists like me study carbon emissions, deforestation, ocean acidification, desertification, sea-level rise, glacial melting, landscape degradation, groundwater salination, invasive species, global warming and more. There is very little good news to share. Today’s environmental problems are easily big enough to eclipse our inadequate solutions. When people tell me that climate change makes them feel hopeless, I breathe deep, and then I respond. I don’t answer them because I have a good response, but because we all deserve at least a bad response. Here is what I say.
The way I personally counter the despair that reading the latest climate change news can bring is by thinking about all of the technologies and solutions we already have in hand, and how the economics are steadily working ever more in their favor. President Obama makes a strong case for “The irreversible momentum of clean energy” in a policy forum article in Science magazine. I have a feeling Obama (2017) is going to be a highly cited paper over the next few years.
The mounting economic and scientific evidence leave me confident that trends toward a clean-energy economy that have emerged during my presidency will continue and that the economic opportunity for our country to harness that trend will only grow.
Days before handing over power to a Republican administration, the EPA managed to complete a mid-term review of greenhouse gas emissions standards for cars – more than a year ahead of schedule. Wired has the story:
By 2025, cars would have to nearly double their average fuel efficiency (a kind of measure of emissions) and deliver, on average, more than 50 miles per gallon (which, for arcane reasons, equates to a real world figure of 36 mpg). The auto industry caved and agreed, with the caveat that by April 2018, the EPA and National Highway Traffic Safety Administration do a thorough review of the rules, and adjust them if they proved unduly expensive or just plain unworkable.
By completing the review early – and finding the standards appropriate – the EPA just made it harder for the next administration to take a step backwards on car emissions.
There is, right now (as of Jan 12th), the least area of sea ice on our planet that we've ever measured—probably the lowest in millennia. pic.twitter.com/6LrUKxBEOF
There’s some debate over whether we should really be lumping the Arctic and Antarctic onto the same plot, but there’s no denying that this is a pretty stunning departure from recorded history of sea ice.
We knew it was coming, but January 18th is when NOAA and NASA confirmed that 2016 was the hottest year on record, beating out its immediate predecessor.
2016 was hottest year on record-again. They aren't anomalies. We can explain them w physics. Climate change is real. https://t.co/QXSmq06YkY
We show that over the past 50 years, the population of emperor penguins (Aptenodytes forsteri) in Terre Adélie has declined by 50% because of a decrease in adult survival during the late 1970s. At this time there was a prolonged abnormally warm period with reduced sea-ice extent. Mortality rates increased when warm sea-surface temperatures occurred in the foraging area and when annual sea-ice extent was reduced, and were higher for males than for females. In contrast with survival, emperor penguins hatched fewer eggs when winter sea-ice was extended. These results indicate strong and contrasting effects of large-scale oceanographic processes and sea-ice extent on the demography of emperor penguins, and their potential high susceptibility to climate change.
A stunning visualization of the trends in global temperature over the last 150 years in this temperature spiral, posted by Climate Central.
Global temperature spiral, updated to include 2016 data. Created by Ed Hawkins.
Climate change is already affecting Ohio. Find out how climate change affects your state, on this fantastic climate impacts site (produced by the Federal Government): https://statesummaries.ncics.org/ (Note: If this site disappears, I have copies of the info for the states where I’ve lived: OH, NC, OR, MN).
One of three key messages on climate change impacts being experienced by Ohio. The others focus on increasing temperature (and risks for urban areas) and increasing drought risks. What are the key messages for your state?
Unsure how things like volcanic eruptions and air pollution play into the climate change we are experiencing? This data visualization from Bloomberg does a nice job showing how we can’t explain historical temperature trends without CO2 emissions, and what roles other factors have been playing in the temperature record.
Peatlands are natural storehouse of carbon from the atmosphere — unless they are destroyed. Then, all the carbon goes back up into the atmosphere. Scientists have recently mapped a huge peatland in the Congo basin. It’s estimated to store the equivalent of 20 years worth of fossil fuel emissions from the United States, over an area the size of New York state. Let’s work to make sure it stays protected and the carbon stays in the ground.
Are you watching Katherine Hayhoe’s Global Weirding series of videos yet? You should. One thing I love about Dr. Hayhoe is how clearly she explains why a “just the facts” approach won’t work to convince people skeptical of climate change’s reality. That’s the focus of the latest episode of her series.
Average change in population affected per country given 4?C global warming. Hatching indicates countries where the confidence level of the average change is less than 90%. Figure copyright EU, used in spirit of fair use.
In a month filled with signs that the new US administration will roll back federal comittments to combatting climate change, California is a beacon of light. The state of California, one of the world’s largest economies in it’s own right, is continuing forward with its efforts to decrease its greenhouse gas emissions. As California knows, once the groundwork for a low carbon future is laid, the economics of going backward don’t make sense.
“There’s a whole ecosystem built to reduce emissions,” said Jon Costantino, an environmental policy advisor who previously worked at the California Air Resources Board. “There’s investors, there’s businesses, there’s consultants.”
He added, “To pull the rug out from under that would have a dramatic impact.”
Yesterday, I posted an epic analysis of my scientific reading habits in 2016, but I didn’t tell you about the papers I read last year that made my heart sing. And I didn’t take much time to brag about my own contributions to the scientific literature. So I’m going to rectify that omission today.
My top 3 papers of 2016 are (in no particular order):
The whole thing is absolutely worth reading (and it’s not behind a paywall) but here’s where it really starts to hit home:
Two main challenges stand in the way of achieving a diverse geoscience workforce representative of society: we need to attract more people who have not been wearing checkered shirts, walking boots and rucksacks since secondary school, and we need to retain them.
I am a sucker for a good mega-paleo-flood story, and this one ticks all of the right boxes. An earthquake generates a landslide, which dams a river, and then fails, resulting in one of the largest floods of the last 10,000 years and alters the course of Chinese history. Geology, archaeology, and history combine in this compelling story.
Plus, a bonus paper, that was definitely one of the best papers I read in 2016.
I’m cheating a little bit here, because this paper came out in 2015. But I read this paper in 2015, and then I read it twice more in 2016. That’s how much I like it. Why? Because it’s a really nice illustration of how physically-based models can reveal the complex and unexpected ways that ecosystems and watersheds respond to urban environments. In a semi-arid environment, deep rooted vegetation can take advantage of the bonus water that gets delivered from rooftop downspouts that drain out onto the land. The additional water use boosts net primary productivity, potentially enough to offset the loss of productivity that occurred when parts of the landscape were paved and built upon. But while deep rooted vegetation, native to the semi-arid landscape, can take advantage of the bonus water, grass can’t. It’s a cool story, with implications for the way we develop and manage urban landscapes – and the way we model them. (This paper is open access as of January 1, 2017!)
I was thrilled to be able to contribute to 3 papers in 2016.
In 2015, my team published a paper showing how the installation of bioretention cells, rain gardens, and rain barrels on a residential street in the Cleveland area substantially decreased stormwater runoff. This paper represents the other side of the story – the side that is, just as important (if not more so) – how the people on the street responded to the addition of this green infrastructure. In short, getting residents on board with stormwater management is a big challenge that we’re going to face as we scale-up from demonstration projects to widespread deployment of these technologies. (This paper is open access and free to all.)
I’m thrilled that first author Colin Bell completed his doctorate in 2016 and got two papers out to boot. These papers are the culmination of 5 years of research in Charlotte, North Carolina. In the Journal of Hydrology, we try to disentangle the effects of stormwater management from the overall signal of urbanization across 16 watersheds. It turns out that for the level of stormwater management we see in the real world, it’s not enough to counter-act the effects of impervious surfaces (pavement and rooftops) as a driver of the hydrologic behavior of urban streams. In Environmental Management, we aim to understand the influence of stormwater ponds and wetlands on water quality in the receiving streams. This turns out to be quite tricky, because the placement of stormwater management structures spatially correlates with changes in land use, but based on differences in concentration between stormwater structure outflow and the stream, we show that it should be possible. This echoes the findings from our 2015 paper using water isotopes to understand stormwater management influences at one of the same sites. Colin will have another paper or two coming out of his modeling work in the next year or so, and we’re still analyzing more data from this project, so keep your eyes out for more work along these lines.