"Anthropogenic and biophysical controls on low flow hydrology in the southeastern U.S." published in Water Resources Research
Excited to announce a new paper has been published in Water Resources Research! This work was done with Dr. Margaret Zimmer and her undergrad, Denise Payan, of UC Santa Cruz. We evaluated 15-years of low flow hydrology in the Piedmont to look for relationships to biophysical and anthropogenic controls. Even in urban watersheds, underlying biophysical controls (precipitation, soils, and topography) still impact low flow magnitude while urban land use is only related to extreme low flows. In contrast, inter-annual variability in low flow is related to land use, with urban watersheds showing less variability than forested. Feel free to email me for a pdf!
My opinion article, written with Jen Glass, Kim Cobb, Minda Monteagudo (all at Georgia Tech), and Alejandro Flores (at Boise State) was published about a month ago in EoS, the American Geophysical Union magazine. In it, we argue that the geosciences need to drop the GRE from graduate school admission criteria, since research clearly shows it does not predict success in grad school. Instead, it is just a barrier to graduate school access. We also include some tips, since all three of our institutions have successfully dropped the GRE. Article is available here:
In addition, if you are a student looking at geoscience graduate programs, I have created a database of all programs that have dropped the requirement. You can see that list here:
In wonderful news, my NSF Hydrologic Sciences grant is officially funded. The project, "Conceptualizing and quantifying the function of beaver dams and stormwater ponds on the hydrology and biogeochemistry of urban streams" will last for three years (8/1/2020-7/31/2023), and I am ecstatic to be working with my colleagues Luke Pangle (GSU), Elizabeth Sudduth (Georgia Gwinnett College), Sandra Clinton (UNC Charlotte), and Diego Riveros-Iregui (UNC). We plan to test a conceptual model of the function of urban beaver ponds at water and solute retention and compare them to stormwater ponds across the Piedmont ecoregion. One MS student has already been recruited for Fall 2020, but I will be looking to recruit two more MS students at a later date. GSU was awarded $324,364 for our portion of the project. Read the full abstract below.
This project will test a conceptual model of how the physical features of urban beaver and stormwater ponds impact streamflow attenuation and water quality. Cities are spending billions of dollars on installing green infrastructure to capture stormwater runoff, when cities in the southeastern U.S. may have infrastructure that fills a similar role already in beaver ponds. The functioning of beaver ponds compared to stormwater ponds has not been systematically studied anywhere. The three project objectives are (1) quantify the nutrient and sediment retention of beaver and stormwater ponds, (2) quantify the transit time of water through beaver and stormwater ponds and floodplain-stream reconnection around dams at both high and low flow, and (3) use remote sensing products and GIS to estimate the total number of beaver ponds in cities and scale-up quantification of retention to the whole-city scale. The hypothesis for objectives 1 and 2 is that the hydrologic and nutrient retention response of the pond will be driven by the hydrologic source of the water—specifically inflows dominated by surface or groundwater—and readily quantifiable metrics of pond geomorphology. The hypothesis for objective 3 is that identified ponded water from aerial imagery can be combined with the drivers of beaver habitat, including stream slope and vegetation, to pinpoint locations of beaver activity. These objectives will be met by closely monitoring 6 sites - 3 beaver and 3 stormwater- over two years in each of three southeastern metropolitan areas: Atlanta, GA, Charlotte, NC, and Raleigh-Durham-Chapel Hill, NC. These 18 sites will be specifically chosen to represent a variety of hydrologic sources and pond morphologies to test the hypothesis driving objectives 1 and 2. Through the development of this conceptual framework, and its rigorous testing using intensive field studies, this proposed research will yield new and transformative knowledge within the field of urban hydrological science. Many factors could drive pond response including, but not limited to, size, watershed land use, sediment, geology, and infrastructure age. Studying ponds across a range of these factors, but with underlying similarities due to their location in the same physiographic region, allows us to narrow in on controlling drivers and predict the response in other systems. In addition, larger-scale mapping of these systems helps scale up to evaluate landscape-level impacts on entire cities. In addition to this intellectual merit, this project will increase diversity in STEM by recruiting underrepresented students to complete M.S. degrees at minority serving institutions, mentored by a diverse group of faculty. The project will also entail public outreach on the ecological benefits of beaver leveraging existing relationships with non-profit conservation groups. Beaver are considered a nuisance species, and thus to reap the benefits their ponds may have on hydrologic and nutrient retention, conversations between watershed managers and beaver pond neighbors must be facilitated to allow for science-based decisions on the fate of these ponds.
Amidst the chaos of the COVID-19 pandemic, Scout Morgan completed her undergraduate honor's thesis looking at the water quality of runoff from green roofs on campus. She found that surface runoff around campus looked pretty similar to precipitation and that runoff water quality from green roofs depended heavily on maintenance practices at the roof. That's not great news for the College of Law roof, where runoff had over 60 mg N/L as the roof's dual purpose as a hang-out spot and stormwater infrastructure lead to fertilizer applications that do not appear to be sticking around in the soil! She also won an honorable mention for climate and a sustainability award at the GSU Undergraduate Research Conference (done virtually) this spring!
Scout is my first undergrad to head off to the world and has been indispensable to running the lab, basically being in charge of the IC over the past year. I don't know how we will manage without her, but wish her the best! She is also a really good kitten rescuer, as you can see here:
Many congratulations to Shellby on finishing her M.S. up with a fantastic presentation at the 2019 AGU conference. We both managed to make it back from San Francisco in time for her to to to graduation to celebrate!