sand_ripple_slow_Trim.mp4
Research Overview (current & past)
Currently, I am establishing my lab at Utah State University within the Utah Water Research Laboratory and the Department of Civil & Environmental Engineering as a new assistant professor.
As a member of Dr. Aaron Packman's lab at Northwestern, my research focused on understanding how climate and land use practices are altering the fluxes of solutes, organic matter, and sediments from both natural landscapes and built environments.
Through partnerships within the greater Chicago metropolitan area and the Nature Conservancy we are working on understanding the role of green spaces (parks, green roofs, and nature preserves) in reducing urban storm water runoff. Working in the built environment provides numerous benefits and an opportunity to interact with local communities in a meaningful way. These projects have involved a variety of field based monitoring campaigns with distributed high-frequency sensing (take a look at the very cool Waggle and array of things projects).
Concurrently, we are working on a set of projects supported by the National Science Foundation, the Binational Science Foundation, and the Nature Conservancy examining the role of fine sediment transport within rivers. Working across a range of scales we are investigating how fine particles alter physical properties of the river bed, how this feedback impacts the amount of fine particles within the water column during a flood, and how we can predict their fluxes in natural environments. Fine particles play an important role in maintaining aquatic habitat, however they are also a water quality issue when their concentration becomes large.
Magdalena River.mp4By partnering with the Nature Conservancy we are applying these ideas to understand the climatic events responsible for supplying water and sediment to a unique set of wetlands (cienegas) along the Magdalena River in Colombia (see map). A goal of this project is to supply the Nature Conservancy with tools to better quantify the ecosystem services provided by the Magdalena River to mitigate the impacts of hydropower development and climate change on unique these ecosystems.
NSF Postdoctoral Fellowship
As an NSF Earth Sciences Postdoctoral Scholar working under the guidance of Dr. Chris Paola and Dr. Kimberly Hill, exploring the sensitivity of gravel rivers to floods of different shapes and sizes through the use of controlled experiments at St. Anthony Falls Laboratory. These experiments were designed to understand the how a river bed might respond to shifting from a snow melt flood regime (long floods, low magnitude) to one where flash floods are more prominent (short duration, high magnitude). A change many mountain environments may undergo as winter snow pack accumulation decreases with a warmer climate.
Ph.D.
I did my Ph.D. research as a member of the PennSeD group under Dr. Douglas Jerolmack, my research focused on understanding the interactions between the transport of sediment particles and the broader landscape through which they pass. A large part of my dissertation consisted of field work within the Rivers draining the Luquillo Mountains in Puerto Rico as part of the Luquillo Critical Zone Observatory. New to Puerto Rico (at the time) we realized that the Mameyes River was (and still is) an excellent natural laboratory for studying floods, because the river floods all the time. We were interested in understanding how mountain landscapes evolve, which brought us to examining a common variable in many landscapes, sediment. I started with a simple question "how does a flood move sediment, and when it does how far do those particles go?". The field work started by placing 100s of cobbles with RFID tags in the river and tracking their locations after floods.
Over 180 days in the field across four years resulted quite a data set and led us to a much greater understanding of how floods erode, transport, and deposit coarse particles. Given the Luquillo Mountains propensity for creating large flash floods we anticipated the tagged cobbles to move far, but what we found was that they didn't move much farther than the smaller floods. We realized that what appeared to be a large event to us (lots of water), wasn't very large from the perspective of the sediment. Once water starts to spill over the banks it isn't participating in moving sediment on the bottom anymore. This lead to a much greater understanding of the mechanics of rivers and lead to some 'deep' questions, like why are rivers as wide and deep as they are. In the lab, we know that rivers will adjust their size such that they can pass the amount of water you supply them, but in nature the landscape and storms aren't just one size. Rivers seem to solve this problem by adjusting their size such that the average flood is just capable of moving sediment and filling the banks. Flows smaller than this don't exceed the threshold for moving sediment and thus accomplish little in terms of evolving the river, while floods much bigger than this will spill overbank and from the perspective of this threshold to erode sediment they won't look that much larger. This feedback loop that keeps rivers near the threshold of erosion is an important step for understanding how rivers will adjust as climate changes and floods invariably change size and frequency.