I traveled to the St. Anthony Falls Laboratory (Minneapolis, Minnesota) to investigate the sediment pattern of scour and deposition associated with a circular patch of vertical cyclinders. Although diversion slows flow inside the patch, turbulent vortices form around each solid cylinder, creating scour. A striking pattern of scour inside the patch with deposition behind was observed. For my PhD work (a collaboration with Marcelo Chamecki at Penn State), I will experimentally investigage the behavior of particles over a canopy of submerged vegetation in order to shed light on the trajectory of corn disease particles in the atmosphere.
John Kondziolka
and Dieter Miere
Graduate Students
Emails: kondzi (at) mit.edu and dmeire (at) mit.edu
We study the flow and deposition between and around patches of vegetation. As circular patches of vegetation often develop at nearby locations in a channel or wetlands, we consider the mutual interactions and feedback mechanisms that influence the flow, deposition, and ultimately the morphologic evolution of the rivers or tidal flats. Depending on the spacing between the patches, the flow between the patches may accelerate, inhibit deposition, and cause a sub-channel to form between them. Conversely, the flow between the patches may be diminished, enhance deposition, and cause the patches to merge together over time. Our research will explore the intricacies of these patterns and establish the boundaries of transition between behaviors.
Heidi Nepf
Professor and Principal Investigator
Civil and Environmental Engineering
Email: hmnepf (at) mit.edu
Heidi Nepf's Civil and Environmental Engineering webpage
Professor Nepf's teaching includes Physical Limnology and Transport Processes in the Environment
Alejandra Ortiz
Graduate Student
Email: aleja.ortiz (at) gmail.com
My research is focused on the effect of vegetation patches on turbulence generation and sediment deposition. I use a laboratory flume to simulate a fluvial environment and try to understand how patches of vegetation can change overall flow dynamics and sedimentation spatially. I am interested in how different types of vegetation affect flow dynamics and sediment distribution. So if you have a flexible plant, versus a rigid plant, does it change where sediment will build up. The retention or erosion of sediment preferentially from different areas around and within a patch of vegetation can influence different aspects of the river's ecosystem and physical characteristics.
Brenda E. Pepe
Administrative Lab Support
Email: pepebe (at) mit.edu
I joined the Nepf Lab, (part-time) in June 2011 after working for many rewarding years; first as a legal secretary in downtown Boston and then as a support staff member at Boston College. While working full time at B.C., I enrolled in evening courses at the Woods College of Advancing Studies and ultimately received both a B.A.(1985) and M.Ed. (1989).
Growing up on the Massachusetts' South Shore I enjoyed sailing in local meets for several years. I now make my home in Abington, Massachusetts. I am an avid genealogist; gardener and I try to travel frequently. Additionally, I volunteer my time with the MIT Women's League.
Jeff Rominger
Graduate Student
Martin Family Fellow for Sustainability
Email: jtr (at) mit.edu
I am currently studying the interplay between the shape of flexible aquatic
plants, the dynamic motion of these plants in ocean currents, and how plant
shape and plant motion combine to affect nutrient acquisition and uptake rates
in aquatic environments. In other words: Why do aquatic plants have different
shapes in different environments? What benefits do these changes in shape
confer on the plants? I am working with various species of kelp, a macroalgae,
which exhibit clear morphological differences based on the intensity of the
flow environments in which they live. These morphological differences suggest
that dynamic forces and nutrient uptake can exert strong feedbacks on the
growth and viability of kelp. Using a combination of laboratory experiments
and studies of flexible body dynamics, I am working to unravel some of the
links between the shape of aquatic plants and their physical environment.
Ultimately, I hope that the results of this project will provide insight in
the fields of fluid/solid interactions and plant physiology, and will help
build understanding of how vegetation adapts to and thrives in dynamic physical
environments.