I am a research professor in the UMass Amherst Geoscience department. I study catchment processes related to sediment and water movement at or near the earth’s surface. I am especially interested in how rivers interact with adjacent aquifers and in the sedimentary and erosion signatures of extreme floods. Here are some current projects that I am working on:

Dams and Sediment on the Hudson– along with collaborators at Woods Hole Oceanographic Inst. and the Hudson River National Estuarine Research Reserve, we are helping river managers and dam owners better understand the sediment impacts of dam removal on the Hudson River estuary.

Historical Perspectives on Sediment Mitigation– Along with Scott Steinschneider and Keith Ahn (both of Cornell), I am studying the sediment archives in one of New York City’s largest water supply reservoirs. NYC is one of five municipalities in the country that holds a filtration avoidance permit from the EPA, allowing them to distribute unfiltered (but treated) water to its customers. This permit was acquired and is maintained through NYC’s exceptional watershed management program, which ensures high quality source water. Sediment in the reservoir’s bottom informs us as to how well various measures over the last century have fared in reducing sediment loading of the reservoir. This is the first paper that has come out of this research.

Ashokan Reservoir – Sediment spills from the inlet proximal west basin into east basin. 1999 Hurricane Floyd.

Dynamic Tidal Marshes – Current and projected rates of sea level rise threaten to drown tidal marshes along coastlines. Tidal marshes mitigate storm impacts to vulnerable coastal infrastructure and provide myriad ecosystem services. I am currently working on marsh systems in coastal Massachusetts and New York that have grown rapidly over the last 100 years. Selected study sites have all experienced a dramatic change in coastal morpholoogy which likely catalyzed rapid marsh growth. By studying the conditions that allowed for rapid marsh expansion, we can better prepare to seed new marshes and restore those that suffer as sea levels continue to rise.

Sustainability and Hydroelectricity– Hydroelectric power is often touted as a clean solution to energy challenges. However, hydroelectric generation comes with myriad well-documented adverse effects. Along with Eve Vogel and others at UMass, I am studying how changes to energy markets have affected the operation of hydroelectric facilities and in turn affected downstream river reaches.

Hydropeaking and Riparian Forests– Hydropeaking – hydroelectic dam releases corresponding to periods of energy demand and price increases – has been shown to cause water to be lost from downstream river reaches. During a release, river water downstream of the dam is pushed into the bank, removing much of it from the river and denying it from downstream users such as farmers, municipalities, and ecosystems. I am studying how this water is taken up by trees and to what extent hydropeaking robs rivers of their water. 


I have a masters of education in secondary science and taught for three years as a Teach for America corps member at a public school in rural Hawaii. As an instructor at UMass, I was awarded the university’s most prestigious teaching award (two awarded per year). Here are some courses that I have taught:

  • Hydrogeology
  • Sedimentology
  • Introductory Geology

byellen < a t > geo.umass.edu