Research Questions
Understanding the controls on the morphology and lateral migration behaviors of alluvial rivers
Analyzing the origin and sedimentological properties of scroll bars in modern meandering rivers
Scroll bars are a characteristic feature of meandering river systems, but the relationship between scroll bar morphology, spacing, and the lateral migration history of river channels is still poorly understood. Using high-resolution, lidar-derived DEMs, my recent research studies:
The image at right shows scroll bars from a migrating chute channel (in white) superimposed on scroll bars from the main channel migration (in black). This example is in a paleo-channel belt of the Mississippi River, and the map is a lidar-derived DEM from the Louisiana lidar atlas.
Statistically, the spacing between the chute-channel scrolls and the main channel scrolls is the same! Stay tuned as we figure out why.
Fluvial geomorphology and geohazards
Connecting fluvial planform and sediment distribution with lateral spreading models and observation
Liquefaction after large earthquakes can cause significant ground movement, lateral spreading, that is hazardous and costly. Unconsolidated fluvial sediments are especially at risk for liquefaction, but current geotechnical engineering models of lateral spreading do not account for river planform or sediment distribution. In conjunction with Dr. Ashly Cabas Mijares at North Carolina State University, we are collaboratively investigating:
Understanding the impact of live staking on fluvial geomorphology in central PA
Live staking is a cheap method of stream restoration where live cuttings of woody shrubs are planted along stream banks. This is stream restoration method is rapidly gaining popularity because of how cheap and easy it is, but there are a lack of long-term studies about how live stakes impact stream morphology, floodplain sedimentation, and soil carbon content over time. In partnership with the Penn's Valley Conservation Association, we are monitoring a live staking site near Woodward, PA. Students have done stream surveying, soil sampling, and TOC analysis to establish a baseline for the site, and we will continue to monitor these properties annually to see how live stakes impact the local morphology. It's a beautiful site! Check out some pictures below.
Analyzing the origin and sedimentological properties of scroll bars in modern meandering rivers
Scroll bars are a characteristic feature of meandering river systems, but the relationship between scroll bar morphology, spacing, and the lateral migration history of river channels is still poorly understood. Using high-resolution, lidar-derived DEMs, my recent research studies:
- What is the relationship between scroll bar spacing and the hydrograph of a river system?
- Are scroll bars related to the formative channel width for a given river system?
- Do scroll bars route flow over the bar top, and if so how?
The image at right shows scroll bars from a migrating chute channel (in white) superimposed on scroll bars from the main channel migration (in black). This example is in a paleo-channel belt of the Mississippi River, and the map is a lidar-derived DEM from the Louisiana lidar atlas.
Statistically, the spacing between the chute-channel scrolls and the main channel scrolls is the same! Stay tuned as we figure out why.
Fluvial geomorphology and geohazards
Connecting fluvial planform and sediment distribution with lateral spreading models and observation
Liquefaction after large earthquakes can cause significant ground movement, lateral spreading, that is hazardous and costly. Unconsolidated fluvial sediments are especially at risk for liquefaction, but current geotechnical engineering models of lateral spreading do not account for river planform or sediment distribution. In conjunction with Dr. Ashly Cabas Mijares at North Carolina State University, we are collaboratively investigating:
- How incorporating fluvial geomorphologic variables can improve performance of predictive models of liquefaction-induced lateral spreading
- Which fluvial geomorphologic and sedimentologic variables are sources of variability and epistemic uncertainty
Understanding the impact of live staking on fluvial geomorphology in central PA
Live staking is a cheap method of stream restoration where live cuttings of woody shrubs are planted along stream banks. This is stream restoration method is rapidly gaining popularity because of how cheap and easy it is, but there are a lack of long-term studies about how live stakes impact stream morphology, floodplain sedimentation, and soil carbon content over time. In partnership with the Penn's Valley Conservation Association, we are monitoring a live staking site near Woodward, PA. Students have done stream surveying, soil sampling, and TOC analysis to establish a baseline for the site, and we will continue to monitor these properties annually to see how live stakes impact the local morphology. It's a beautiful site! Check out some pictures below.
Studying fluvial processes over long timescales: what can we learn from the stratigraphic record?
Reconstructing the grain size of paleo-sediment supply
The grain size of the sediment supply is often an overlooked control on fluvial deposit architecture, because it is difficult to reconstruct and is hard to isolate from the effects of accommodation creation, river dynamics, and sediment flux. However, significantly changing sediment supply grain size can be a first order control on river processes and the resulting deposit. My research studies:
Reconstructing deposit preservation from ancient deposits
Some fluvial systems have high lateral mobility and limited sediment accumulation space, which causes them to rework their deposits and move fine-grained sediment downstream. Without metrics to quantify deposit preservation, we have no record of the degree of fluvial reworking in the past. As part of my dissertation work, I:
Currently, I am focused on asking these questions using data from the Devonian-Mississippian Catskill and Huntley Mountain formations in Pennsylvania. This is on-going work with colleagues at Bucknell and Lycoming College. Check out some photos from recent field work below:
Reconstructing the grain size of paleo-sediment supply
The grain size of the sediment supply is often an overlooked control on fluvial deposit architecture, because it is difficult to reconstruct and is hard to isolate from the effects of accommodation creation, river dynamics, and sediment flux. However, significantly changing sediment supply grain size can be a first order control on river processes and the resulting deposit. My research studies:
- How can we examine relative changes in the grain size of paleo-sediment supplies?
- How do fluvial systems store and partition fine-grained sediments between the channel and the floodplain? Does the grain size of the sediment supply influence the storage of fine-grained sediments?
Reconstructing deposit preservation from ancient deposits
Some fluvial systems have high lateral mobility and limited sediment accumulation space, which causes them to rework their deposits and move fine-grained sediment downstream. Without metrics to quantify deposit preservation, we have no record of the degree of fluvial reworking in the past. As part of my dissertation work, I:
- Developed a proxy to measure the reworking of sandy fluvial deposits based on bar form preservation
- Used numerical modeling to study the influence of avulsion dynamics and sediment supply on stratigraphic preservation.
Currently, I am focused on asking these questions using data from the Devonian-Mississippian Catskill and Huntley Mountain formations in Pennsylvania. This is on-going work with colleagues at Bucknell and Lycoming College. Check out some photos from recent field work below:
Research Strategies1) Traditional field methods. Interpreting process origins of multistory fluvial sand bodies, quantifying paleochannel hydraulic properties, and assessing paleo-floodplain character are all field measurements that help tell a story about autogenic (internal to the system) controls on alluvial basin filling.
4) Particle size analysis of sedimentary rocks. Understanding the distribution of mass in sedimentary basins and the origin of sediments. In my Sedimentology Lab at Denison University, we have a brand-new Horiba LA-960 particle size analyzer. This instrument can measure grain sizes from clay to granule size, and we can run samples with both wet and dry methods. If you are interested in collecting quantitative grain size data for your samples, please contact me! |
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