Physical Sciences and Mathematics Commons^™

Multi-Scale Assessment Of Gully Erosion At Road Drainage Outlets, Emma Louise Estabrook

Graduate College Dissertations and Theses

Gully erosion and sediment deposition from roads are underrated sources of sediments entering receiving waterways. While gully erosion has been studied throughout the world, the monitoring of the temporal and spatial erosional processes related to culverts and road drainage is rare. The objectives of this study are to quantify rates of gully erosion from Vermont’s transportation drainage networks at multiple temporal scales and report on insights gained from a multi-scale approach to monitoring gully erosion. To quantify event to seasonal timescales of gully erosion, high resolution terrestrial LiDAR surveys were conducted at 13 field sites. Field sites were monitored at …

Characterizing Mass Loss In Central Cuba Using Long-Term Sediment Generation Rates And Rock Dissolution Rates, Mae Kate Campbell

Graduate College Dissertations and Theses

Knowledge of denudation rates over geologic timescales provides important insight into the processes that govern soil formation, the regulation of Earth’s climate, and the evolution of landscapes. Accurately establishing long-term denudation rates is also key to understanding how human actions have altered the rates and patterns of erosion over time. While cosmogenic nuclides are often used to measure long-term denudation rates at the basin scale, these rates can be unrepresentative of total landscape denudation in areas where significant mass loss occurs through rock dissolution. In tropical landscapes, mass loss by solution often represents a significant portion of total landscape mass …

Human And Natural Controls On Erosion In The Lower Jinsha River, China, Amanda H. Schmidt, Alison R. Denn, Alan J. Hidy, Paul R. Bierman, Ya Tang

College of Arts and Sciences Faculty Publications

The lower Jinsha River has the highest sediment yield rates of the entire Yangtze watershed; these high yields have previously been attributed to a mix of the local geologic setting as well as intensive human land use, particularly agriculture. Prior studies have not quantified long-term background rates of sediment generation, making it difficult to know if modern sediment yield is elevated relative to the long-term rate of sediment generation. Using in situ 10Be in detrital river sediments, we measured sediment generation rates for tributaries to the lower Jinsha River. We find that the ratio of modern sediment yield to long-term …

Stratigraphic Control Of Landscape Response To Base-Level Fall, Young Womans Creek, Pennsylvania, Usa, Roman A. Dibiase, Alison R. Denn, Paul R. Bierman, Eric Kirby, Nicole West, Alan J. Hidy

College of Arts and Sciences Faculty Publications

Landscapes are thought to respond to changes in relative base level through the upstream propagation of a boundary that delineates relict from adjusting topography. However, spatially-variable rock strength can influence the topographic expression of such transient landscapes, especially in layered rocks, where strength variations can mask topographic signals expected due to changes in climate or tectonics. Here, we analyze the landscape response to base-level fall in Young Womans Creek, a 220 km2 catchment on the Appalachian Plateau, USA underlain by gently folded Paleozoic sedimentary rocks. We measured in situ 10Be concentrations in stream sands from 17 nested watersheds, and used …

Characterizing Landscape-Scale Erosion Using 10be In Detrital Fluvial Sediment: Slope-Based Sampling Strategy Detects The Effect Of Widespread Dams, Lucas J. Reusser, Paul R. Bierman, Donna M. Rizzo, Eric W. Portenga, Dylan H. Rood

College of Engineering and Mathematical Sciences Faculty Publications

Concentrations of in situ 10Be measured in detrital fluvial sediment are frequently used to estimate long-term erosion rates of drainage basins. In many regions, basin-averaged erosion rates are positively correlated with basin average slope. The slope dependence of erosion allows model-based erosion rate estimation for unsampled basins and basins where human disturbance may have biased cosmogenic nuclide concentrations in sediment. Using samples collected from southeastern North America, we demonstrate an approach that explicitly considers the relationship between average basin slope and erosion rate. Because dams and reservoirs are ubiquitous on larger channels in the field area, we selected 36 undammed …

Using Long- And Short-Lived Sediment-Associated Isotopes To Track Erosion And Sediment Movement Through Rivers In Yunnan, Sw China, Thomas Bundgaard Neilson

Graduate College Dissertations and Theses

This research aims to understand the natural and human influences on erosion in three tributary watersheds to the Mekong River, Yunnan Province, China and to assess the utility of a novel application of isotopic indicators of erosion. It explores how erosion varies through time and space as a function of physical characteristics of the landscape, tectonic forces, and human alteration of the landscape for forestry and agriculture. To accomplish these goals, I use four sediment-associated radionuclides: in situ 10Be, meteoric 10Be, 210Pbex, and 137Cs. These isotopes accumulate in or on sediment grains, and each accumulates to a different depth on …

Preservation And Sediment Cycling Beneath "Ghost Glaciers": How Cold-Based Ice Dictates Arctic Landscape Evolution, Lee Corbett

Graduate College Dissertations and Theses

Constraining past episodes of climate change and glacial response is critical for understanding future impacts of climate change, especially in the high latitudes where warming is expected to be rapid and most of Earth's glaciers exist. Many studies of past glacier size utilize rare isotopes called cosmogenic nuclides to perform surface exposure dating. Since most areas of Earth's surface that were previously glaciated were covered by erosive ice, which stripped away pre-existing cosmogenic nuclides, surface exposure dating yields the timing of the most recent deglaciation. However, in some high latitude areas where glacial ice is cold-based and non-erosive (so-called 'ghost …

Erosion Rates In Subtropical, Rapidly Developing Countries: An Isotopic Approach To Measuring Background Rates Of Erosion In Brazil And China, Veronica Sosa-Gonzalez

Graduate College Dissertations and Theses

Erosion, a surface process, can be quantified over long-term (assumed to be the natural erosion rate of the landscape) and contemporary (modern) timeframes. My research used the rare cosmogenic isotope 10Be in sand and cobbles collected from rivers in southeastern Brazil (Santa Catarina and Rio de Janeiro states) and southwestern China (Yunnan province) to quantify long-term, background rates of erosion and sediment supply. These measurements will also increase number of such measurements in tropical and subtropical climates. I assessed the relationship between landscape parameters (topographic and climatic) and background erosion rates in order to understand factors related to erosion.

My …