Geomorphology Commons^™

Geomorphic Response To Catastrophic Flooding In A Karst Mountain Stream System, Brighton-Blue Hole Watershed, Southwest Jamaica, Sarah M. Letarte

MSU Graduate Theses

The geomorphic effects of flooding are poorly understood in the karst, mountain watersheds along the southwest coast of Jamaica. This study describes the flow path and geomorphic response of an extreme flood event in the Brighton-Blue Hole watershed (BBHW) (6.8 km²) near Belmont, Westmoreland, Jamaica. A tropical depression classified as a >100-year rainfall event produced 32 inches of rain in a 24 hour period in Westmoreland on June 12, 1979. For this study, geomorphic indicators of flood disturbance in BBHW were assessed in 2017-18, finding that channel system responded to the flood with channel incision, debris flows, and …

Numerical Modeling Of Wave Dynamics And Sediment Transport Near The Mississippi Birdfoot Delta And Barataria Estuary, Soroush Sorourian

LSU Doctoral Dissertations

The Barataria Basin is a large estuarine system in Southeastern Louisiana, connected to the Gulf of Mexico through a number of inlets, the most important of which is the Barataria Pass. This research examines, during April-June 2010 including both cold front passage and calm summer-time wind regimes, the wave dynamics in this basin and in its major inlets, morphological evolution near the Barataria Pass, and the budgeting and dispersal of the Mississippi River sediment in the birdfoot delta region. An unstructured grid, terrain following, high resolution coupled FVCOM-SWAVE-SED model is employed and validated in this study. The numerical model results …

Shoreline Dynamics Along A Developed River Mouth Barrier Island: Multi-Decadal Cycles Of Erosion And Event-Driven Mitigation, Christopher J. Hein, Andrrew R. Fallon, Peter Rosen, Et Al

VIMS Articles

Human modifications in response to erosion have altered the natural transport of sediment to and across the coastal zone, thereby potentially exacerbating the impacts of future erosive events. Using a combination of historical shoreline-change mapping, sediment sampling, three-dimensional beach surveys, and hydrodynamic modeling of nearshore and inlet processes, this study explored the feedbacks between periodic coastal erosion patterns and associated mitigation responses, focusing on the open-ocean and inner-inlet beaches of Plum Island and the Merrimack River Inlet, Massachusetts, United States. Installation of river-mouth jetties in the early 20th century stabilized the inlet, allowing residential development in northern Plum Island, but …

Lead Contamination Of Soils In An Abandoned Rifle Range, Augusta County, Virginia, Logan Mahoney

Senior Honors Projects, 2010-2019

Presence of high concentrations of Lead within the soil and water could lead to various health related impacts on humans and wildlife. Exposure to Lead short termly or long termly could lead to many detrimental impacts due to Lead poisoning. The overall concentration of Lead in a soil can be measured using an Inductively Coupled Plasma Mass Spectrometry (ICPMS) under laboratory conditions. The present study investigates the Lead concentration of contaminated abandoned riffle range located in Augusta County, Virginia. Soil samples were obtained using soil augurs from three locations randomly based on the severity of contamination. Location three, which was …

Grain Size And Vegetation As Controlling Variables Of Stream Channel Morphology, Grant Colip

Senior Honors Projects, 2010-2019

Streams are one of the major driving forces that shape the landscapes in the Shenandoah Valley of Virginia and the eastern United States as a whole, and they serve an important role in transporting both water and sediment to the Atlantic Ocean. However, streams are often modified for human use, thus altering their natural equilibrium. These alterations have frequently led to the degradation of channel stability as well as damage to property and infrastructure. A better understanding of how both grain size (D₅₀) and vegetation impact stream sinuosity (S) is needed to analyze the prevalence of channel degradation …

Soil Capability Assessment For Expanding Irrigated Agriculture In The Irwin Focus Area And Surrounding Lands, Edward (Ted) Arnold Griffin, Angela Stuart-Street, Peter Tille

Resource management technical reports

The Midlands groundwater and land assessment is a $4.7 million Water for Food project using Royalties for Regions funding. It is seeking to confirm groundwater availability in focus areas that may form precincts of 2000–3000ha suitable for intensive irrigated horticulture. Irwin is one of these.

The Department of Water identified the Irwin focus area for investigation for irrigated agriculture potential. It covers almost 7000ha to the east of Dongara in the Mid West region of Western Australia.

This report provides the land assessment for the Irwin area. We expanded the investigation to include land outside of the focus area because …

Partitioned By Process: Measuring Post-Fire Debris Flow And Rill Erosion With Structure From Motion, Nicholas Ellett

Boise State University Theses and Dissertations

In mountainous regions burned by wildfires, profound changes in soil characteristics and combustion of vegetation increase hillslope and channel erosion during storm events. Reduced infiltration and abundant loose sediment produce large post-fire erosional events which endanger human lives and infrastructure and contribute significantly to long-term erosion rates. While the influence of fire in increasing erosion has long been recognized, quantifying volumes and sources of eroded material from burned landscapes is difficult. Pre-erosion high-resolution topographic data (e.g. lidar) are often not available in burned areas and determining specific contributions from post-fire hillslope and channel erosion is challenging. Multiple erosional processes mobilize …

Reconstructing Coastal Sediment Budgets From Beach‐ And Foredune‐Ridge Morphology: A Coupled Field And Modeling Approach, Dj Ciarletta, Jl Shawler, C Tenebruso, Christopher J. Hein, J Lorenzo‐Trueba

VIMS Articles

Preserved beach and foredune ridges may serve as proxies for coastal change, reflecting alterations in sea level, wave energy, or past sediment fluxes. In particular, time‐varying shoreface sediment budgets have been inferred from the relative size of foredune ridges through application of radiocarbon and optically stimulated luminescence dating to these systems over the last decades. However, geochronological control requires extensive field investigation and analysis. Purely field‐based studies might also overlook relationships between the mechanics of sediment delivery to the shoreface and foredune ridges, missing insights about sensitivity to changes in sediment budget. We therefore propose a simple geomorphic model of …

Detecting Coastal Marsh Change From Aerial Imagery Using Spectral And Textural Methods: Pascagoula River Estuary, Mississippi, 1955-2014, Margaret Claire Bell Waldron

Master's Theses

As sea level rise accelerates, coastal marsh ecosystems are increasingly vulnerable. Vertical accretion rates must exceed or keep pace with rates of sea level rise to prevent transition to open water or inland migration of marsh vegetation. While some marsh systems along the northern Gulf of Mexico coast have remained stable, others, e.g., the marshes of the Louisiana Gulf Coast, have experienced high rates of conversion to open water. This study examined the historical extent of intertidal marsh at the mouth of the Pascagoula River in Jackson County, Mississippi to determine whether marsh extent changed during the period 1955-2014 and …

Reconstructing Barrier Island Behavior From Overstepped Deposits And Relict Onshore Morphology : Modeling And Field Approaches, Daniel James Ciarletta

Theses, Dissertations and Culminating Projects

Barrier Islands comprise 10% of the Earth’s shorelines, fringing every continent except Antarctica. Despite their ubiquity, much about the medium to long-term evolution of these coastal systems remain poorly understood, mostly due to the destruction of the geologic record as barriers migrate landward under the influence of rising sea level. Even where modern barriers and related strandplain systems have prograded and regressed, leaving evidence of their former geometries in the form of relict shorelines, field investigations often require intensive labor and time commitments to interpret past evolution. In this work, several investigations are undertaken to use novel numerical modeling techniques …

Geochemical Analysis Of Mississippian Cherts And Devonian-Mississippian Novaculites, Southern Midcontinent Region, Julie Mary Cains

Graduate Theses and Dissertations

This study uses trace elements and radiogenic isotopes (Pb, Sr, and Nd) to investigate the origin and mode of formation for the siliceous deposits in the Lower Mississippian Boone Formation and the Devonian-Mississippian Arkansas Novaculite in the southern midcontinent. Mississippi Valley-type Pb-Zn ore deposits in the Tri-State District and the Northern Arkansas District were deposited by hydrothermal fluids, and highly radiogenic Pb isotope ratios suggest a genetic relationship between the Boone Formation chert (206Pb/204Pb ~ 21.59, 207Pb/204Pb ~ 15.87, 208Pb/204Pb ~ 40.10) and the MVT ores. Due to the very low concentration of Pb in the Boone chert (~2 ppm) …

Fun In A Kansas Salt Mine, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Most people probably do not know that salt deposits hundreds of feet thick lie buried beneath large parts of western Kansas, western Oklahoma and a small part of the northeastern Texas Panhandle. Native Americans and early European explorers found that where the salt deposits came near the land surface (for, example north of Hutchinson, Kansas) salt is dissolved by ground water and increases the salinity of rivers, streams, springs and ponds. This salty water was used as a salt source by these peoples. The Hutchinson Salt, a 275 million-year-old Middle Permian deposit, was discovered in an exploratory drill hole in …

Assessing The Habitability Of Mars Using Impact Crater Statistics, Emily N. Shaver

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Because Mars lacks a global magnetic field or protective ozone layer, its surface is unshielded to harsh radiation from space. This ionizing radiation breaks down any organic components in the soil at the martian surface on timescales of tens to hundreds of millions years (10–100 Ma). In planetary geology, we use the density of impact craters as a proxy for time: older surfaces tend to accumulate more craters. Using impact craters, we can assess the exposure age and therefore organic preservation potential of the Martian surface from orbit.

The goal of this ongoing project is to better understand exposure ages …

Index

Bulletin of the University of Nebraska State Museum

No abstract provided.

Anthropogenic Controls On Overwash Deposition: Evidence And Consequences, Laura Rogers, Laura Moore, Evan Goldstein, Christopher Hein, Jorge Lorenzo Trueba, Andrew Ashton

Jorge Lorenzo-Trueba

Accelerated sea level rise and the potential for an increase in frequency of the most intense hurricanes due to climate change threaten the vitality and habitability of barrier islands by lowering their relative elevation and altering frequency of overwash. High-density development may further increase island vulnerability by restricting delivery of overwash to the subaerial island. We analyzed pre-Hurricane Sandy and post-Hurricane Sandy (2012) lidar surveys of the New Jersey coast to assess human influence on barrier overwash, comparing natural environments to two developed environments (commercial and residential) using shore-perpendicular topographic profiles. The volumes of overwash delivered to residential and commercial …

Natural And Human-Induced Variability In Barrier-Island Response To Sea Level Rise, Jennifer Miselis, Jorge Lorenzo Trueba

Jorge Lorenzo-Trueba

Storm-driven sediment fluxes onto and behind barrier islands help coastal barrier systems keep pace with sea level rise (SLR). Understanding what controls cross-shore sediment flux magnitudes is critical for making accurate forecasts of barrier response to increased SLR rates. Here, using an existing morphodynamic model for barrier island evolution, observations are used to constrain model parameters and explore potential variability in future barrier behavior. Using modeled drowning outcomes as a proxy for vulnerability to SLR, 0%, 28%, and 100% of the barrier is vulnerable to SLR rates of 4, 7, and 10 mm/yr, respectively. When only overwash fluxes are increased …

Exploring The Role Of Organic Matter Accumulation On Delta Evolution, Jorge Lorenzo Trueba, Vaughan Voller, Chris Paola, Robert Twilley, Azure Bevington

Jorge Lorenzo-Trueba

We explore the role of plant matter accumulation in the sediment column in determining the response of fluvial-deltas to base-level rise and simple subsidence profiles. Making the assumption that delta building processes operate to preserve the geometry of the delta plain, we model organic sedimentation in terms of the plant matter accumulation and accommodation (space made for sediment deposition) rates. A spatial integration of the organic sedimentation, added to the known river sediment input, leads to a model of delta evolution that estimates the fraction of organic sediments preserved in the delta. The model predicts that the maximum organic fraction …

Rollover, Drowning, And Discontinuous Retreat: Distinct Modes Of Barrier Response To Sea-Level Rise Arising From A Simple Morphodynamic Model, Jorge Lorenzo Trueba, Andrew Dale Ashton

Jorge Lorenzo-Trueba

We construct a simple morphodynamic model to investigate the long-term dynamic evolution of a coastal barrier system experiencing sea-level rise. Using a simplified barrier geometry, the model includes a dynamic shoreface profile that can be out of equilibrium and explicitly treats barrier sediment overwash as a flux. With barrier behavior primarily controlled by the maximum potential overwash flux and the rate of shoreface response, the modeled barrier system demonstrates four primary behaviors: height drowning, width drowning, constant landward retreat, and a periodic retreat. Height drowning occurs when overwash fluxes are insufficient to maintain the landward migration rate required to keep …

Sediment Transport And Channel Morphology Of A Natural And A Leveed Alluvial River, Bo Wang

LSU Master's Theses

Alluvial rivers are shaped by interactions of flow and sediment transport. Their lower reaches to the world’s oceans are highly dynamic, often presenting engineering and management challenges. This thesis research aimed to investigate channel dynamics and sediment transport in a natural river and a highly engineered river in South Louisiana, in order to gain much-needed science information for helping develop sustainable practices in river engineering, sediment management, and coastal restoration and protection. Especially, the thesis research examined (1) riverbed deformation from bank to bank in the final 500-km reach of the Mississippi River, (2) bed material transport at the Mississippi-Atchafalaya …

Assessing Paleo-Coastal Caves Evolution And Sea Level Changes In Mallorca: Results From Radiometric Dating Of Speleothems, Giuseppe Lucia

USF Tampa Graduate Theses and Dissertations

Sea level affects the littoral morphology and structure in different ways. In coastal karst basins, dissolutional and depositional processes are strictly related to sea level variation. A great variety of karst-related geomorphological features and cave deposits exist above, below, and at sea level, and are extremely useful to study past changes of relative sea level. Within these, vadose speleothems such as flowstones and stalagmite, can document unequivocal maximum sea level constraints as well as record phreatic phases of sea level rise. Here we present a series of geochronological data from the eastern Mallorca and show the implication of relative sea …