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Full-Text Articles in Physical Sciences and Mathematics

Studying The South Lake Whatcom Fire, Lillian Buck Oct 2023

Studying The South Lake Whatcom Fire, Lillian Buck

WWU Honors College Senior Projects

This study investigates the ecological consequences of the South Lake Whatcom Fire, which occurred in August 2023, focusing on soil health and water quality. Lake Whatcom, historically shaped by indigenous settlements and 19th-century logging and mining activities, is a critical water source for Bellingham residents. The fire, sparked by lightning, was managed with hand-dug lines, and contained by September 2023. Soil analysis revealed a significant reduction in the organic matter/duff layer depth in burned areas compared to unburned sections, highlighting potential challenges for soil recovery and ecosystem health. Erosion concerns were raised, emphasizing the need for post-fire management strategies. This …


Effects Of Salix Psammophila On Groundwater Recharge In A Semiarid Area Of North China, Lizhu Hou, Jingdong Gao, Bill X. Hu, Xixi Wang Jan 2023

Effects Of Salix Psammophila On Groundwater Recharge In A Semiarid Area Of North China, Lizhu Hou, Jingdong Gao, Bill X. Hu, Xixi Wang

Civil & Environmental Engineering Faculty Publications

Study region: The semiarid Mu Us Sandy Land (MUSL) was selected for this study. It is in the farming-pastoral ecotone of north China and functions as an eco-environmental barrier.

Study focus: Afforestation can mitigate desertification and soil erosion by improving hydrologic condition, which is particularly true for semiarid and arid regions. However, little is known about the quantitative response of hydrologic improvement to afforestation level that can be measured by leaf area index (LAI). The objective was to setup and use a physically-based model to quantitatively assess the dynamics of water fluxes from Salix psammophila afforestation in the MUSL.

New …


Response To Comments For Butte Priority Soils Operable Unit (Bpsou) Draft Final Street And Snow Management Plan (Received December 15, 2021), Mike Mcanulty Jul 2022

Response To Comments For Butte Priority Soils Operable Unit (Bpsou) Draft Final Street And Snow Management Plan (Received December 15, 2021), Mike Mcanulty

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Soil Health, Laszlo Meredith Jan 2022

Soil Health, Laszlo Meredith

Natural Sciences Student Research Presentations

No abstract provided.


The Role Of Traditional Knowledge In Coastal Adaptation Priorities: The Pamunkey Indian Reservation, Nicole S. Hutton, Thomas R. Allen Dec 2020

The Role Of Traditional Knowledge In Coastal Adaptation Priorities: The Pamunkey Indian Reservation, Nicole S. Hutton, Thomas R. Allen

Political Science & Geography Faculty Publications

Coastal reservations are increasingly vulnerable to hazards exacerbated by climate change. Resources for restoration projects are limited. Storm surge, storms, tidal flooding, and erosion endanger artifacts and limit livelihoods of tribes in coastal Virginia. GIS offers a platform to increase communication between scientists, planners, and indigenous groups. The Pamunkey Indian Tribe engaged in a participatory mapping exercise to assess the role of traditional ecological knowledge (TEK) in coastal management decision-making and its capacity to address flooding. Priorities and strategies were spatially referenced using maps of potential sea level rise for 2040, 2060, and 2080, input into a resilience matrix to …


What Drives Property Owners To Modify Their Shorelines? A Case Study Of Gloucester County, Virginia, Sarah Stafford, Amanda Guthrie Sep 2020

What Drives Property Owners To Modify Their Shorelines? A Case Study Of Gloucester County, Virginia, Sarah Stafford, Amanda Guthrie

VIMS Articles

This analysis uses data from a survey of shoreline property owners combined with data on shoreline modification permits to examine whether and how property owners modify their estuarine shorelines. We find that shoreline armoring is very popular among property owners that choose to modify their shoreline. While living shorelines are less common, applications for them are increasing both in absolute numbers and as a percentage of all shoreline modification requests. A number of different issues factor into the shoreline modification decision including effectiveness, cost, aesthetics, and property values. More valuable parcels are more likely to be modified, as are parcels …


High-Frequency Data Reveal Differential Dissolved And Suspended Solids Behavior From A Mixed Restored Prairie And Agricultural Catchment, Andrew Miller, Ashlee L. Dere, Tracy Coleman Aug 2020

High-Frequency Data Reveal Differential Dissolved And Suspended Solids Behavior From A Mixed Restored Prairie And Agricultural Catchment, Andrew Miller, Ashlee L. Dere, Tracy Coleman

Chemistry Faculty Publications

Quantifying temporal variability and fluxes within hydrologic catchments is critical to understanding the underlying chemical and physical processes leading to material transport. Measuring variability and fluxes requires sampling at time scales similar to the time scale of process occurrence. This demand has led to the development of automated sampling systems designed to sample at high frequencies, on the order of minutes. While widely deployed in a variety of systems, we installed two high-frequency sampling devices in a single drainage comprised of restored prairie and agricultural land uses in temperate Eastern Nebraska. The sampling systems determined flow rate, conductivity, and turbidity …


Impact Of Streambank Stabilization On Sediment Deposition And Erosion In Central Nebraska Streams, Matthew Russell Apr 2020

Impact Of Streambank Stabilization On Sediment Deposition And Erosion In Central Nebraska Streams, Matthew Russell

School of Natural Resources: Dissertations, Theses, and Student Research

Stabilization projects are increasingly used to mitigate the effects of anthropogenic streambank erosion, yet the effectiveness of these practices has been insufficiently monitored and assessed to date. Sound monitoring practices promote engineered effectiveness, in addition to allowing adjustments in implementation and maintenance to improve practices over time. However, current methods to quickly and efficiently quantify deposition and erosion within a stream continue to be costly and inefficient. Therefore, the objectives of this project were to 1) Measure streambank migration of three reaches at Cedar River in Nebraska, from 1993 to 2006 (pre-stabilization) and from 2006 to 2018 (post-stabilization) using aerial …


Seagrass Losses Since Mid‐20th Century Fuelled Co2 Emissions From Soil Carbon Stocks, Cristian Salinas, Carlos M. Duarte, Paul Lavery, Pere Masque´, Ariane Arias-Ortiz, Javier X. Leon, David Callaghan, Gary A. Kendrick, Oscar Serrano Jan 2020

Seagrass Losses Since Mid‐20th Century Fuelled Co2 Emissions From Soil Carbon Stocks, Cristian Salinas, Carlos M. Duarte, Paul Lavery, Pere Masque´, Ariane Arias-Ortiz, Javier X. Leon, David Callaghan, Gary A. Kendrick, Oscar Serrano

Research outputs 2014 to 2021

Seagrass meadows store globally significant organic carbon (Corg) stocks which, if disturbed, can lead to CO2 emissions, contributing to climate change. Eutrophication and thermal stress continue to be a major cause of seagrass decline worldwide, but the associated CO2 emissions remain poorly understood. This study presents comprehensive estimates of seagrass soil Corg erosion following eutrophication‐driven seagrass loss in Cockburn Sound (23 km2 between 1960s and 1990s) and identifies the main drivers. We estimate that shallow seagrass meadows ( < 5 m depth) had significantly higher Corg stocks in 50 cm thick soils (4.5 ± 0.7 kg Corg/m2) …


Seagrass Losses Since Mid-20th Century Fuelled Co2 Emissions From Soil Carbon Stocks [Dataset], Cristian Salinas, Carlos M. Duarte, Paul S. Lavery, Pere Masque, Ariane Arias-Ortiz, Javier Leon, David Callaghan, Gary A. Kendrick, Oscar Serrano Jan 2020

Seagrass Losses Since Mid-20th Century Fuelled Co2 Emissions From Soil Carbon Stocks [Dataset], Cristian Salinas, Carlos M. Duarte, Paul S. Lavery, Pere Masque, Ariane Arias-Ortiz, Javier Leon, David Callaghan, Gary A. Kendrick, Oscar Serrano

Research Datasets

The database compiles published data (in Salinas et al. 2020) on biogeochemical characteristics (density, organic carbon, stable carbon isotopes, sediment grain size) of cores from Posidonia australis and sinuosa soil in Cockburn Sound, Western Australia.

Enquiries about the dataset may be sent to Cristian Salinas: c.salinaszapata@ecu.edu.au


Defining Boat Wake Impacts On Shoreline Stability Toward Management And Policy Solutions, Donna Marie Bilkovic, Molly M. Mitchell, Jennifer Davis, Julie Herman, Elizabeth Andrews, Angela King, Pamela Mason, Navid Tahvildari, Jana Davis, Rachel L. Dixon Dec 2019

Defining Boat Wake Impacts On Shoreline Stability Toward Management And Policy Solutions, Donna Marie Bilkovic, Molly M. Mitchell, Jennifer Davis, Julie Herman, Elizabeth Andrews, Angela King, Pamela Mason, Navid Tahvildari, Jana Davis, Rachel L. Dixon

Civil & Environmental Engineering Faculty Publications

Coastal economies are often supported by activities that rely on commercial or recreational vessels to move people or goods, such as shipping, transportation, cruising, and fishing. Unintentionally, frequent or intense vessel traffic can contribute to erosion of coastlines; this can be particularly evident in sheltered systems where shoreline erosion should be minimal in the absence of boat waves. We reviewed the state of the science of known effects of boat waves on shoreline stability, examined data on erosion, turbidity, and shoreline armoring patterns for evidence of a response to boat waves in Chesapeake Bay, and reviewed existing management and policy …


Measuring Streambank Erosion: A Comparison Of Erosion Pins, Total Station, And Terrestrial Laser Scanner, Daniel T. L. Myers, Richard R. Rediske, James N. Mcnair Sep 2019

Measuring Streambank Erosion: A Comparison Of Erosion Pins, Total Station, And Terrestrial Laser Scanner, Daniel T. L. Myers, Richard R. Rediske, James N. Mcnair

Funded Articles

Streambank erosion is diffcult to quantify; models and field methods are needed to assess this important sediment source to streams. Our objectives were to (1) evaluate and compare three techniques for quantifying streambank erosion: erosion pins, total station, and laser scanning, (2) spatially assess streambank erosion rates in the Indian Mill Creek watershed of Michigan, USA, and (3) relate results with modeling of nonpoint source pollution. We found large absolute and relative errors between the different measurement techniques. However, we were unable to determine any statistically significant differences between techniques and only observed a correlation between total station and laser …


Living Shorelines: Barriers And Promotion: Accomack County, Va, Amy Belcher, Rhiannon Bezore, Michelle Covi, Wie Yusuf Sep 2019

Living Shorelines: Barriers And Promotion: Accomack County, Va, Amy Belcher, Rhiannon Bezore, Michelle Covi, Wie Yusuf

Presentations, Lectures, Posters, Reports

Living shorelines can offer shoreline protection for low energy shorelines as well as providing ecoservices such as purifying water, buffering against floods, and attracting wildlife. This report highlights key benefits, possible barriers and solutions, and ideas for their promotion. Recommendations for implementing living shorelines are included for Accomack County, Virginia to aid in increasing awareness and utilization of living shorelines.


Riparian Resilience In The Face Of Interacting Disturbances, Alexa S. Whipple May 2019

Riparian Resilience In The Face Of Interacting Disturbances, Alexa S. Whipple

2019 Symposium

Riparian systems of the dryland western United States provide critical ecosystem functions such as diverse habitat for numerous species, flood attenuation and essential water storage in water-limited environments. These systems have experienced long term disturbance from anthropogenic activities including the grazing of livestock in dryland riparian systems and near extirpation of a keystone riparian species, Castor canadensis (beaver). However, increasing frequency of large-scale wildfires and climate change driven weather is altering the severity and scale of riparian disturbance. Beaver restoration has been gaining use to address long term riparian disturbances, yet little is understood regarding the impact of restored beaver …


Long Reach Lane At Long Marsh, Harpswell, 2018 Post-Project Monitoring Report; Year 5 Of 5, Matthew Craig Mar 2019

Long Reach Lane At Long Marsh, Harpswell, 2018 Post-Project Monitoring Report; Year 5 Of 5, Matthew Craig

Publications

No abstract provided.


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 Feb 2019

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 …


Embracing Dynamic Design For Climate-Resilient Living Shorelines, Molly Mitchell, Donna M. Bilkovic Jan 2019

Embracing Dynamic Design For Climate-Resilient Living Shorelines, Molly Mitchell, Donna M. Bilkovic

VIMS Articles

As natural marshes are lost to erosion, sea level rise, and human activity, small created marshes, (sometimes with ancillary stabilization structures, and frequently called living shorelines) have gained interest as a replacement habitat; providing both shoreline stabilization and restoration of important ecological functions. These living shorelines enhance ecological function while reducing erosion through the use of marsh plants (Table 1). In all but the lowest energy settings, oyster reefs, low rock structures, or other stabilizing material are frequently used to enhance marsh establishment. Due to their ability to stabilize the shoreline with minimal impact to the ecology, living shorelines are …


The Tides They Are A-Changin': A Comprehensive Review Of Past And Future Nonastronomical Changes In Tides, Their Driving Mechanisms, And Future Implications, Ivan D. Haigh, Mark D. Pickering, J. A. Mattias Green, Brian K. Arbic, Arne Arns, Sönke Dangendorf, David F. Hill, Kevin Horsburgh, Tom Howard, Déborah Idier, David A. Jay, Leon Jänicke, Serena B. Lee, Malte Müller, Michael Schindelegger, Stefan A. Talke, Sophie-Berenice Wilmes, Philip L. Woodworth Jan 2019

The Tides They Are A-Changin': A Comprehensive Review Of Past And Future Nonastronomical Changes In Tides, Their Driving Mechanisms, And Future Implications, Ivan D. Haigh, Mark D. Pickering, J. A. Mattias Green, Brian K. Arbic, Arne Arns, Sönke Dangendorf, David F. Hill, Kevin Horsburgh, Tom Howard, Déborah Idier, David A. Jay, Leon Jänicke, Serena B. Lee, Malte Müller, Michael Schindelegger, Stefan A. Talke, Sophie-Berenice Wilmes, Philip L. Woodworth

CCPO Publications

Scientists and engineers have observed for some time that tidal amplitudes at many locations are shifting considerably due to nonastronomical factors. Here we review comprehensively these important changes in tidal properties, many of which remain poorly understood. Over long geological time scales, tectonic processes drive variations in basin size, depth, and shape and hence the resonant properties of ocean basins. On shorter geological time scales, changes in oceanic tidal properties are dominated by variations in water depth. A growing number of studies have identified widespread, sometimes regionally coherent, positive, and negative trends in tidal constituents and levels during the 19th, …


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 Dec 2018

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 …


Lithologic Controls On Focused Erosion And Intraplate Earthquakes In The Eastern Tennessee Seismic Zone, Sean F. Gallen, J. Ryan Thigpen Sep 2018

Lithologic Controls On Focused Erosion And Intraplate Earthquakes In The Eastern Tennessee Seismic Zone, Sean F. Gallen, J. Ryan Thigpen

Earth and Environmental Sciences Faculty Publications

We present a new geomorphic model for the intraplate eastern Tennessee seismic zone (ETSZ). Previous studies document that the Upper Tennessee drainage basin is in a transient state of adjustment to ~150 m of base level fall that occurred in the Late Miocene. Using quantitative geomorphology, we demonstrate that base level fall resulted in the erosion of ~3,500 km3 of highly erodibility rock in an ~70 km wide by ~350‐km‐long corridor in the Paleozoic fold‐thrust belt above the ETSZ. Models of modern incision rates show a NE‐SW trending swath of elevated erosion ~30 km southeast of the center of …


Erosion In Extruder Flows: Analytical And Numerical Study, Miron Kaufman, Petru S. Fodor Dec 2017

Erosion In Extruder Flows: Analytical And Numerical Study, Miron Kaufman, Petru S. Fodor

Physics Faculty Publications

© 2017 Author(s). We consider the erosion of particles (e.g. carbonblack agglomerates) advected by the polymeric flow in a single screw extruder. We assume a particle to be made of primary fragments bound together. In the erosion process a primary fragment breaks out of a given particle. Particles disperse because of the shear stresses imparted by the fluid. The time evolution of the numbers of particles of different sizes is described by the Bateman coupled differential equations developed a century ago to model radioactivity. Using the particle size distribution we compute an entropic fragmentation index which varies from 0 for …


Tracing Sediment Erosion In The Yangtze River Subaqueous Delta Using Magnetic Methods, Can Ge, Weiguo Zhang, Chenyin Dong, Feng Wang, Huan Feng, Jianguo Qu, Lizhong Yu Nov 2017

Tracing Sediment Erosion In The Yangtze River Subaqueous Delta Using Magnetic Methods, Can Ge, Weiguo Zhang, Chenyin Dong, Feng Wang, Huan Feng, Jianguo Qu, Lizhong Yu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

We assessed the usefulness of magnetic properties for tracing sediment erosion in a deltaic environment. Surface and core sediments from the Yangtze River subaqueous delta were subjected to magnetic, granulometric, geochemical, and radionuclide analyses. Based on magnetic properties and particle size, the surface sediments can be divided into three groups. Groups I and II have a similar particle size distribution and geochemical composition, but the former has higher values of magnetic susceptibility (χ) and saturation isothermal remanent magnetization (SIRM). We interpret Group I as consisting of modern sediments, while Group II represents previously buried sediments that have undergone significant reductive …


East African Weathering Dynamics Controlled By Vegetation-Climate Feedbacks, Sarah J. Ivory, Michael M. Mcglue, Geoffrey S. Ellis, Adam Boehlke, Anne-Marie Lézine, Annie Vincens, Andrew S. Cohen Sep 2017

East African Weathering Dynamics Controlled By Vegetation-Climate Feedbacks, Sarah J. Ivory, Michael M. Mcglue, Geoffrey S. Ellis, Adam Boehlke, Anne-Marie Lézine, Annie Vincens, Andrew S. Cohen

Earth and Environmental Sciences Faculty Publications

Tropical weathering has important linkages to global biogeochemistry and landscape evolution in the East African rift. We disentangle the influences of climate and terrestrial vegetation on chemical weathering intensity and erosion at Lake Malawi using a long sediment record. Fossil pollen, microcharcoal, particle size, and mineralogy data affirm that the detrital clays accumulating in deep water within the lake are controlled by feedbacks between climate and hinterland forest composition. Particle-size patterns are also best explained by vegetation, through feedbacks with lake levels, wildfires, and erosion. We develop a new source-to-sink framework that links lacustrine sedimentation to hinterland vegetation in tropical …


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 May 2017

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 …


Evidence Of Erosional Self-Channelization Of Pyroclastic Density Currents Revealed By Ground-Penetrating Radar Imaging At Mount St. Helens, Washington (Usa), Andrew C. Gase, Brittany D. Brand, John H. Bradford Mar 2017

Evidence Of Erosional Self-Channelization Of Pyroclastic Density Currents Revealed By Ground-Penetrating Radar Imaging At Mount St. Helens, Washington (Usa), Andrew C. Gase, Brittany D. Brand, John H. Bradford

Geosciences Faculty Publications and Presentations

The causes and effects of erosion are among the least understood aspects of pyroclastic density current (PDC) dynamics. Evidence is especially limited for erosional self-channelization, a process whereby PDCs erode a channel that confines the body of the eroding flow or subsequent flows. We use ground-penetrating radar imaging to trace a large PDC scour and fill from outcrop to its point of inception and discover a second, larger PDC scour and fill. The scours are among the largest PDC erosional features on record, at >200 m wide and at least 500 m long; estimated eroded volumes are on the order …


Effects Of Habitat Restoration On Soil Retention On Santa Rosa Island, Michael Perez, Kathryn Mceachern, Ken Niessen Jan 2017

Effects Of Habitat Restoration On Soil Retention On Santa Rosa Island, Michael Perez, Kathryn Mceachern, Ken Niessen

STAR Program Research Presentations

Ranching began on Santa Rosa Island in the 1840’s, consequently introducing nonnative megafauna that put novel selective grazing pressures on endemic plant species. Their movement patterns also altered substrate integrity as the land became denuded of any stabilizing vegetation. Dense groves of island oak (Q. tomentella) are known to aid in sediment deposition and retention. The groves also function to collect water during periods of intense fog common to the island. This experiment sought to determine whether sediment is being lost or deposited on a ridge in the middle of the island containing a grove of Q. tomentella …


Weathering And Erosion Of Fractured Bedrock Systems, Marina I. Lebedeva, Susan L. Brantley Jan 2017

Weathering And Erosion Of Fractured Bedrock Systems, Marina I. Lebedeva, Susan L. Brantley

United States Geological Survey: Staff Publications

We explore the contribution of fractures (joints) in controlling the rate of weathering advance for a low-porosity rock by using methods of homogenization to create averaged weathering equations. The rate of advance of the weathering front can be expressed as the same rate observed in non-fractured media (or in an individual block) divided by the volume fraction of nonfractured blocks in the fractured parent material. In the model, the parent has fractures that are filled with a more porous material that contains only inert or completely weathered material. The low-porosity rock weathers by reaction-transport processes. As observed in field systems, …


Irrigation Efficiency Of Santa Rosa Island Cloud Forest Restoration Project, Rebecca Bernard, Kathryn Mceachern, Ken Niessen Sep 2016

Irrigation Efficiency Of Santa Rosa Island Cloud Forest Restoration Project, Rebecca Bernard, Kathryn Mceachern, Ken Niessen

STAR Program Research Presentations

Beginning in the 1800s, sheep and cattle ranching have caused significant erosion and devegetation of Santa Rosa Island, Channel Islands National Park. In an effort to contain what little soil is left and rebuild the native chaparral, the Cloud Forest Restoration Project is testing erosion control structures such as wattles, leaf litter fences and silt dams. This summer a drip irrigation system was installed along with fog capturing fences to supply water to native plants transplanted near the erosion control structures. As the project has grown, more irrigation has been added to increase the area available for transplanting. This irrigation …


Estimated Grass Grazing Removal Rate In A Semiarid Eurasian Steppe Watershed As Influenced By Climate, Xixi Wang, Shohreh Pedram, Tingxi Liu, Ruizhong Gao, Fengling Li, Yanyun Luo Jan 2016

Estimated Grass Grazing Removal Rate In A Semiarid Eurasian Steppe Watershed As Influenced By Climate, Xixi Wang, Shohreh Pedram, Tingxi Liu, Ruizhong Gao, Fengling Li, Yanyun Luo

Civil & Environmental Engineering Faculty Publications

Grazing removal rate of grasses needs to be determined for various climate conditions to address eco-environmental concerns (e.g., desertification) related to steppe grassland degradation. The conventional approach, which requires survey data on animal species and heads as well as grass consumption per individual animal, is too costly and time-consuming to be applied at a watershed scale. The objective of this study was to present a new approach that can be used to estimate grazing removal rate with no requirement of animal-related data. The application of this new approach was demonstrated in a Eurasian semiarid typical-steppe watershed for an analysis period …


Large-Scale Mechanical Buckle Fold Development And The Initiation Of Tensile Fractures, Andreas Eckert, Peter Connolly, Xiaolong Liu Nov 2014

Large-Scale Mechanical Buckle Fold Development And The Initiation Of Tensile Fractures, Andreas Eckert, Peter Connolly, Xiaolong Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Tensile failure associated with buckle folding is commonly associated to the distribution of outer arc extension but has also been observed on fold limbs. This study investigates whether tensile stresses and associated failure can be explained by the process of buckling under realistic in situ stress conditions. A 2-D plane strain finite element modeling approach is used to study single-layer buckle folds with a Maxwell viscoelastic rheology. A variety of material parameters are considered and their influence on the initiation of tensile stresses during the various stages of deformation is analyzed. It is concluded that the buckling process determines the …