Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

2019

Series

Environmental Engineering

Institution
Keyword
Publication
File Type

Articles 1 - 30 of 104

Full-Text Articles in Engineering

College Of Engineering Senior Design Competition Fall 2019, University Of Nevada, Las Vegas Dec 2019

College Of Engineering Senior Design Competition Fall 2019, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …


Energy & Carbon Neutral Nyc, Evan Banks, Elena Zimareva, Elena Malysheva Dec 2019

Energy & Carbon Neutral Nyc, Evan Banks, Elena Zimareva, Elena Malysheva

Publications and Research

In 2016, the world's leading countries signed the Paris Agreement which focused on reducing anthropogenic climate change on the planet. On May 2019, New York State and New York City declared its own ambitious goals aimed at decarbonizing the city and restricting the state’s energy use to relying completely on renewables.

Some of these goals specifically target infrastructure in the city since estimates cite buildings as accounting for nearly 70% of New York’s energy use. The main law of New York’s Climate Policy, Local Law 97, requires all buildings over 25,000 sq ft to reduce their CO2 footprint by 40% …


Thermodynamic Model Of Co2 Deposition In Cold Climates, Sandra K. S. Boetcher, Ted Von Hippel, Matthew J. Traum Dec 2019

Thermodynamic Model Of Co2 Deposition In Cold Climates, Sandra K. S. Boetcher, Ted Von Hippel, Matthew J. Traum

Publications

A thermodynamic model, borrowing ideas from psychrometric principles, of a cryogenic direct-air CO2-capture system utilizing a precooler is used to estimate the optimal CO2 removal fraction to minimize energy input per tonne of CO2. Energy costs to operate the system scale almost linearly with the temperature drop between the ingested air and the cryogenic desublimation temperature of CO2, driving siting to the coldest accessible locations. System performance in three Arctic/Antarctic regions where the proposed system can potentially be located is analyzed. Colder ambient temperatures provide colder system input air temperature yielding lower CO2 removal energy requirements. A case is also …


Study On Dye-Sensitized Solar Cells Based On Tio2 Composite Nanomaterials, Cuiping Kang, Muhammad Aqeel Ashraf, Yung-Tse Hung Dec 2019

Study On Dye-Sensitized Solar Cells Based On Tio2 Composite Nanomaterials, Cuiping Kang, Muhammad Aqeel Ashraf, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

With the continuous development of nanomaterials, how to improve the conversion efficiency of DSSCs has been the focus of scholars. Nano-TiO2 material is a wide bandgap semiconductor with a bandgap of 3.2eV. It exhibits good performance in dye adsorption, charge separation, electron transport, etc., and has good chemical stability and strong acid and alkali resistance. Therefore, it was always the material of choice for the preparation of photoanodes. In this paper, different thicknesses of TiO2 NRs barrier layers were prepared on FTO substrates by solvothermal method and two-step spin coating method, and their electrochemical and photoelectric properties were tested by …


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 …


Moving From Walkability? Evaluation Traditional And Merging Data Sources For Evaluating Changes In Campus-Generated Greenhouse Gas Emissions, Troy Kawahara, Bo Liu, Anurag Pande, Calvin Thigpen, Carole Turley Voulgaris Nov 2019

Moving From Walkability? Evaluation Traditional And Merging Data Sources For Evaluating Changes In Campus-Generated Greenhouse Gas Emissions, Troy Kawahara, Bo Liu, Anurag Pande, Calvin Thigpen, Carole Turley Voulgaris

Mineta Transportation Institute Publications

Universities are increasingly committing to reduce campus-generated greenhouse gas emissions, whether voluntarily or in response to a legal mandate. As an initial step to keeping these commitments, universities need an accounting of baseline greenhouse gas emissions levels and means of monitoring changes in campus-generated greenhouse gas emissions over time. Commute-generated greenhouse gas emissions from travel to and from campus by students and employees are among the most difficult to quantify. This report examines some of the challenges associated with estimating campus-generated greenhouse gas emissions and evaluates ways to address those challenges. The purpose of this study is to identify changes …


Nineteenth-Century Tides In The Gulf Of Maine And Implications For Secular Trends, Richard D. Ray, Stefan A. Talke Oct 2019

Nineteenth-Century Tides In The Gulf Of Maine And Implications For Secular Trends, Richard D. Ray, Stefan A. Talke

Civil and Environmental Engineering Faculty Publications and Presentations

Since the early twentieth century, the amplitudes of tidal constituents in the Gulf of Maine and Bay of Fundy display clear secular trends that are among the largest anywhere observed for a regional body of water. The M2 amplitude at Eastport, Maine, increased at a rate of 14.1 ± 1.2 cm per century until it temporarily dropped during 1980–1990, apparently in response to changes in the wider North Atlantic. Annual tidal analyses indicate M2 reached an all‐time high amplitude last year (2018). Here we report new estimates of tides derived from nineteenth century water‐level measurements found in the U.S. National …


Simulation Of The Impact Of Connected And Automated Vehicles At A Signalized Intersection, Hamad Bader Almobayedh, Deogratias Eustace, Philip Appiah-Kubi Oct 2019

Simulation Of The Impact Of Connected And Automated Vehicles At A Signalized Intersection, Hamad Bader Almobayedh, Deogratias Eustace, Philip Appiah-Kubi

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Intersections are locations with higher likelihood of crash occurences and sources of traffic congestion as they act as bottlenecks compared with other parts of the roadway networks. Consequently, connected and automated vehicles (CAVs) can help to improve the efficiency of the roadways by reducing traffic congestion and traffic delays. Since CAVs are expected to take control from drivers (human control) in making many important decisions, thus they are expected to minimize driver (human) errors in driving tasks. Therefore, CAVs potential benefits of eliminating driver error include an increase in safety (crash reduction), smooth vehicle flow to reduce emissions, and reduce …


Improving The Sustainability Of The Built Environment By Training Its Workforce In More Efficient And Greener Ways Of Designing And Constructing Through The Horizon2020 Bimcert Project, Barry Mcauley, Avril Behan Sep 2019

Improving The Sustainability Of The Built Environment By Training Its Workforce In More Efficient And Greener Ways Of Designing And Constructing Through The Horizon2020 Bimcert Project, Barry Mcauley, Avril Behan

Conference papers

The construction industry consumes up to 50% of mineral resources excavated from nature, generates about 33% of CO2 present in the atmosphere and is responsible for 40% of total global energy through both construction and operation of buildings. The realisation that current pervasive construction practices now face globalization, sustainability, and environmental concerns, as well as ever-changing legislation requirements and new skills needed for the information age has resulted in technologies such as Building Information Modelling (BIM) becoming a key enabler in navigating these barriers. To assist in overcoming these barriers, a number of funding initiatives have been put in place …


Centres Of Excellence And Roadmaps For Digital Transition: Lessons For Ireland’S Construction Industry, Barry Mcauley, Alan Hore, Roger West Sep 2019

Centres Of Excellence And Roadmaps For Digital Transition: Lessons For Ireland’S Construction Industry, Barry Mcauley, Alan Hore, Roger West

Conference papers

Like most sectors in today’s working world, construction businesses are challenged to work in an increasingly digitised world with sophisticated demands from intelligent clients. So much has been written about the inefficiencies of the construction industry, its fragmentation, lack of collaboration, low margins, adversarial pricing, poor productivity, financial fragility, lack of research and development, poor industry image and relatively weak use of digital solutions. The Irish government recognises the importance of digital innovation to address many of the challenges the construction industry faces. With recent high profile reports of escalating spend on signature public sector projects and weak productivity performance …


An Investigation Into Current Procurement Strategies That Promote Collaboration Through Early Contractor Involvement With Regards To Their Suitability For Irish Public Work Projects, Barry Mcauley, Frederic Lefebvre Sep 2019

An Investigation Into Current Procurement Strategies That Promote Collaboration Through Early Contractor Involvement With Regards To Their Suitability For Irish Public Work Projects, Barry Mcauley, Frederic Lefebvre

Conference papers

Previous research has established that multi-disciplinary collaboration will benefit a construction project throughout its lifecycle. While Lean Construction, Building Information Modelling (BIM), and Integrated Project Delivery (IPD) can all be viewed as separate processes which add independent value to a project, they are more effective when used in partnership with each other. In order to ensure the high levels of collaboration expected for these processes to work in unison, the early involvement of the Contractor is paramount. Early contractor involvement within the design process can ensure a more focused integrated project team, improvement of both constructability and cost certainty, as …


From Roadmap To Implementation: Lessons For Ireland’S Digital Construction Programme, Barry Mcauley, Alan Hore, Roger West Sep 2019

From Roadmap To Implementation: Lessons For Ireland’S Digital Construction Programme, Barry Mcauley, Alan Hore, Roger West

Conference papers

As part of their Future of Construction initiative in 2018 the World Economic Forum published an action plan to accelerate Building Information Modelling adoption. The WEF report highlighted actions that companies, industry organisations and governments are advised to implement to accelerate BIM adoption and better capitalise on delivering better project outcomes. According the authors of the report BIM is seen as the centrepiece of the construction industry’s digital transformation, however they acknowledged that BIM adoption globally remain slow. Anecdotal experience would suggest that BIM usage in Ireland is also very low and that a similar initiative or an adaptation of …


Delivering Energy Savings For The Supply Chain Through Building Information Modelling As A Result Of The Horizon 2020 Energy Bimcert Project, Barry Mcauley, Avril Behan Sep 2019

Delivering Energy Savings For The Supply Chain Through Building Information Modelling As A Result Of The Horizon 2020 Energy Bimcert Project, Barry Mcauley, Avril Behan

Conference papers

The global buildings sector is now responsible for 40% of final energy consumption as well as accounting for 33% of energy-related carbon dioxide emissions. This has resulted in a growing urgency to address energy and emissions from buildings and construction, to meet restrictive 2020 targets as specified by the European Union (EU). To achieve these targets a number of funding initiatives have been put in place through Horizon 2020 with a focus on BIM, due to it having the potential to rapidly produce energy outputs that enable design teams to analyse and compare the most cost-effective, energy-efficient options. However, despite …


Historical Changes In Lower Columbia River And Estuary Floods: A Numerical Study, Lumas Helaire, Stefan Talke, David A. Jay, Andrew Mahedy Sep 2019

Historical Changes In Lower Columbia River And Estuary Floods: A Numerical Study, Lumas Helaire, Stefan Talke, David A. Jay, Andrew Mahedy

Civil and Environmental Engineering Faculty Publications and Presentations

Over the past 150 years, the Lower Columbia River Estuary controlling depth has approximately doubled, the majority of historical wetlands and floodplain have been reclaimed, numerous infrastructure projects have altered and confined flow pathways, and significant natural and anthropogenic changes to the discharge hydrograph have occurred. To investigate the effect of these changes on tides, river slope, and flood water levels, we construct and validate numerical models that simulate flow over late nineteenth‐century and present‐day bathymetry. The models are validated using archival (1853–1877) and modern tide measurements throughout the Lower Columbia River Estuary and river stage measurements from the tidal …


Effects Of Nutrient Level And Growth Rate On Mutation And Conjugation Processes That Confer Antibiotic Resistance To E. Coli, Mohammadreza Shafieifini Aug 2019

Effects Of Nutrient Level And Growth Rate On Mutation And Conjugation Processes That Confer Antibiotic Resistance To E. Coli, Mohammadreza Shafieifini

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Antibiotic resistance genes (ARGs) may enter surface water with the discharge of treated wastewater. Conjugation is a main mechanism for the horizontal gene transfer of ARGs from wastewater microbiome to the microbiome indigenous to surface water. However, little is known about how environmental factors affect the conjugation process of ARGs.

In this thesis, an extensive research related to spreading antibiotic resistance genes in the environment is reported. The project investigated how environmental parameters may affect the rate of dissemination of ARGs and in what extent the resistance level of the population is changed after mutation and conjugation event. The chemostat …


Assessing The Impacts Of Super Storm Flooding In The Transportation Infrastructure – Case Study: San Antonio, Texas, Marcio Giacomoni, Francisco Olivera, Cesar Do Lago Aug 2019

Assessing The Impacts Of Super Storm Flooding In The Transportation Infrastructure – Case Study: San Antonio, Texas, Marcio Giacomoni, Francisco Olivera, Cesar Do Lago

Data

Corresponding data set for Tran-SET Project No. 18HSTSA02. Abstract of the final report is stated below for reference:

"Flooding are likely to increase worldwide due to climate change. Large storms, referred here as superstorms, defined as events with return period equal or larger than 100 years, can lead to an increase of property damages and loss of life. The ability to predict and plan for the impacts of superstorms on transportation infrastructure is key to mitigate future damages and losses. This study analyzed 51 combinations of future projections for representative concentration pathways (RCP) 4.5 and 8.5 scenarios, which were used …


Lifecycle Environmental Impact Of High-Speed Rail System In The I-45 Corridor, Raghava Kommalapati, Venkata Botlaguduru, Doeun Choe Aug 2019

Lifecycle Environmental Impact Of High-Speed Rail System In The I-45 Corridor, Raghava Kommalapati, Venkata Botlaguduru, Doeun Choe

Data

Corresponding data set for Tran-SET Project No. 18PPPVU01. Abstract of the final report is stated below for reference:

"The Houston-Dallas (I-45) corridor is the busiest route among 18 traffic corridors in Texas. The expected population growth and the surge in passenger mobility could result in a significant impact on the regional environment. This study uses a life cycle framework to estimate the net change in environmental impact with the development of a high speed rail system (HSR) along the I-45 corridor. The study follows ISO 14040 principles and standards of life cycle assessment and uses SimaPro 8.5® software and the …


Evaluation And Enhancement Of Carbon Sequestration Potential Of Existing Vegetation Along Roadsides, Vikram Kapoor, Jeffrey Hutchinson, Samer Dessouky Aug 2019

Evaluation And Enhancement Of Carbon Sequestration Potential Of Existing Vegetation Along Roadsides, Vikram Kapoor, Jeffrey Hutchinson, Samer Dessouky

Publications

The objectives of this study were to evaluate the vegetative composition and carbon sequestration potential of vegetation along a major roadway in Texas. Soil and vegetation were evaluated along IH-35 within Bexar County for composition and carbon content. Three 20 m transects were placed at each site and percent vegetative cover was estimated and above ground plant biomass, and soil was collected from three 0.25 m2 subplots along each transect. Plant and soil samples were analyzed for carbon content. Two non-native grasses, bermudagrass and King Ranch bluestem, were the dominant cover at all sites accounting for > 90% coverage at several …


Development Of Threshold Levels And A Climate-Sensitivity Model Of The Hydrological Regime Of The High-Altitude Catchment Of The Western Himalayas, Pakistan, Muhammad Saifullah, Shiyin Liu, Adnan Ahmad Tahir, Muhammad Zaman, Sajjad Ahmad, Muhammad Adnan, Dianyu Chen, Muhammad Ashraf, Asif Mehmood Jul 2019

Development Of Threshold Levels And A Climate-Sensitivity Model Of The Hydrological Regime Of The High-Altitude Catchment Of The Western Himalayas, Pakistan, Muhammad Saifullah, Shiyin Liu, Adnan Ahmad Tahir, Muhammad Zaman, Sajjad Ahmad, Muhammad Adnan, Dianyu Chen, Muhammad Ashraf, Asif Mehmood

Civil and Environmental Engineering and Construction Faculty Research

Water shortages in Pakistan are among the most severe in the world, and its water resources are decreasing significantly due to the prevailing hydro-meteorological conditions. We assessed variations in meteorological and hydrological variables using innovative trend analysis (ITA) and traditional trend analysis methods at a practical significance level, which is also of practical interest. We developed threshold levels of hydrological variables and developed a non-parametric climate-sensitivity model of the high-altitude catchment of the western Himalayas. The runoff of Zone I decreased, while the temperature increased and the precipitation increased significantly. In Zone II, the runoff and temperature increased but the …


Microbial Transport As Affected By Residue Cover And Manure Application Rate, Lisa M. Durso, John E. Gilley, Dave B. Marx, Chance A. Thayer, Brian L. Woodbury Jul 2019

Microbial Transport As Affected By Residue Cover And Manure Application Rate, Lisa M. Durso, John E. Gilley, Dave B. Marx, Chance A. Thayer, Brian L. Woodbury

Biological Systems Engineering: Papers and Publications

Manure is applied to cropland areas with varying surface cover to meet single- or multiple-year crop nutrient requirements. The objectives of this field study were to (1) examine microbial transport following land application of manure to sites with and without wheat residue, (2) compare microbial loads following land application to meet the 0, 1, 2, 4, and 8-year P-based requirements for corn, and (3) evaluate the effects of rainfall simulation run on microbial transport. Manure was added and incorporated by disking plots that were 0.75 m wide by 2.0 m long. Three 30 min simulated rainfall events, separated by 24 …


High‑Throughput Analysis Of Leaf Physiological And Chemical Traits With Vis–Nir–Swir Spectroscopy: A Case Study With A Maize Diversity Panel, Yufeng Ge, Abbas Atefi, Huichun Zhang, Chenyong Miao, Raghuprakash Kastoori Ramamurthy, Brandi Sigmon, Jinliang Yang, James C. Schnable Jun 2019

High‑Throughput Analysis Of Leaf Physiological And Chemical Traits With Vis–Nir–Swir Spectroscopy: A Case Study With A Maize Diversity Panel, Yufeng Ge, Abbas Atefi, Huichun Zhang, Chenyong Miao, Raghuprakash Kastoori Ramamurthy, Brandi Sigmon, Jinliang Yang, James C. Schnable

Biological Systems Engineering: Papers and Publications

Hyperspectral reflectance data in the visible, near infrared and shortwave infrared range (VIS–NIR– SWIR, 400–2500 nm) are commonly used to nondestructively measure plant leaf properties. We investigated the usefulness of VIS–NIR–SWIR as a high-throughput tool to measure six leaf properties of maize plants including chlorophyll content (CHL), leaf water content (LWC), specific leaf area (SLA), nitrogen (N), phosphorus (P), and potassium (K). This assessment was performed using the lines of the maize diversity panel. Data were collected from plants grown in greenhouse condition, as well as in the field under two nitrogen application regimes. Leaf-level hyperspectral data were collected with …


Development Of A Framework To Support The Effective Adoption Of Bim In The Public Sector: Lessons For Ireland, Shiyao Kuang, Alan Hore, Barry Mcauley, Roger West Jun 2019

Development Of A Framework To Support The Effective Adoption Of Bim In The Public Sector: Lessons For Ireland, Shiyao Kuang, Alan Hore, Barry Mcauley, Roger West

Conference papers

Building Information Modelling (BIM) has been formally adopted by many countries with the promise of creating greater economic, social and sustainability benefits. Several authors and institutions have presented alternative BIM policies and tactics which have been adopted by developed countries. However, there is evidence to indicate that BIM adoption theories are not well established and, in particular, the linkage between BIM public sector adoption strategy outcomes and their contribution to achieving Government policy objectives are underdeveloped. This paper will present the outcome of the first phase of a systematic literature review of published studies (including journal papers and noteworthy international …


Biomethane Production From Distillery Wastewater, Zachary Christman Jun 2019

Biomethane Production From Distillery Wastewater, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Distillery wastewater treatment is a great ecological problem, for example, India produces 2.7 billion liters of alcohol that results in 40 billion liters of wastewater. However, this material can be seen as a resource since 11 million cubic meters of biogas at 60% methane could be produced in addition to cleaning the water. The distillery has two options of what to do with the biogas. The first is to use the biogas to fuel the distillery making the production plant more energy efficient and removing some of the need to buy natural gas. The other is to upgrade the biogas …


A Spatially Enhanced Data‐Driven Multimodel To Improve Semiseasonal Groundwater Forecasts In The High Plains Aquifer, Usa, A. Amaranto, Francisco Munoz-Arriola, D. P. Solomatine, G. Corzo Jun 2019

A Spatially Enhanced Data‐Driven Multimodel To Improve Semiseasonal Groundwater Forecasts In The High Plains Aquifer, Usa, A. Amaranto, Francisco Munoz-Arriola, D. P. Solomatine, G. Corzo

Biological Systems Engineering: Papers and Publications

The aim of this paper is to improve semiseasonal forecast of groundwater availability in response to climate variables, surface water availability, groundwater level variations, and human water management using a two‐step data‐driven modeling approach. First, we implement an ensemble of artificial neural networks (ANNs) for the 300 wells across the High Plains aquifer (USA). The modeling framework includes a method to choose the most relevant input variables and time lags; an assessment of the effect of exogenous variables on the predictive capabilities of models; and the estimation of the forecast skill based on the Nash‐Sutcliffe efficiency (NSE) index, the normalized …


Environmental And Occupational Impacts From U.S. Beef Slaughtering Are Of Same Magnitude Of Beef Foodborne Illnesses On Human Health, Shaobin Li, Jeyamkondan Subbiah, Bruce Dvorak Jun 2019

Environmental And Occupational Impacts From U.S. Beef Slaughtering Are Of Same Magnitude Of Beef Foodborne Illnesses On Human Health, Shaobin Li, Jeyamkondan Subbiah, Bruce Dvorak

Biological Systems Engineering: Papers and Publications

Foodborne pathogens and occupational hazards are two primary safety concerns for U.S. beef slaughterhouses. The anthropogenic environmental impacts due to intensive resource use and pollution also exert threats to human health. Quantifying human health impacts from various sources remain a grand sustainability challenge for U.S. beef industry. We develop a framework to systematically estimate and compare human health impacts associated with U.S. beef foodborne illnesses from major pathogens and environmental impacts and occupational hazards from U.S. beef slaughtering on a common metric, disability-adjusted life year (DALY). Foodborne illnesses and occupational hazards are estimated by synthesizing published data and methodologies while …


Development Of An Rfid Tracking System For Coarse Sediment Transport In A Flume Setting, Peter Mahoney Jr. Jun 2019

Development Of An Rfid Tracking System For Coarse Sediment Transport In A Flume Setting, Peter Mahoney Jr.

ENGS 88 Honors Thesis (AB Students)

Development of an RFID Tracking System for Coarse Sediment Transport in a Flume Setting

Peter E. Mahoney

Professor Carl Renshaw

Understanding how sediment moves through a fluvial system has important implications for the study of river systems, sediment flux, and flood events. Over the past decade, RFID (radio frequency identification) technology has emerged as a useful method for tracking the movement and transport of coarse sediment clasts. This approach has been used to measure the transport of large clasts in mid-sized streams, ephemeral channels, and laboratory flume settings. However, this research utilized finite transport of sediment and focused on accurately …


Hydrodynamic Modeling Coupled With Long-Term Field Data Provide Evidence For Suppression Of Phytoplankton By Invasive Clams And Freshwater Exports In The San Francisco Estuary, Bruce G. Hammock Jun 2019

Hydrodynamic Modeling Coupled With Long-Term Field Data Provide Evidence For Suppression Of Phytoplankton By Invasive Clams And Freshwater Exports In The San Francisco Estuary, Bruce G. Hammock

Faculty Publications

The San Francisco Estuary (California, USA) had abundant pelagic fish in the late 1960s, but has few pelagic fish today. A primary cause for this decline in fish is thought to be a trophic cascade, triggered by declining phytoplankton. Here, we describe the changes in pelagic community structure of the San Francisco Estuary. Then, we examine whether changes in hydrodynamics due to freshwater exports, which increased exponentially beginning in 1967, in addition to the 1986 invasion by the clam Potamocorbula amurensis, explain the phytoplankton loss. Hydrodynamic variables were reconstructed back to 1956 using statistical models fit to, and cross-validated against, …


Next-Generation Rainfall Idf Curves For The Virginian Drainage Area Of Chesapeake Bay, Xixi Wang, Xiaomin Yang, Zhaoyi Cai Jun 2019

Next-Generation Rainfall Idf Curves For The Virginian Drainage Area Of Chesapeake Bay, Xixi Wang, Xiaomin Yang, Zhaoyi Cai

Civil & Environmental Engineering Faculty Publications

Probability-based intensity-duration-frequency IDF curves are needed but currently lacking for Department of Defense DoD to construct and manage its infrastructure in changing climate. The objectives of this project were to 1 develop an innovative approach for considering rainfall non-stationarity in developing such IDF curves and 2 apply this approach to the state of Virginia. In this regard, the observed data on 15-min rainfall at 57 gauges and the precipitations projected by twelve pairs of Regional Climate Model RCM and Global Circulation Model GCM were used. For a given gauge or watershed, in terms of fitting the empirical exceedance probabilities, a …


Mascoma River Greenway Extension, Isalys Quiñones May 2019

Mascoma River Greenway Extension, Isalys Quiñones

ENGS 86 Independent Projects (AB Students)

In July of 2018, the Mascoma River Greenway (MRG), a 2.2-mile rail trail extending from Downtown Lebanon, NH to Glen Road in West Lebanon, NH, was completed with the help of the MRG Coalition, the Friends of the Northern Rail Trail, Lebanon Recreation and Parks, and members of the City of Lebanon. Initially, this trail was proposed to extend from Downtown Lebanon to Downtown West Lebanon and White River Junction (WRJ). With pushback from the State of New Hampshire to lease the City of Lebanon recreational usage to the New Hampshire State Department of Transportation (NHDOT) owned rail corridor, the …


Development Of Digital Bathymetry Maps For Lakes Azuei And Enriquillo Using Sonar And Remote Sensing Techniques, Michael Piasecki, Mahrokh Moknatian, Fred Moshary, Jorge Gonzalez May 2019

Development Of Digital Bathymetry Maps For Lakes Azuei And Enriquillo Using Sonar And Remote Sensing Techniques, Michael Piasecki, Mahrokh Moknatian, Fred Moshary, Jorge Gonzalez

Publications and Research

This article presents an improved algorithm for optimization and development of a digital bathymetric model (DBM) for Lake Azuei (LA) (Haiti) and Lake Enriquillo (LE) (Dominican Republic) using the ANUDEM method. Both sonar data and contour lines of the lakes’ layout extracted using Landsat imagery were compiled for bathymetry development. We show that the performance of the ANUDEM method was strongly dependent on the density and irregularity of the spatial distribution of the data. Changing the resolution of the output grids and deriving auxiliary topographically corrected contours improved the ANUDEM performance and minimized the systematic errors of the method. Statistical …