Hydraulic Engineering Commons^™

Importance Of Snowmelt On Soil Nitrate Leaching To Groundwater – A Model Study, Sahila Beegum, Arindam Malakar, Chittaranjan Ray, Daniel D. Snow

Nebraska Water Center: Faculty Publications

The movement of nitrate to surface water bodies during snow accumulation and melting has been extensively studied, but there are only limited studies on the influence of snow processes on nitrate leaching to groundwater. The present study investigated the impact of snow processes on nitrate leaching to groundwater based on a simulation modeling approach using HYDRUS-1D. HYDRUS-1D model has a temperature threshold-based snow model in addition to water, solute, and heat simulation components. The snow component in HYDRUS-1D was previously not applied to snow simulation studies since the method does not consider a detailed physical and process-based representation of snow …

Time Domain Reflectometry Waveform Interpretation With Convolutional Neural Networks, Zhuangji Wang, Shan Hua, Dennis Timlin, Yuki Kojima, Songtao Lu, Wenguang Sun, David Fleisher, Robert Horton, Vangimalla R. Reddy, Katherine Tully

Nebraska Water Center: Faculty Publications

Interpreting time domain reflectometry (TDR) waveforms obtained in soils with non-uniform water content is an open question. We design a new TDR waveform interpretation model based on convolutional neural networks (CNNs) that can reveal the spatial variations of soil relative permittivity and water content along a TDR sensor. The proposed model, namely TDR-CNN, is constructed with three modules. First, the geometrical features of the TDR waveforms are extracted with a simplified version of VGG16 network. Second, the reflection positions in a TDR waveform are traced using a 1D version of the region proposal network. Finally, the soil relative permittivity values …

Globally Scalable Approach To Estimate Net Ecosystem Exchange Based On Remote Sensing, Meteorological Data, And Direct Measurements Of Eddy Covariance Sites, Ruslan Zhuravlev, Andrey Dara, André Luís Diniz Dos Santos, Oleg Demidov, George Burba

Daugherty Water for Food Global Institute: Faculty Publications

Despite a rapid development of Nature-Based Solutions (NBS) for carbon removal in recent years, the methods for evaluating NBS still have certain gaps. We propose an approach based on a combination of remote sensing data and meteorological variables to reconstruct the spatiotemporal variation of net ecosystem exchange from eddy-covariance stations. A Lagrangian particle dispersion model was used for upscaling satellite images and flux towers. We trained data-driven models based on kernel methods separately for each selected land-cover class. The results suggest that the proposed approach to quantifying carbon exchange on a medium-to-large scale by blending eddy covariance flux data with …

Role Of Social Determinants Of Health In Differential Respiratory Exposure And Health Outcomes Among Children, Jagadeesh Puvvula, Jill A. Poole, Yeongjin Gwon, Eleanor G. Rogan, Jesse E. Bell

Daugherty Water for Food Global Institute: Faculty Publications

Background Attributes defining the Social Determinants of Health (SDoH) are associated with disproportionate exposures to environmental hazards and differential health outcomes among communities. The dynamics between SDoH, disproportionate environmental exposures, and differential health outcomes are often specific to micro-geographic areas.

Methods This study focused on children less than 20 years of age who lived in Douglas County, Nebraska, during 2016–2019. To assess the role of SDoH in differential exposures, we evaluated the association between SDoH metrics and criteria pollutant concentrations and the association between SDoH and pediatric asthma exacerbations to quantify the role of SDoH in differential pediatric asthma outcomes. …

Nebraska Water Center Annual Report 2023, Nebraska Water Center, Daugherty Water For Food Global Institute

Nebraska Water Center: Administrative Materials

The report's highlights updates including the water sciences laboratory, AltEn contamination monitoring and the Know your well project.

Implementation Of Digital Twins For Small Water Systems, Aidan Gill

Theses and Dissertations--Civil Engineering

The main objective of this thesis is to develop a working digital twin for a small water system in central Kentucky which will serve as a general format for other similar systems in the region wishing to implement digital twins for operator support. While the benefit of having a calibrated hydraulic and water quality model is widely understood, small distribution systems tend to not have the same financial and economic means to properly support these tools. Creation of a digital twin using this methodology provides a means for operators to predict pressure, flows, chlorine residuals, and total trihalomethane (TTHM) concentrations …

Labile Carbon And Soil Texture Control Nitrogen Transformation In Deep Vadose Zone, Lidong Li, Jordan Shields, Daniel D. Snow, Michael Kaiser, Arindam Malakar

Daugherty Water for Food Global Institute: Faculty Publications

Understanding transient nitrogen (N) storage and transformation in the deep vadose zone is critical for controlling groundwater contamination by nitrate. The occurrence of organic and inorganic forms of carbon (C) and nitrogen and their importance in the deep vadose zone is not well characterized due to difficulty in sampling and the limited number of studies. We sampled and characterized these pools beneath 27 croplands with different vadose zone thicknesses (6–45 m). We measured nitrate and ammonium in different depths for the 27 sites to evaluate inorganic N storage. We measured total Kjeldahl nitrogen (TKN), hot-water extractable organic carbon (EOC), soil …

Fluid Power Vehicle Challenge, Bryce Towne, Ethan Andrews, Carter Moore, Andrew Sobel

Williams Honors College, Honors Research Projects

The Fluid Power Vehicle Challenge is a competition held by the National Fluid Power Association (NFPA) that challenges students to create a hydraulically powered vehicle to compete in four different races over two days. The vehicle has to be fully powered by hydraulics, with human power (such as pedaling) being used to move the hydraulic fluid. Electronics and pneumatics can be used to control the flow of the hydraulic oil. Vehicles also must have an energy storage device to take advantage of regenerative braking. The final competition was at the Norgren facility in Colorado from April 12th to April 14th. …

Effects Of Coastal Structures On The Shoreline Change In Phan Thiet Bay, Vietnam, Hoai Thi Phuoc Pham

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis examined the effects of coastal structures on shoreline change in Phan Thiet Bay, Vietnam from 1988 to 2021. This thesis explored two key objectives; that were the investigation of historical shoreline changes and the effects of structures on shoreline based on the comparison of simulated shorelines with and without structures by using GENESIS model. Moreover, the SWAN model was used for simulating wave data which is an important input for the GENESIS model. From the shoreline evolution results, it was found that the land loss rate ranged from 0.9 to 8.7 ha/year in 1988 to 2016, while this …

Projections Of Drought Indices Under Climate Change In The Upper Chao Phraya River Basin, Pech Ponleu

Chulalongkorn University Theses and Dissertations (Chula ETD)

Climate change significantly impacts water resource management by intensifying the variability and frequency of extreme events like droughts. This study aims to understand drought processes and assess climate change impacts on drought in the Upper Chao Phraya River basin. The Standardized Precipitation Index (SPI) and Standardized Streamflow Index (SSI) of 3-, 6- and 12-month accumulation periods were estimated for historical from 1985 to 2014, near future (NF) from 2025 to 2054 and far future (FF) from 2070 to 2099 periods. Using GCMs from CMIP6 (MPI-ESM1-2-L, IPSL-CM6A-LR, and GFDL-CM4), bias-corrected via quantile mapping, we found good agreement with observed rainfall data. …

Projecting Low Flow Indices To Climate Change Using Cmip6 For The Upper Chao Phraya River Basin, Thailand, Chantharath Yos

Chulalongkorn University Theses and Dissertations (Chula ETD)

Human activities are impacting climate change. This is expected to cause a decrease in average runoff, leading to more frequent, longer, and more severe low-flow episodes at the catchment scale. Low-flow conditions can affect ecology, water quality, and water supply. The upper Chao Phraya River basin (CPRB) in Thailand has seen significant development and has experienced the effects of climate change. There is a critical question in the study of this region. Therefore, this study aims to develop low-flow indices, improve understanding of low-flow conditions, and assess the impacts of climate change on these indices. To assess the impact of …

การเคลื่อนที่ของตะกอนในแม่น้ำสายหลักของลุ่มน้ำเจ้าพระยาตอนบน, เมธาฤทธิ์ แนมสัย

Chulalongkorn University Theses and Dissertations (Chula ETD)

การวิจัยนี้มีวัตถุประสงค์เพื่อศึกษาการเคลื่อนที่ของตะกอน ในแม่น้ำสายหลักของลุ่มน้ำเจ้าพระยาตอนบน ประกอบด้วย แม่น้ำปิง วัง ยม และน่าน ในการศึกษาได้ใช้ข้อมูลอุทกวิทยาย้อนหลัง ตั้งแต่ปี 2464 ถึง 2562 และข้อมูลสำรวจการไหลของน้ำและตะกอนในปี 2561 และ 2562 การวิเคราะห์การเคลื่อนที่ของตะกอนในแม่น้ำแต่ละสายได้ใช้วิธีการทางสถิติทั่วไป วิธี Mann-Kendall (MK) และวิธีโค้งทับทวี (DMC) ผลการศึกษา พบว่า ปริมาณตะกอนรายปีเฉลี่ยที่สถานีอุทกวิทยาใกล้ทางออกลุ่มน้ำของแม่น้ำปิง (สถานี P.17) วัง (สถานี W.4A) ยม (สถานี Y.16) และน่าน (สถานี N.67) ประมาณ 0.82, 0.26, 0.35 และ 1.88 ล้านตัน/ปี ตามลำดับ โดยการเคลื่อนที่ของตะกอนในแม่น้ำทั้ง 4 สาย ส่วนใหญ่เคลื่อนที่ในลักษณะแขวนลอยเป็นหลัก ยกเว้นแม่น้ำปิงด้านท้ายน้ำของเขื่อนภูมิพลที่เคลื่อนที่เป็นตะกอนท้องน้ำ ผลการศึกษาความผันแปรในเชิงเวลาของปริมาณตะกอนรายปี พบว่า หลายสถานีมีแนวโน้มลดลง ได้แก่ สถานี P.1 ของแม่น้ำปิง สถานี W.16A, W.1C และ W.23 ของแม่น้ำวัง สถานี N.5A, N.7A, N.8A และ N.67 ของแม่น้ำน่าน และแม่น้ำเจ้าพระยา ที่สถานี C.2 ในทางกลับกันที่สถานี Y.1C และ Y.16 ของแม่น้ำยมกลับมีแนวโน้มเพิ่มขึ้น ส่วนผลการศึกษาความผันแปรของปริมาณตะกอนในเชิงตำแหน่ง แสดงให้เห็นว่า ปริมาณตะกอนรายปีเฉลี่ยเพิ่มขึ้นตามระยะทางจากต้นน้ำไปยังท้ายน้ำ อย่างไรก็ตามปริมาณตะกอนในแม่น้ำยมและแม่น้ำวังมีการลดลงในแม่น้ำตอนล่างใกล้ทางออกของลุ่มน้ำ ผลการศึกษายังพบว่าการก่อสร้างเขื่อนภูมิพล กิ่วลม แม่จาง กิ่วคอหมา และฝายแม่ยม ไม่ได้ส่งผลอย่างมีนัยสำคัญต่อปริมาณตะกอนในแม่น้ำใกล้ทางออกลุ่มน้ำของแม่น้ำปิง วัง และยม ในขณะที่ใกล้ทางออกลุ่มน้ำของแม่น้ำน่านมีปริมาณตะกอนเพิ่มขึ้นหลังจากการก่อสร้างเขื่อนสิริกิติ์ แต่ปริมาณตะกอนกลับลดลงหลังจากการก่อสร้างเขื่อนทดน้ำนเรศวรและเขื่อนแควน้อยบำรุงแดน นอกจากนี้ยังพบว่า ปริมาณตะกอนที่สถานี C.2 หลังจากการสร้างอาคารชลศาสตร์ขนาดใหญ่ทั้ง 8 แห่ง ลดลงเพียง 31 เปอร์เซ็นต์ของปริมาณตะกอนก่อนก่อสร้างเขื่อนภูมิพล …

Using Modflow To Assess Groundwater Storage Enhancement Via A Floodplain Infiltration Basin, Lindsay Henning

All Master's Theses

Delaying groundwater discharge into rivers until it is critically needed during baseflow conditions provides promise for lowering elevated stream temperatures and improving habitat for aquatic species. Increasing groundwater storage may accomplish this in locations where excess spring runoff can be captured and allowed to infiltrate into the subsurface for later beneficial use, a process known as Managed Aquifer Recharge (MAR). Here, MAR via an infiltration basin is considered at a site along the Teanaway River in central Washington State. The effects of simulated ephemeral ponds of sizes varying from 554 m³ to 2430 m³ (0.449 acre-feet to 1.97 …

Hydraulic Computations For Stepped Concrete Overlays Of Embankment Dams, Tony L. Wahl, Sherry L. Hunt, Kem C. Kadavy, Henry T. Falvey

Protections Conference

One method for rehabilitating and modernizing embankment dams is the addition of a concrete overlay that protects the embankment and allows floods to pass safely over the dam. Roller compacted concrete is commonly used, which makes it practical to use a stepped construction that also enhances energy dissipation. Analysis of flow conditions over such structures requires computation of aerated flow and its effects on flow depth, training wall design, and energy dissipation. This paper describes Spillway Pro, an energy-based water surface profile calculation tool for smooth spillway chutes (Wahl et al. 2019), recently improved to also analyze stepped chutes. The …

Earlier Snowmelt May Lead To Late Season Declines In Plant Productivity And Carbon Sequestration In Arctic Tundra Ecosystems, Donatella Zona, Peter M. Lafleur, Koen Hufkens, Barbara Bailey, Beniamino Gioli, George Burba, Jordan P. Goodrich, Anna K. Liljedahl, Eugénie S. Euskirchen, Jennifer D. Watts, Mary Farina, John S. Kimball, Martin Heimann, Mathias Göckede, Martijn Pallandt, Torben R. Christensen, Mikhail Mastepanov, Efrén López-Blanco, Marcin Jackowicz-Korczynski, Albertus J. Dolman, Luca Belelli Marchesini, Roisin Commane, Steven C. Wofsy, Charles E. Miller, David A. Lipson, Josh Hashemi, Kyle A. Arndt, Lars Kutzbach, David Holl, Julia Boike, Christian Wille, Torsten Sachs, Aram Kalhori, Xia Song

Daugherty Water for Food Global Institute: Faculty Publications

Arctic warming is affecting snow cover and soil hydrology, with consequences for carbon sequestration in tundra ecosystems. The scarcity of observations in the Arctic has limited our understanding of the impact of covarying environmental drivers on the carbon balance of tundra ecosystems. In this study, we address some of these uncertainties through a novel record of 119 site-years of summer data from eddy covariance towers representing dominant tundra vegetation types located on continuous permafrost in the Arctic. Here we found that earlier snowmelt was associated with more tundra net CO2 sequestration and higher gross primary productivity (GPP) only in June …

Erosion And Resuspension Of Cohesive Sediments In Coastal Louisiana, Laith Qasem Shamaileh

LSU New Orleans Theses and Dissertations

The research presented in this study is motivated by the need to improve the predictions of cohesive sediment erosion and subsequent transport. In addition, the knowledge of the geotechnical engineering soil properties related to the erosion of sediments in coastal Louisiana has broad implications as these properties are used in transport models guiding the current restoration efforts. The erosion measuring device used in the study is the Cheng-Han Tasi and Wilbert Lick Shaker. Previous studies have been conducted before using the Shaker, but challenges with the calibration of the shear stress hampered the resuspension results produced by the Shaker. Therefore, …

A Multi-Criteria Ranking System For Prioritizing Maintenance Of Levee Systems In Arkansas, Nguyen Danh Phan

Graduate Theses and Dissertations

There are 208,009 properties in Arkansas that have more than a 26% chance of being severely affected by flooding over the next 30 years, which represents 13% of all properties in the state. A levee system is designed to reduce the flooding risk for urban and rural communities; however, most of the state's levees have been significantly outdated or built with engineering standards less rigorous than current best practices. The Levee Safety Action Classification (LSAC), as recorded in the National Levee Database (NLD), communicates the risk associated with living behind a particular levee and assists local, state, and federal stakeholders …

The Living Breakwaters Pdr Efforts Econcrete Resource Analysis, Guianina Ferrari, Shervon Stephens, Calvin O. Walters Jr.

Publications and Research

On October 29, 2012, Superstorm Sandy impacted 443,000 people and caused nearly $19 billion (about $58 per person in the US) worth of damage within New York City. As part of the New York City infrastructure reparation plan, the Living Breakwaters project in Tottenville addressed coastal resilience, allocating $100M of public funds to a series of artificial breakwaters by the southwest coast of Staten Island. Each breakwater is constructed and designed to mitigate water flow in storm events. ECOncrete, a primary element of the breakwater, is a specialty cast cementitious product that is marine organism-friendly that encourages biocalcification and photosynthesis. …

Chapter 6: Hydraulic Grade Line (Hgl) And Energy Grade Line (Egl), Donald V. Chase

Open Educational Resource: Civil Engineering Course Notes

No abstract provided.

Population Health Metrics During The Early Stages Of The Covid-19 Pandemic: Correlative Pilot Study, Marie A. Severson, David A. Cassada, Victor C. Huber, Daniel D. Snow, Lisa M. Mcfadden

Nebraska Water Center: Faculty Publications

Background: COVID-19 has caused nearly 1 million deaths in the United States, not to mention job losses, business and school closures, stay-at-home orders, and mask mandates. Many people have suffered increased anxiety and depression since the pandemic began. Not only have mental health symptoms become more prevalent, but alcohol consumption has also increased during this time. Helplines offer important insight into both physical and mental wellness of a population by offering immediate, anonymous, cheap, and accessible resources for health and substance use disorders (SUD) that was unobstructed by many of the mandates of the pandemic. Further, the pandemic also …

Enrofloxacin And Sulfamethoxazole Sorption On Carbonized Leonardite: Kinetics, Isotherms, Influential Effects, And Antibacterial Activity Toward S. Aureus Atcc 25923, Chanat Chokejaroenrat, Chainarong Sakulthaew, Khomson Satchasataporn, Daniel D. Snow, Tarik E. Ali, Mohammed A. Assiri, Apichon Watcharenwong, Saksit Imman, Nopparat Suriyachai, Torpong Kreetachat

Nebraska Water Center: Faculty Publications

Excessive antibiotic use in veterinary applications has resulted in water contamination and potentially poses a serious threat to aquatic environments and human health. The objective of the current study was to quantify carbonized leonardite (cLND) adsorption capabilities to remove sulfamethoxazole (SMX)- and enrofloxacin (ENR)-contaminated water and to determine the microbial activity of ENR residuals on cLND following adsorption. The cLND samples prepared at 450^oC and 850^oC (cLND450 and cLND550, respectively) were evaluated for structural and physical characteristics and adsorption capabilities based on adsorption kinetics and isotherm studies. The low pyrolysis temperature of cLND resulted in a …

Permafrost Landscape History Shapes Fluvial Chemistry, Ecosystem Carbon Balance, And Potential Trajectories Of Future Change, Scott Zolkos, Suzanne E. Tank, Steven V. Kokelj, Robert G. Striegl, Sarah Shakil, Carolina Voigt, Oliver Sonnentag, William L. Quinton, Edward A.G. Schuur, Donatella Zona, Peter M. Lafleur, Ryan C. Sullivan, Masahito Ueyama, David Billesbach, David Cook, Elyn R. Humphreys, Philip Marsh

Daugherty Water for Food Global Institute: Faculty Publications

Intensifying permafrost thaw alters carbon cycling by mobilizing large amounts of terrestrial substrate into aquatic ecosystems. Yet, few studies have measured aquatic carbon fluxes and constrained drivers of ecosystem carbon balance across heterogeneous Arctic landscapes. Here, we characterized hydrochemical and landscape controls on fluvial carbon cycling, quantified fluvial carbon fluxes, and estimated fluvial contributions to ecosystem carbon balance across 33 watersheds in four ecoregions in the continuous permafrost zone of the western Canadian Arctic: unglaciated uplands, ice-rich moraine, and organic-rich lowlands and till plains. Major ions, stable isotopes, and carbon speciation and fluxes revealed patterns in carbon cycling across ecoregions …

Analysis Of Current And Future Flood Hazard In The Sacramento-San Joaquin Delta, Nicholas L. Mcguire

Master's Theses

The primary motivation of this study is to estimate the current and future flood hazard throughout the Sacramento-San Joaquin Delta in the context of sea-level rise. I also analyzed the effects of storm surge and river flow on extreme events to better understand how these events originate and vary spatially and in time. To address this goal, I combined digital water level records (primarily 1983-present) with archival data collected by the California Department of Water Resources (1929-1983) to reevaluate flood hazard in the Delta and investigate the possible sensitivity of the region different sea-level rise projections. Available archival records from …

Formation Of Oil Particle Aggregates And The Impact On The Fate Of Oil, Wen Ji

Dissertations

Spilled oil slicks are likely to break into droplets offshore due to wave energy. The fate and transport of such droplets are affected by suspended particles in local marine environment, through forming oil particle aggregates (OPAs). OPA formation is affected by various factors, including the properties of the particles and oil, the mixing energy and duration, etc. To investigate the impact of these factors, lab scale experiments are conducted by using seawater (both artificial and natural) and kaolinite and silica to simulate the formation of OPAs in baffled flasks. In the first experiment, 9 gm and 3 gm spherical silica …

Using 2d Hec-Ras Modeling With Vertical Feature Extraction To Inform Ecological Design In The Lower Atchafalaya River Basin, Louisiana, Colin Anderson

LSU Master's Theses

A 2D HEC-RAS model was created to demonstrate applications of hydraulic modeling for informing ecological design. This was done by comparing the hydrologic conditions of a baseline year (2010) to that of the environmental flow prescription from Kozak et al. (2016). The inundation results are relevant to hydraulic connectivity and cypress regeneration.

The hydraulic model was created by assimilating numerous data sources, refining the model with vertical feature (VF) extraction, and calibrating/validating the model. Several topo-bathymetric sources were combined to create the digital elevation model (DEM). Most importantly, this included bathymetry of the backswamp. Polylines of significant VFs in the …

Wind Tunnel Modeling Of Jack Rabbit Ii Mock Urban Environment Gas Concentration Measurements, Sami S. Fares

Graduate Theses and Dissertations

The 2015 Jack Rabbit (JR) II field trials were conducted to improve understanding of the denser-than-air dispersion of chlorine in an urban environment. The field study involved five large-scale, outdoor release trials of chlorine in a mock urban environment (MUE) at Dugway Proving Ground (DPG). Various instrumentation was deployed, including JazTM Ultraviolet-Visible (UV-Vis) point sensors capable of measuring gas-phase chlorine concentration throughout the mock urban array.

The Chemical Hazards Research Center (CHRC) was tasked by the Chemical Security Analysis Center (CSAC) with the Mock Urban Wind Tunnel (MUWT) program to study the 2015 JR II Trials at wind tunnel scale. …

An Investigation Of Emerging Technologies To Advance The Understanding Of Dynamics Between The Floodplain And Main Channel Due To Riparian Vegetation, Smriti Chaulagain

Civil Engineering ETDs

Riparian vegetation covers only about 0.4% of the land surface whereas rivers and streams cover about 0.3 to 0.56% but riparian vegetation still provides substantial ecosystem services including many that affect hydrodynamic processes. The ability to estimate the flow resistance caused by vegetation and the consequences for hydrodynamic processes has long been a vexing problem for engineers. Flow resistance is strongly influenced by local hydraulic conditions (water velocity and depth) and vegetation structures, and in turn, vegetation affects mass and momentum exchange processes. However, riparian vegetation conditions change continuously due to external stressors including climate change (e.g., extended drought in …

Tracing Geochemical Sources And Health Risk Assessment Of Uranium In Groundwater Of Arid Zone Of India, P. Pandit, Atul Saini, Sabarathinam Chidambaram, Vinod Kumar, Banjarani Panda, A. L. Ramanathan, Netrananda Sahu, A. K. Singh, Rohit Mehra

Nebraska Water Center: Faculty Publications

Water quality degradation and metal contamination in groundwater are serious concerns in an arid region with scanty water resources. This study aimed at evaluating the source of uranium (U) and potential health risk assessment in groundwater of the arid region of western Rajasthan and northern Gujarat. The probable source of vanadium (V) and fluorine (F) was also identified. U and trace metal concentration, along with physicochemical characteristics were determined for 265 groundwater samples collected from groundwater of duricrusts and palaeochannels of western Rajasthan and northern Gujarat. The U concentration ranged between 0.6 and 260 μg L⁻¹ with a mean …

Hydrodynamic Limitations To Mangrove Seedling Retention In Subtropical Estuaries, Kelly M. Kibler, Christian Pilato, Linda Walters, Melinda Donnelly, Jyotismita Taye

Flow-biota Interaction and Natural Infrastructure Design

Mangrove forest sustainability hinges upon propagule recruitment and seedling retention. This study evaluates biophysical limitations to mangrove seedling persistence by measuring anchoring force of two mangrove species (Rhizophora mangle and Avicennia germinans). Anchoring force was measured in 362 seedlings via lateral pull-tests administered in mangrove forests of two subtropical estuaries and in laboratory-based experiments. Removal mechanism varied with seedling age: newly-established seedlings failed due to root pull-out while seedlings older than 3 months failed by root breakage. Anchoring force of R. mangle seedlings was consistently and significantly greater than A. germinans (GLM: p = 0.002), however force to …

Development And Evaluation Of Seasonal, Continental-Scale Streamflow Forecasts, Elissa Marie Yeates

Theses and Dissertations

Methods of forecasting streamflow using atmospheric ensembles and hydrologic routing have greatly improved over the past decades. These forecasts anticipate the timing and magnitude of streamflow peaks, enabling early warning of floods. Recent advances in atmospheric modeling have enabled production of forecasts months ahead, which are less precise but give a useful sense of trends.

The purpose of this study is to produce and evaluate a seasonal streamflow forecast model using a Muskingum routing hydrologic model coupled with runoff from a land surface model, and atmospheric input from a medium-term atmospheric and precipitation model. To evaluate the skill of the …