Fresh Water Studies Commons^™

Key Success Factors In Using The Lifting Method To Construct A Steel Bridge Pylon, Ming-Chao Su, Hui-Ping Tserng

Journal of Marine Science and Technology–Taiwan

Constructing the inclined steel pylon of cable-stayed bridges is challenging because of the pylon’s height, spatial limitations, and safety concerns. To address these challenges, this study developed a modular lifting method that can enhance the efficiency and precision of pylon construction. The proposed method involves using rotation jigs to temporarily assemble the pylon, horizontal positioning on temporary supports, and synchronized lifting through computer-controlled hydraulic systems. Field implementation on a large-span bridge project revealed that compared with the traditional method, the proposed method resulted in higher welding quality, lower risks associated with great-height operations, and a shorter on-site assembly time. The …

Deep Learning-Based Model For Automated Prediction Of Coastal Changes: A Robust Approach To Environmental Forecasting, Tsair-Fwu Lee, Chu-Ho Chang, Chin-Shiuh Shieh, Chih-Hsien Wu, Jen-Chung Shao, Chien-Liang Chiu

Journal of Marine Science and Technology–Taiwan

The coastline stands as a critical domain encompassing industry and the environment. The escalating global warming, leading to elevated sea levels and intensified wave-current interactions, has given rise to substantial coastal erosion. This predicament, in conjunction with excessive human development and Taiwan's coastal areas' extreme climatic impact, accentuates the perceptibility of coastal beach alterations. As a result, coastal erosion has emerged as a pressing issue necessitating resolution. Traditional methodologies for assessing coastline changes have conventionally relied on manual measurements. However, owing to the fluctuating distance of coastlines, influenced by tidal patterns, extended measurement processes over several months are susceptible to …

Hydrographic Influences On Seasonal Variations In Zooplankton Communities Of Taiwan Bank (Southern Taiwan Strait), Bor-Shyr Chen, Frank Paolo Jay B. Albarico, Mark Ariel D. Malto, Aiza D. Gabriel, Chiu-Wen Chen, Cheng-Di Dong

Journal of Marine Science and Technology–Taiwan

Understanding the factors that control ocean productivity is crucial in fisheries management. Taiwan Bank, located between the Taiwan Strait and the South China Sea, is a highly productive ecosystem due to upwelling events. The total zooplankton community (holozooplankton and merozooplankton), diversity, seasonal changes, and environmental drivers remain unexplored despite its productivity. This study evaluates the seasonal and vertical environmental dynamics in the Taiwan Bank and their impacts on the zooplankton community structure. We collected zooplankton and basic water parameters in March, July, and September 2017 at 5, 25, and 50 meters. We recorded significant seasonal changes in zooplankton composition and …

Model Performance For Predicting Trends And Analyzing The Impacts Of Sea Surface Temperature Changes In The Gulf Of Thailand, Tanatpong Udomchaipitak, Nathaphon Boonnam

Journal of Marine Science and Technology–Taiwan

This study focuses on assessing and improving the predictive performance of sea surface temperature (SST) in the Gulf of Thailand under unique environmental challenges. Data from the Hybrid Coordinate Ocean Model (HYCOM) were utilized, covering the period from July 1994 to June 2024 at depths ranging from 0 to 30 meters. After cleaning the data using the Interquartile Range (IQR) method, the processed dataset was tested using four models: Recurrent Neural Network (RNN) architectures, including Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU), as well as Convolutional Neural Networks (CNNs). Model performance was enhanced by tuning the parameters over …

Shifting Waters: A 41-Year Time-Series Analysis Of Surface Water Change In The Prairie Pothole Region, Madison Dejarlais

Electronic Theses and Dissertations

The Prairie Pothole Region (PRR) is a landscape defined by a dynamic surface water system, with wetlands, lakes, and rivers playing critical roles in supporting biodiversity, regulating floods, and maintaining hydrological balance. This study conducts a time-series analysis of surface water change in the PPR from 1984 to 2024, using remote sensing tools including Google Earth Engine, ArcGIS Pro, and ENVI. 41 annual surface water presence rasters were compiled into a cumulative dataset, allowing for both year-to-year comparisons and broader trend analysis. Results indicate that the presence of surface water in the PPR has not followed a simple linear trend. …

Dam It All: A Multi-Scalar Investigation Into The Ecological Role And Function Of Beaver Dams, Kenneth Larsen

Dissertations, Master's Theses and Master's Reports

The central theme of this dissertation is ecological scaling, which examines how small, localized features, such as beaver ponds, contribute to large-scale watershed processes and how different modeling approaches at various scales reveal distinct insights. Through a combination of probabilistic modeling and high-resolution empirical research, this work demonstrates that small ponded systems, particularly those created by beavers (Castor canadensis), serve as critical biogeochemical control points, whose contributions to sediment and nutrient dynamics have been historically underestimated.

In Chapter 1, I contextualize this research within the broader fields of freshwater ecology, watershed modeling, and ecological restoration. I introduce the …

Great Lakes And Its Regional Climate In The Future, Miraj Bhakta Kayastha

Dissertations, Master's Theses and Master's Reports

The overarching objective of this dissertation is to enhance our predictive understanding of the Great Lakes regional climate by utilizing advanced modeling techniques and provide comprehensive insights into the future of the Great Lakes. This dissertation focuses on four areas pertinent to the future of the Great Lakes hydroclimate and extreme events, beginning with the derivation of robust water level projections for the Great Lakes in Chapter 2. Using a regional climate modeling system with a two-way coupled three-dimensional (3D) hydrodynamic lake and ice model for the Great lakes, we analyze long-term future changes in the over-lake precipitation, lake evaporation, …

Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones

Graduate Theses/Dissertations

Karst landscapes are abundant in Missouri, with features such as caves, springs, and sinkholes that form through the dissolution of limestone. Leith Creek is a small stream in Polk County, Missouri fed by two springs and the shallow unconfined Springfield Plateau aquifer, a highly karstified aquifer which is made up of limestone and minor interbedded shale-mudstone units. To determine if Leith Creek is gaining or losing, stream flow, water chemistry and temperature sensors were monitored. Stream flow results required multiple visits to take measurements while temperature sensors required two visits, one to install the dataloggers and another to remove the …

Investigating The Thermal Stratification Patterns Of A Shallow Polymictic Boreal Shield Lake And The Effectiveness Of Models In Predicting Shallow Lake Thermal Profiles, Matthew Roberts

Theses and Dissertations (Comprehensive)

Thermal stratification is a core process of lakes which plays a critical role in shaping the ecological dynamics of lakes, influencing major processes like nutrient cycling and oxygen availability. For shallow polymictic lakes, thermal stratification patterns present some unique differences due to the complex and variable nature of these lakes. In this thesis, I examined thermal stratification in a shallow polymictic lake in northwestern Ontario during the ice-free season of 2019 to investigate the frequency, duration, and driving factors of thermal stratification. The lake underwent 146 separate stratification events, with a median duration of 2 hours per event, with a …

Multi-Sensor Data Fusion And Gis-Drastic Integration For Groundwater Vulnerability Assessment With Rainfall Consideration, Wu Jiazhe, Dai Xinrui, Su Yangcheng, Zheng Xiangtian, Bushra Ghaffar, Rabiya Nasir, Ahsan Jamil, Zeeshan Zafar, Mohammad Suhail Meer, M. Abdullah-Al-Wadud, Rahila Naseer, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

In many areas of the world, particularly in arid and semi-arid regions, groundwater is the primary source of fresh water, and it supplies around one-third of the world's fresh water. Agriculture is the primary economic sector on the coast in the southern district (Nowshera). More food productivity is required due to the expanding population and diminishing agricultural lands, which increases the use of chemical pesticides and fertilizers in farming. The current study was conducted in northwestern parts of Pakistan to evaluate the impacts of the frequent use of pesticides and fertilizers in agricultural fields. Nine hydrogeological parameters were considered, and …

Extraordinary 21st Century Drought In The Po River Basin (Italy), Abel Andrés Ramírez Molina, Glenn Tootle, Giuseppe Formetta, Thomas Piechota, Jiaqi Gong

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Recent research identified 2022 as being the year of lowest seasonal April–May–June–July (AMJJ) observed streamflow for the Po River Basin (PRB) in the past two centuries. Expanding upon this research, we applied filters (2-year to 30-year filters) to the AMJJ observed streamflow and identified the late 20th and 21st century as displaying extreme drought. In this study, we introduce PALEO-RECON, an automated reconstruction tool developed to leverage tree ring-based proxies and streamline regression processes. Using PALEO-RECON, we reconstructed the AMJJ streamflow, applying traditional regression techniques and using a nested approach in which 30-, 40-, and 50-year windows within the ~200-year …

Comparing Metabolism And Hypoxia Tolerance Of Native And Non-Native Florida Freshwater Fishes In Climate Change Scenarios, Benjamin A. Share

All HCAS Student Capstones, Theses, and Dissertations

As climate change brings rising water temperatures and lower dissolved oxygen (DO) concentrations to freshwater bodies, it has become increasingly important to understand how this will affect ecosystems with established non-native or invasive species. Fishes of the family Cichlidae are the most pervasive non-native fishes in the Everglades and may increase their range further north under a changing climate. To better understand potential invasibility and competition with native fishes, the metabolism and hypoxia tolerance of non-native Blue Tilapia Oreochromis aureus was compared to native Bluegill Lepomis macrochirus when acclimated across a range of seasonal and projected temperatures. Intermittent-flow respirometry was …

Quantitative Evaluation Of Baseflow Separation Methods Using An Integrated Hydrologic Model: A Case Study In A Snow-Dominated Watershed, Jihad Othman

All Graduate Reports and Creative Projects, Fall 2023 to Present

Baseflow, commonly referred to as the groundwater contribution to streamflow, constitutes approximately 50% of streamflow in mountainous regions of the Western United States. Accurately quantifying the amount of baseflow is critical for water management and decision-making, as it significantly impacts stream water quality, low flow availability, and ecosystem health. Traditionally, baseflow has been estimated using conceptual and automated baseflow separation methods, which are known to be both arbitrary and ambiguous, posing a challenge to validate them. In this study, we developed an integrated hydrologic model that seamlessly integrated the exchange between surface and subsurface flows to physically quantify the baseflow …

Impact Of Irrigation Systems On Water Use And Water Productivity: A Case Study Using Aquacrop In Khartoum, Sudan, Abdalhakam Almagzoop

Department of Agricultural and Biological Systems Engineering: Masters Project Reports

Water scarcity significantly challenges agricultural productivity in arid regions like Khartoum, Sudan. This study evaluates the impact of three irrigation systems—furrow, sprinkler, and surface drip—on the water use and productivity of sorghum (Sorghum bicolor L.) under different climatic conditions using the AquaCrop model. Simulations were conducted for three representative years: a wet year (2022), a normal year (2015), and a dry year (2018). The results demonstrate that irrigation substantially improved water use efficiency and crop yield compared to non-irrigated (rainfed) conditions. Rainfed crops resulted in lower biomass, harvest index, and yield, particularly in the dry year, highlighting the importance …

Enhancing Water Sustainability In North Africa: Literature Review And Synthesis Of Current Knowledge Gaps In Sudan, Osman M. A. Adam

Department of Agricultural and Biological Systems Engineering: Masters Project Reports

This study delves into the critical role of groundwater in addressing global water challenges, with a focus on the Nubian Sandstone Aquifer System (NSAS) in north Africa. Groundwater constitutes a source of potable water, irrigation, and industrial use, especially in arid regions where surface water is limited. We analyzed the status of water quantity, withdrawals, recharge, and geological characteristics in the NSAS, specifically in Sudan, Egypt, and Libya. Though the NSAS is largely an untapped resource, water withdrawals from the NSAS in Egypt, Sudan, and Libya are projected to increase substantially from 2000 to 2100 due to population growth, with …

Informing Management Of American Shad (Alosa Sapidissima) In The Carolinas: Evaluating Novel Fish Passage Approaches And Acoustic Tracking Methods, Margaret Gaither

All Theses

Acoustic telemetry is a valuable tool for fisheries scientists to study the movements and migratory behaviors of aquatic organisms. A critical assumption of this method is that tagged fish exhibit similar behaviors and survival rates as their untagged counterparts. To investigate this, we conducted a 12-week laboratory study on adult American Shad (Alosa sapidissima) using gastroesophageal insertion of acoustic transmitters. We implanted 80 fish with dummy transmitters and monitored tag retention and survival. Our analysis, employing a mixed effects Cox’s proportional hazards model, revealed no significant differences in survival between tagged and control fish, regardless of sex. Additionally, …

Performance Of Acoustic Telemetry And Space Use Of Pallid Sturgeon In The Lower Platte River, Nebraska, Christopher F. Pullano

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

Pallid Sturgeon (Scaphirhynchus albus) are centenarian, potamodromous, rheophiles that historically occupied the Missouri River and Mississippi River basins. Listed on the U.S. Endangered Species Act in 1990, population declines are attributed to habitat fragmentation and degradation, as well as overharvest, and hybridization. A knowledge gap exists regarding the extent to which tributaries facilitate key life stages for Pallid Sturgeon. This study evaluated the capacity of acoustic telemetry to monitor the movements of Pallid Sturgeon in a shallow, braided tributary to the Missouri River. The specific objectives were to (1) evaluate the environmental variables influencing the performance of acoustic …

Investigating Nekton Response To Changing Salinities In The Mississippi Sound: An Experimental And Statistical Approach, Adam Murray

Master's Theses

The Mississippi Sound provides nursery habitats for many coastal species and is recognized for its commercial fisheries. Previous freshening events linked to the Bonnet Carré Spillway, a Mississippi River flood diversion structure, proved catastrophic for oyster populations in the Mississippi Sound, but effects on mobile fish and shellfish species are not well-defined. The planned Mid-Breton Sediment Diversion (MBSD), an initiative to combat wetland loss, is also forecasted to lower salinities in the region, increasing the need to better understand responses of commercially and ecologically important species to freshening events. The objective of this study was to characterize effects of salinity …

Evaporation Basins For Salinity Management, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

An evaporation basin is an engineered earth structure designed to safely store and evaporate saline water discharged from drainage or pumping, while protecting high-value agricultural land, natural assets or built infrastructure.

DPIRD recommends that evaporation basins should form part of an integrated water and salinity management program. Information on this page is a guide only.

It is recommended that landholders seek expert advice plus engineering design and related support from qualified contractors.

Measuring Soil Salinity, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

To make sound decisions on managing saline sites, you need to know the source of salt, how salinisation is occurring, the landscape context, and most importantly, the actual salt concentration of the soil.

The most common 'measures' of salt concentration are actually estimates based on electrical conductivity of a soil and water solution. Soil salt content can be measured in a laboratory by measuring the total dissolved solids in a sample. In the field, salt concentration can also be estimated using electromagnetic induction-based soil sensors.