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Harmful Algal Blooms And Biological Toxins Productions; From Integrated Monitoring Approach To On-Site Solar Photocatalytic Decomposition, Hesam Zaman Khan Malayeri

Civil Engineering Dissertations - Archive

Occurrence of Harmful Algal Blooms (HABs) worldwide has caused concern to environmental and health authorities because of their potential to generate and release biological toxins. In particular, microcystins (MCs) produced from cyanobacteria are of great concern. MCs are among the most powerful natural poisons. The presence of MCs in drinking water sources has raised major concern. The overall goal of this research is to predict formation of biological toxins in water bodies and to develop a new sustainable approach to decompose them, if feasible, on-site and in real-time with minimal efforts, less chemicals, and low energy inputs. In order to …

Post-Liquefaction Residual Strength Assessment Of The Las Palmas, Chile Tailings Failure, Tristan Reyes Gebhart

Master's Theses

Assessment of post-liquefaction residual strength is needed for the development of empirically-based, predictive correlations for earthquake engineering design. Previous practice commonly assigned negligible strengths to liquefied materials for engineering analysis, producing overly-conservative designs. Increasingly available case history data, and improved analytical tools have allowed for more accurate and less overly-conservative estimation of soil residual strength, improving empirical predictive models. This study provides a new case history to the limited suite of (approximately 30) liquefaction failure case histories available for post-liquefaction in-situ strength predictive correlations.

This case history documents the Las Palmas gold mine tailings dam failure, resulting from seismic-induced liquefaction …

Evaluation Of Food Waste Diversion Potential And Economics Of Using Food Waste Dehydrators, Arindam Dhar

Civil Engineering Theses - Archive

According to US EPA (2013), food waste is the second largest component (14.6%) of MSW composition in the US, preceded only by paper. Apart from the negative environmental impacts of food waste through methane and leachate generation, it also incurs huge cost to landfill them. Hence, food waste diversion from landfills is becoming a major issue in landfills across many US states. Though biological treatment of food waste is a potential alternative for food waste diversion, the existing scale of this type of treatment is very narrow. On-site treatment of food waste is a suitable alternative as it can be …

E3.Pt – An E3 Portabledyme Model For Portugal, Anett Großmann, Frank Hohmann

International Congress on Environmental Modelling and Software

E3 models are environmentally extended economic models. They are extensively used for impact assessment of energy, climate and resource policies at national and international level. E3 models have proven to be suitable tools for quantifying effects on the economy, environment and energy system. Usually, the structure and documentation of such models are only accessible by the model builders. They are facing the allegation to be a "black box" meaning that only their creators are able to operate and fully understand the model system. Decision makers are often only engaged at the end of the model building process to discuss the …

A Framework For Decision-Making In Cases Of Invasive Species, Peter A. Khaiter, Marina G. Erechtchoukova, Sina Roushan

International Congress on Environmental Modelling and Software

Invasion of nonindigenous species is one of the most pressing global challenges, causing substantial environmental, economic and social harm. Invasion of alien species alters the composition, structure and functioning of invaded ecosystems as well as the services they generated before the invasion. Decisions about the management of invasive cases are inherently difficult because of the multifactorial and multiattribute scope of the problem. In particular, the resilience limits of invaded ecosystems to fully recover original, pre-invaded states remain unclear. To facilitate management efforts, decision-makers and environmental practitioners require a framework integrating relevant knowledge and acting as a supporting expert system. The …

Simulating Spatial Changes In Vegetation-Livestock Interactions Under Different Landscape Structures: A Multi-Agent System Applied To Agro-Pastoral Territories, Mamadou Sané, Jonathan Vayssières, Myriam Grillot, Alassane Bah, Alexandre Ickowicz

International Congress on Environmental Modelling and Software

Free-range and common-grazing ruminants play a major role in the functioning and the provision of ecosystem services by agro- and silvo-pastoral ecosystems in sub-Saharan Africa. To assess how landscape structure affects the nature of environment-herd-services interactions, this paper describes a Multi-Agent System (MAS) that simulates daily herd movements in a dynamic environment. The model is used to study how the overall productivity of an agricultural territory is affected by the spatial organization of its different landscape units. The originality of this model lies in fine representation, in hourly time steps, of a herd’s movements and activities over the seasons depending …

Evapotranspiration Mapping Using Sebal Algorithms To Account For Agricultural Water Uses In The Upper Pangani, Tanzania, Anna Msigwa, Ann Van Griensven, Hans C. Komakech, Boud Verbeiren, Tim Hessels, Wim G. M. Bastiaanssen

International Congress on Environmental Modelling and Software

To make informed decisions, river basin managers requires information on demands and actual usage from different sectors in the basin. Such water use information has to be adequate in terms of quantities used per sector, where and when. However, because of high costs of maintaining equipment for monitoring use, it is very difficult to obtain this information in developing arid and semi- arid areas of Sub-Saharan Africa. The use of proxy method such as calculation of evapotranspiration is proposed as a cheaper means for such data acquisition. Water consumption through crop evapotranspiration (ET) is a major component of water withdrawal, …

Up In The Air: Understanding Vulnerability When Toilets Fly, Amy Krakowka Richmond, Suzanne Pierce, Sethi Gautam

International Congress on Environmental Modelling and Software

Across sub-Saharan Africa, both natural and social factors contribute to household level vulnerability. This case study focuses specifically on Uganda, which has made progress towards meeting the United Nation’s Millennium Development Goals, most notably halving the proportion of the population that is below the poverty line. Despite these impressive achievements, many households remain vulnerable to multiple social and environmental stressors. A better understanding of the drivers of household level vulnerability will assist stakeholders and policy-makers in determining what drives vulnerability at a household level, where vulnerable populations are, and suggest what type of aid to target specific locations to be …

Hindcasting The Dynamics Of An Eastern Mediterranean Marine Ecosystem Under The Impacts Of Multiple And Cumulative Stressors, X. Corrales, M. Coll, E. Ofir, M. Goren, D. Edelist, J. J. Heymans, G. Gal

International Congress on Environmental Modelling and Software

An important challenge for conserving and managing marine ecosystems is to advance our understanding of how multiple human stressors, environmental factors and marine resources interact and influence each other. The ecosystems of the Israeli Mediterranean coast have undergone significant ecological changes in recent decades caused primarily by the introduction of invasive species through the Suez Canal, intense fishing activities and the effects of climate change. An Ecopath model representing the continental shelf of the Israeli Mediterranean coast was calibrated and fitted to the available time series from early 1990’s to 2010 using the Ecosim temporal dynamic modeling approach. The model …

Application Of The Swat Model To Investigate Surface Runoff And Nitrate Flux Towards The Mediterranean Sea: Case Of The Tafna Catchment (North-West Of Africa), Amin Zettam, Amina Taleb, Sabine Sauvage, José Miguel Sanchez-Perez, Laurie Boithias, Nouria Belaidi

International Congress on Environmental Modelling and Software

Water in North-West of Africa is an increasingly valuable resource due to high competition between agriculture, industry and drinking water supply, accentuated by frequent drought conditions in a semi-arid climate. For a few decades, the demographic explosion, the development of agriculture and industry, and the building of water infrastructures (dams) have modified the water fluxes and the biogeochemical cycle of nitrogen towards an increased production of nitrates in waters. The objectives of this study are to propose a modelling approach to quantify the contribution of the Tafna coastal watershed (North-West of Africa) to the flux of nitrates into the Mediterranean …

From Research Data To Web-Based Policy Tools: User-Centered Design Techniques In The Development Of The Agmip Impacts Explorer, Joske Houtkamp, Inge La Rivière, Hugo De Groot, Sander Janssen, Arjan De Jong

International Congress on Environmental Modelling and Software

decision making through a web-based tool is a complex challenge. Research projects are generally not designed to meet the information needs of specific stakeholder groups. Furthermore, tools developed in these projects are usually intended to disseminate research data on a wide scale, not to provide answers to specific questions of these stakeholders. User-centered design techniques can guide the development process of such tools, to enhance their usefulness and thus the applicability of the research outcomes for the intended audience. We applied techniques for user requirements analysis of the Impacts Explorer tool in the AgMIP research project, which models the impacts …

The Validation Of Algal Growth Processes In A Water Quality Model Using Remote Sensing Data, A. R. Slaughter, S. K. Mantel

International Congress on Environmental Modelling and Software

The Water Quality Systems Assessment Model (WQSAM) uses the concept of requisite simplicity within the context of modelling water quality of data scarce South African surface waters. Although WQSAM has successfully simulated the frequency distribution of observed historical nutrient data for various catchments in South Africa, the validation of algal and macrophyte growth processes in the model is a challenge because of a lack of observed data. Remote sensing data can provide an estimate of algal growth within reservoirs. Therefore, this study aimed to validate the WQSAM simulations of algal growth using remote sensing estimations of primary production in reservoirs. …

Modelling Social Ecological Dynamics With Transfers Of Vulnerability And Robustness. Examples With Adaptation To Coastal Vulnerability, Olivier Barreteau, J. Marty Anderies, Bruno Bonté, Pauline Brémond, Frédéric Grelot, Chloé Guerbois, Tara Quinn

International Congress on Environmental Modelling and Software

Adaption patterns undertaken by policy makers within their own jurisdiction may bump in adaptation patterns undertaken by others at their own level. The consequences of these interactions may lead to mutual reinforcement or to cancelling each policy maker’s adaptation capacity. In this presentation, we consider following Anderies (2014) that autonomous SES have their own adaptive management as an autonomous feedback loop. We take on seriously the concept of pluralism of agency in SES: any goal can be used as the root for a specific feedback loop. We identify the interactions between these loops to characterize transfers of vulnerability or robustness …

On The Use Of Finite-Difference Model To Evaluate The Impact Of Underground Water Overexploitation, Hani A., Bougherira N., Djabri L., Chaffai H., Lallahem S.

International Congress on Environmental Modelling and Software

The potentiometric surface in the Annaba basin, which covers an area of 264 km², has declined significantly since 1995. A transient multilayer model has been developed to synthesise the hydrologic data. The groundwater flow was modelled using the finite difference method with a horizontal dimension of 500 x 500 m for the cells. The model consists of two layers, the first corresponding to the alluvial phreatic aquifer and the second to the deep confined aquifer, and is calibrated against the steady state groundwater heads recorded before 1996. Under steady-state conditions, the correspondence between simulated and observed water levels …

Government Motivation-Embedded Return Guarantee For Urban Infrastructure Projects Based On Real Options, Qingpeng Man, Chengshuang Sun, Yuesheng Fei, Martin Skitmore, Yong Bai, Weizhuo Lu

Civil and Environmental Engineering Faculty Research and Publications

Governments usually guarantee the amount of investment income to private sector partners to encourage their participation in Public-Private Partnership urban infrastructure development projects, with the ‘float return on investment guarantee’ being the main method in use by the Chinese government today. The current problems with the float return on investment guarantee are analysed and a guarantee approach with embedded motivational behaviour is presented as an alternative. A pricing method option is then introduced as the motivation-embedded return guarantee has similar characteristics to real options. From this, a valuation model is developed that provides the basis of a new systematic method …

Groundwater Recharge And Associated Uncertainty Estimation Combining Multi-Method And Multi-Scale Approaches, S. Lanini, Y. Caballero

International Congress on Environmental Modelling and Software

Groundwater resource assessment is a major concern for water managers who have to balance water demands and resources at a basin or territory scale. One operational way to address this question is to estimate the part of recharge which is linked to precipitation. Many methods to estimate groundwater recharge are described in the literature, varying in terms of time scale and the nature of the data they treat. They do not always provide a suitable estimate of uncertainty. To obtain both a realistic estimation of groundwater recharge and a confidence interval at the hydrogeological basin scale, we propose a multi-method …

An Integrated Modelling Approach To Climate Change And Malaria Vulnerability Assessments, Esther Achieng Onyango, Oz Sahin, Cordia Chu, Brendan Mackey

International Congress on Environmental Modelling and Software

Malaria is one of the key research concerns in climate change-health relationships. Numerous risk assessments and modelling studies providing evidence that the transmission range of malaria will expand with rising temperatures resulting in adverse impacts on vulnerable communities. This risk is significant in East Africa whereby current research shows an expansion of malaria into the highland areas due to changes in temperature and rainfall. While there exist multiple lines of evidence for the influence of climate change on malaria and the risk posed to vulnerable communities, there is insufficient understanding of the complexity of factors influencing the spread of the …

Using Sddp To Perform Basin-Wide Water Resources Assessments With Limited Data Availability, Charles Rougé, Amaury Tilmant

International Congress on Environmental Modelling and Software

In many situations, water resources assessments are hindered by the limited availability of data concerning both water supplies and demands. Stochastic dual dynamic programming (SDDP) is one of few solutions available to determine optimal allocation policies in large-scale water resources systems. Yet, limited data on water demands and hydraulic infrastructure leads to the existence of multiple near-optimal solutions (MNOS). This work shows that when MNOS exists, SDDP is very sensitive to even minimal variations of the problem setting, e.g. initial conditions – we call this “algorithmic chaos”. Besides, the approximations of the benefit-to-go function that SDDP constructs at each stage …

Methane Extraction From Lake Kivu: A Case Study For Model-Based Policy, Martin Schmid, Alfred Wüest

International Congress on Environmental Modelling and Software

Lake Kivu in East Africa contains enormous amounts of dissolved carbon dioxide and methane. The dissolved methane is increasingly used as a resource to produce electricity, with two power plants currently in operation and several additional facilities in planning. The design of such gas extraction facilities needs to take into account possible negative impacts: if badly designed, the extraction could disturb the lake’s permanent density stratification and thus risk to create a catastrophic gas eruption; and it could increase nutrient fluxes from the deep water to the surface layers, leading to eutrophication and related negative consequences for the ecosystem, fisheries …

Cfd Study Of Decay Function Of Wall Shear Stress With Scour Around Complex-Shape Bridge Pier, Chen Li

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

Pier scour problem is close related to the safety of bridges. The Federal Highway Administration of the United State also has a great interest in studying the relation between hydraulic loadings and scour depth. The current technological problem of directly measuring hydraulic loadings on a dynamic bed using physical experiments and the weak capacity to simulate the real scour processes with CFD methods inspired the development of a hybrid approach by combining them to study pier scour.

This research specifically focuses on the CFD part of the hybrid method. A series of three-dimensional (3-D) CFD models were developed with unsteady …

A Tool For Downscaling Weather Data From Large-Grid Reanalysis Products To Finer Spatial Scales For Distributed Hydrological Applications, Avirup Sen Gupta, David G. Tarboton

Civil and Environmental Engineering Faculty Publications

A downscaling tool was developed to provide sub-daily high spatial resolution surfaces of weather variables for distributed hydrologic modeling from NASA Modern Era Retrospective-Analysis for Research and Applications reanalysis products. The tool uses spatial interpolation and physically based relationships between the weather variables and elevation to provide inputs at the scale of a gridded hydrologic model, typically smaller (∼100 m) than the scale of weather reanalysis data (∼20–200 km). Nash-Sutcliffe efficiency (NSE) measures greater than 0.70 were obtained for direct tests of downscaled daily temperature and monthly precipitation at 173 SNOTEL sites. In an integrated test driving the Utah Energy …

Potential For Alkali–Silica Reaction In Radiation Shielding Concrete Containing Special Aggregates, Daria Jóźwiak-Niedźwiedzka, Michał A. Glinicki, Karolina Gibas

International Conference on Durability of Concrete Structures

In the present study, the potential for the alkali–silica reaction (ASR) in radiation shielding concrete containing special aggregates is presented. The tests were performed on two kinds of aggregate: (1) high-density aggregate to absorb the gamma radiation (barite, magnetite, and hematite) and (2) mineral with high bound water content to attenuate the neutron flux (serpentinite). The optical microscopy in transparent light on thin sections, XRD and XRF method, was used to assess the mineral composition of aggregates. ASTM C1260 test method for potential alkali reactivity of aggregates was applied also to investigate the effect of different content and crystal size …

Structural Calculations For Nepal Vocational Learning Center, Nicholas Petrarca

Architectural Engineering

This project goal is to build a Leadership Vocational School for youth, women, differently abled, and local leaders of rural and Kathmandu Nepal. The client for this project is an organization called Sakcham Rural Nepal and they partnered with a humanitarian organization called Journeyman International to find Architecture and Architectural Engineering students to design a safe, attractive and functional building to fit their needs.

Nanofiltration Rejection Of Contaminants Of Emerging Concern From Municipal Water Resource Recovery Facility Secondary Effluents For Potable Reuse Applications, Steven Michael Jones

Graduate Theses and Dissertations

As reuse of municipal water resource recovery facility (WRRF) effluent becomes vital to augment diminishing fresh drinking water resources, concern exists that conventional barriers may prove deficient and the upcycling of contaminants of emerging concern (CECs) could prove harmful to human health and aquatic species if more effective and robust treatment barriers are not in place.

There are no federal Safe Drinking Water Act (SDWA) regulations in place specifically for direct potable reuse (DPR) of WRRF effluent. Out of necessity, some states are developing their own DPR reuse regulations. Currently, reverse osmosis (RO) is the default full advanced treatment (FAT) …

Framework Of Performance-Based Contracting For Chip Seal And Striping Maintenance Activities, Kishor Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the United States, there are more than four million miles of road network and new roads are being constructed every year. Most of the road networks were constructed more than two decades ago. Therefore, the age of the majority of the pavement inventory has exceeded original design life. This results in increased work load for the maintenance division of the state Departments of Transportation (DOTs). To maintain the road system, state DOTs use In-House or outsource maintenance works to private contractors using Method Based Contracting (MBC), or Performance Based Contracting (PBC), or any combination of these three. Literature reviews …

Evapotranspiration Estimation: A Study Of Methods In The Western United States, Clayton S. Lewis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Theoretical water use of well-watered vegetation in the western United States was investigated by comparing a gridded dataset developed from satellite and ground instruments to weather stations representative of irrigated agricultural conditions. Since wetter environments are cooler and therefore subject to lower levels of evaporation than the same scenario with warmer temperatures, models derived from dryland and often populated areas overestimate potential plant needs in semi-arid or arid conditions. Evaluation of the model revealed an acceptable fit for air temperatures and solar radiation but with less confidence in humidity and wind speeds. Ultimately, the last two parameters were minor components …

Causes Of Change Orders And Its Impact On Road Maintenance Contracts, Kabindra Kumar Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Change orders (CO) commonly generate cost-growth, schedule-growth or both, in construction as well as in maintenance contracts. Literature reviews revealed that the causes and impact of CO on new construction contracts had been comprehensively studied, but the causes and impact of CO in maintenance contracts remained neglected. This study collected CO data on road maintenance contracts to determine the amount of CO and the most frequent and high-risk road maintenance activities that had CO. A Delphi study was conducted with 33 maintenance engineers from the state Department of Transportation (DOT) to identify causes of CO and its impact on cost …

Characterization Of A Continuous-Flow Reactor For Solar Uv Water Disinfection, Margaret M. Busse

Open Access Theses

Lack of access to safe water is a common problem in many developing countries (UNICEF/WHO, 2011). Fortunately, solar ultraviolet (UV) radiation is abundantly available in many of these same areas, and it has been used to accomplish disinfection of drinking water by processes that involve no electrical power, such as solar water disinfection (SODIS). However, conventional SODIS systems are limited by batch processing and exclusion of UVB radiation, which is the most germicidally-active portion of the UV spectrum (Coohill and Sagripanti, 2008). To address these limitations, a continuous-flow solar UV disinfection system was developed to amplify ambient solar UV radiation, …

A Review Of Advances In The Identification And Characterization Of Groundwater Dependent Ecosystems Using Geospatial Technologies, Isabel C. Pérez Hoyos, Nir Y. Krakauer, Reza Khanbilvardi, Roy A. Armstrong

Publications and Research

Groundwater Dependent Ecosystem (GDE) protection is increasingly being recognized as essential for the sustainable management and allocation of water resources. GDE services are crucial for human well-being and for a variety of flora and fauna. However, the conservation of GDEs is only possible if knowledge about their location and extent is available. Several studies have focused on the identification of GDEs at specific locations using ground-based measurements. However, recent progress in remote sensing technologies and their integration with Geographic Information Systems (GIS) has provided alternative ways to map GDEs at a much larger spatial extent. This paper presents a review …

Alkali Silica Reaction (Asr) Mitigation For Arkansas Region, Lois Farouk Kamel

Theses and Dissertations

The objective of this research is to mitigate and prevent the alkali silica reactivity (ASR) in highway construction projects. ASR is a deleterious reaction initiated when the silica content of the aggregate reacts with alkali hydroxides in the mix in the presence of relatively high moisture content. The ASR results in the formation of an expansive white colored gel-like material which forms the destructive tensile stresses inside hardened concrete. Different types of local aggregates available in the State of Arkansas were mixed, mortar bars and concrete specimens were poured according to the ASTM specifications. Specimens' expansion was measured versus time, …