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

Environmental Engineering Commons™

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

6,147 Full-Text Articles 11,300 Authors 3,297,484 Downloads 148 Institutions

All Articles in Environmental Engineering

Faceted Search

6,147 full-text articles. Page 191 of 246.

An Analysis Of Secular Change In Tides At Open-Ocean Sites In The Pacific, Edward D. Zaron, David A. Jay 2014 Portland State University

An Analysis Of Secular Change In Tides At Open-Ocean Sites In The Pacific, Edward D. Zaron, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Hourly sea level is examined at 25 open-ocean stations in the Pacific Ocean with records longer than 30 yr. A search for trends finds that the amplitude of the dominant semidiurnal tide M2 is increasing at 12 of the 13 sites where a statistically significant trend can be identified. It is also found that nontidal variance in the neighborhood of M2 is decreasing at all 12 of the sites where a significant increase in M2 tide is occurring. The trend in amplitude of the dominant diurnal tide K1 is significant at six stations, and it is …


Feasibility Of Mainstream Nitrite Oxidizing Bacteria Out-Selection And Anammox Polishing For Enhanced Nitrogen Removal, Pusker Raj Regmi 2014 Old Dominion University

Feasibility Of Mainstream Nitrite Oxidizing Bacteria Out-Selection And Anammox Polishing For Enhanced Nitrogen Removal, Pusker Raj Regmi

Civil & Environmental Engineering Theses & Dissertations

Short-cut nitrogen removal avoids nitrite oxidation to nitrate by nitrite oxidizing bacteria (NOB) and allows a) reduction of formed nitrite to nitrogen gas via heterotrophic denitrification and/or b) oxidation of remaining ammonia with formed nitrite to nitrogen gas via anaerobic ammonia oxidation (anammox). The precondition for achieving shortcut nitrogen removal is suppression of NOB, which is favored by warm and high ammonia strength conditions found in internally generated ammonia-rich waste streams through anaerobic digestion of waste solids referred to as sidestreams or reject water. The discovery of anammox bacteria in the mid-1990s, which are capable of transforming NH4+ …


Evaluation Of The Epa Swmm Model To Simulate Low Impact Development Features In An Urban Stormwater Environment, Holly Ann Carpenter 2014 Old Dominion University

Evaluation Of The Epa Swmm Model To Simulate Low Impact Development Features In An Urban Stormwater Environment, Holly Ann Carpenter

Civil & Environmental Engineering Theses & Dissertations

This research thesis explores the use of the Environmental Protection Agency's (EPA) Stormwater Water Management Model (SWMM) to model an urban watershed with a developed stormwater management system and test the SWMM model's ability to simulate Low Impact Development (LID) features by proposing typical LID features that can be retrofitted to the developed study area. The SWMM model is established with an existing survey of the study area's stormwater management system, and due to the lack of field data for the study area, the model developed in this research thesis is calibrated with the consideration of a published stormwater model …


Study Of Process Control Strategies For Biological Nutrient Removal In An Oxidation Ditch, Leslie Ann Knapp 2014 University of South Florida

Study Of Process Control Strategies For Biological Nutrient Removal In An Oxidation Ditch, Leslie Ann Knapp

USF Tampa Graduate Theses and Dissertations

Advanced wastewater treatment plants must meet permit requirements for organics, solids, nutrients and indicator bacteria, while striving to do so in a cost effective manner. This requires meeting day-to-day fluctuations in climate, influent flows and pollutant loads as well as equipment availability with appropriate and effective process control measures. A study was carried out to assess performance and process control strategies at the Falkenburg Road Advanced Wastewater Treatment Plant in Hillsborough County, Florida.

Three main areas for control of the wastewater treatment process are aeration, return and waste sludge flows, and addition of chemicals. The Falkenburg AWWTP uses oxidation ditches …


Low-Cost Household Groundwater Supply Systems For Developing Communities, Michael Maccarthy 2014 University of South Florida

Low-Cost Household Groundwater Supply Systems For Developing Communities, Michael Maccarthy

USF Tampa Graduate Theses and Dissertations

ABSTRACT

Self-supply is widely reported across various contexts, filling gaps left by other forms of water supply provision. This research assesses low-cost household groundwater supply technologies in markets in developing country contexts of sub-Saharan Africa and Latin America, with a focus on the potential for improving Self-supply technology implementation and markets in sub-Saharan Africa. Specifically, a mature and unsubsidized Self-supply market for Pitcher Pump systems (suction pumps fitted onto hand-driven boreholes) is studied in an urban context in Madagascar, EMAS low-cost water supply technologies are assessed in Bolivia, and a technical comparison is completed with manual EMAS Pumps and family …


Integration Of Models For Low Carbon Economy, Getachew F. Belete, Alexey Voinov 2014 University of Twente

Integration Of Models For Low Carbon Economy, Getachew F. Belete, Alexey Voinov

International Congress on Environmental Modelling and Software

Designing the transition to low carbon economy is a very complex task that touches upon a wide variety of climate-energy-economic systems. We need to explore the various possible climate mitigation scenarios at different temporal and spatial scales. However, due to the diversity of the involved disciplines it is difficult to find one complete and unified modeling approach that works equally well in all those different domains. As a result we have to select 'appropriate' models, which represent only specific aspects of the scenarios and assemble them 'coherently'. In this research we have identified some challenges in integrating multidisciplinary models; and …


A Decision Support System Approach For Identifying Poliutant Source For Optimization Of Beneficial Management Practices Scenario Modelling In Lake Winnipeg Watersheds, Isaac Wong, Luis Leon, Jason Vanrobaeys, Craig McCrimmon, Phil Fong 2014 Environment Canada

A Decision Support System Approach For Identifying Poliutant Source For Optimization Of Beneficial Management Practices Scenario Modelling In Lake Winnipeg Watersheds, Isaac Wong, Luis Leon, Jason Vanrobaeys, Craig Mccrimmon, Phil Fong

International Congress on Environmental Modelling and Software

The Soil and Water Assessment Tool (SWAT) results can be used to source trace loading "hotspots• for optimally locating beneficial management practices (BMP). It is possible to trace upstream and compute the relative contribution of each sub-basin to a point of interest, accounting for in-stream processes, reservoirs and point sources. A decision support system (DSS) framework was developed to run SWAT, perform the otherwise tedious process of source tracing "hotspots" and to optimize BMP locations. The "Crop to Hay- land use change BMP scenario was applied in an attempt to reduce annual loadings of total phosphorus (TP) for three Lake …


Agroecosystem-Watershed (Ages-W) Model Delineation And Scaling, Timothy R. Green, Robert H. Erskine, James C. Ascough II, Bruce Vandenberg, Björn Pfennig, Holm Kipka, Olaf David, Micheal L. Coleman 2014 U.S. Department of Agriculture - Agricultural Research Service

Agroecosystem-Watershed (Ages-W) Model Delineation And Scaling, Timothy R. Green, Robert H. Erskine, James C. Ascough Ii, Bruce Vandenberg, Björn Pfennig, Holm Kipka, Olaf David, Micheal L. Coleman

International Congress on Environmental Modelling and Software

Water movement and storage within an agricultural watershed can be simulated at different spatial resolutions of land areas or hydrological response units (HRUs). Interactions between HRUs in space and time vary with the HRU sizes, such that natural scaling relationships are confounded with the simulation scales. Scaling concepts can be tested using the AgroEcoSystem­ Watershed (AgES-W) model with different resolutions of HRUs. Here, we delineated a 56-ha agricultural watershed in northern Colorado, USA farmed primarily under a wheat-fallow rotation. Factors used to distinguish HRUs included topography (surface flow paths), land use (crop strips and native grass), and mapped soil units …


Global Sensitivity Analysis Of Key Parameters In A Process-Based Sugarcane Growth Model - A Bayesian Approach, Justin Sexton, Yvette Everingham 2014 James Cook University

Global Sensitivity Analysis Of Key Parameters In A Process-Based Sugarcane Growth Model - A Bayesian Approach, Justin Sexton, Yvette Everingham

International Congress on Environmental Modelling and Software

While several statistical methods are available to analyse model sensitivity, their application to complex process-based models is often impractical due to the large number of simulation runs required. A Bayesian approach to global sensitivity analysis can greatly reduce the number of simulation runs required by building an emulator of the model which is less computationally demanding. A Gaussian Emulation Machine (GEM) was used to efficiently assess the sensitivity of key agronomic outputs from the APSIM-Sugar crop model to influential input parameters. The sensitivity of simulated biomass and sucrose at harvest was assessed on 14 parameters representing varietal differences and growth …


Dynamic Feedback Between Land Use And Hydrology For Ecosystem Services Assessment, Seleshi Getahun Yalew, Tobias Pilz, Christian Schweitzer, Stefan Liersch, Johannes van der Kwast, Marloes L. Mul, Ann van Griensven, Pieter van der Zaag 2014 UNESCO-IHE Institute of Water Education

Dynamic Feedback Between Land Use And Hydrology For Ecosystem Services Assessment, Seleshi Getahun Yalew, Tobias Pilz, Christian Schweitzer, Stefan Liersch, Johannes Van Der Kwast, Marloes L. Mul, Ann Van Griensven, Pieter Van Der Zaag

International Congress on Environmental Modelling and Software

Ecosystem services assessment requires an integrated approach, as it is influenced by elements such as climate, hydrology and socio-economics, which in turn influence each other. However, there are few studies that integrate these elements in order to assess ecosystem services. Absence of integrated approach to modelling hydrological and land-use changes, for instance, often oversights the dynamic feedback between the two processes. Dynamic changes in land-use should be fed into hydrological models and vice-versa at each time-step for a more realistic representation. In this study, this approach is demonstrated with a case study of the uThukela catchment, South Africa. There is …


Ontology Mapping In Semantic Time Series Processing In Climate Change Prediction, Bojan Božić, Jan Peters-Anders, Gerald Schimak 2014 Austrian Institute of Technology

Ontology Mapping In Semantic Time Series Processing In Climate Change Prediction, Bojan Božić, Jan Peters-Anders, Gerald Schimak

International Congress on Environmental Modelling and Software

In today's time series processing there is more and more a need for addressing diverse user groups interested in a specific domain with appropriate user tailored time series data. The complexity of time series (e.g. involved data from different data sources and/or domains, visualization and representation, etc.) is growing rapidly. As a consequence, it means that users need to find a path through the jungle of time series data. After we have presented our concepts for semantic time series filtering and enrichment of time series with meta-information and annotations (Božić et al., 2012), we are now going to present a …


Metadata Extraction Using Semantic And Natural Language Processing Techniques, Rob Knapen, Thomas Hüsing, Klaus Jacob, Yke van Randen, Stefan Reis, Onno Roosenschoon, Sander Janssen 2014 Wageningen University and Research Centre

Metadata Extraction Using Semantic And Natural Language Processing Techniques, Rob Knapen, Thomas Hüsing, Klaus Jacob, Yke Van Randen, Stefan Reis, Onno Roosenschoon, Sander Janssen

International Congress on Environmental Modelling and Software

The World Wide Web and related technologies are playing an increasing role in the field of Integrated Environmental Modelling (IEM). Model integration software frameworks are more and more becoming web-enabled. The technologies and standards of the Web are used to access and run simulation models remotely (known as the Web of models) and are considered for enabling interoperability across model integration frameworks. Furthermore there is a growing number of local and global initiatives to provide open access to environmental data (Web of data) that can potentially be used as input for the scientific models. The availability of descriptive information of …


Improved Implicit Stochastic Optimization Technique For Multireservoir Water Systems Under Drought Conditions, Andrea Sulis 2014 University of Cagliari

Improved Implicit Stochastic Optimization Technique For Multireservoir Water Systems Under Drought Conditions, Andrea Sulis

International Congress on Environmental Modelling and Software

Drought is a creeping phenomenon, making its onset and end difficult to determine. Damages from droughts can exceed those resulting from any other natural hazard, although it is difficult to assign a monetary value to them. In the Mediterranean area a severe drought period occurred over the years 2000-2002 and economic losses from that drought exceeded 250 million euros in Sardinia (Italy) (source: ENAS Regional Water Authority). Currently, technological developments and environmental modelling tools are improving our ability to more effectively manage water supply systems. Models can provide decision makers with better and more timely data and information. In this …


Challenges/Advances In Distributed Watershed Modeling: A Review And Application Of The Agroecosystem-Watershed (Ages-W) Model, James C. Ascough II, Timothy R. Green, Olaf David, Holm Kipka, Gregory S. Mcmaster, Manfred Fink, Peter Krause, Sven Kralisch 2014 USDA-ARS-NPA, Agricultural Systems Research Unit

Challenges/Advances In Distributed Watershed Modeling: A Review And Application Of The Agroecosystem-Watershed (Ages-W) Model, James C. Ascough Ii, Timothy R. Green, Olaf David, Holm Kipka, Gregory S. Mcmaster, Manfred Fink, Peter Krause, Sven Kralisch

International Congress on Environmental Modelling and Software

Progress in the understanding of physical, chemical, and biological processes influencing water quality, coupled with advances in the collection and analysis of hydrologic data, provide opportunities for significant innovations in the manner and level with which watershed-scale processes may be quantified and modeled. This paper first provides a brief review of current challenges and advances in distributed watershed modeling including quantifying and coping with the uncertainty, data availability, influence of data resolution and scaling issues, and the use of environmental modeling frameworks that help maintain model modularity, reusability, and interoperability (or compatibility). Important findings and observed trends from this work …


Linking A Modified Epic-Based Plant Growth Model (Upgm) With A Component-Based Watershed Model (Ages-W), Gregory S. Mcmaster, James C. Ascough II, Debora A. Edmunds, Olaf David, Larry E. Wagner, Fred A. Fox, Robert H. Erskine, Holm Kipka, Timothy R. Green 2014 USDA-ARS-NPA, Agricultural Systems Research Unit

Linking A Modified Epic-Based Plant Growth Model (Upgm) With A Component-Based Watershed Model (Ages-W), Gregory S. Mcmaster, James C. Ascough Ii, Debora A. Edmunds, Olaf David, Larry E. Wagner, Fred A. Fox, Robert H. Erskine, Holm Kipka, Timothy R. Green

International Congress on Environmental Modelling and Software

Agricultural models and decision support systems (DSS) for assessing water use and management are increasingly being applied to diverse geographic regions at different scales. This requires models that can simulate different crops, however, very few plant growth models are available that "easily" can simulate the growth of many common and alternative crops. One option available is a suite of plant growth models based on the original plant growth model used in EPIC (Erosion Productivity Index Calculator). Various versions of the original EPIC plant growth model have been used in other agroecosystem models such as the Wind Erosion Prediction System (WEPS), …


Assessing The Transition To A Low-Carbon Economy Using Actor-Based System-Dynamic Models, Dmitry V. Kovalevsky, Klaus Hasselmann 2014 Nansen International Environmental and Remote Sensing Centre, Saint Petersburg State University, Nansen Environmental and Remote Sensing Center

Assessing The Transition To A Low-Carbon Economy Using Actor-Based System-Dynamic Models, Dmitry V. Kovalevsky, Klaus Hasselmann

International Congress on Environmental Modelling and Software

For a comprehensive analysis of climate mitigation policies, Integrated Assessment models (IAMs) of the coupled climate-socioeconomic system are needed. However, while there is general agreement on the physics of the climate system, the dynamics of the socioeconomic system is still the subject of considerable controversy. This has become particularly apparent since the recent global financial crisis. To explore the dynamics of the socio-economic system, a family of socio-economic models is proposed that incorporates the various alternative assumptions regarding the behaviour of the different economic actors that govern the evolution of the socio-economic system. The model family needs to be developed …


Enhancing The Policy Relevance Of Scenarios Through A Dynamic Analytical Approach, Céline Guivarch, Vanessa Schweizer, Julia Rozenberg 2014 Ecole des Ponts ParisTech, Cired

Enhancing The Policy Relevance Of Scenarios Through A Dynamic Analytical Approach, Céline Guivarch, Vanessa Schweizer, Julia Rozenberg

International Congress on Environmental Modelling and Software

We present a new dynamic analytical approach for studying scenarios produced by an integrated assessment {IA) model. Our approach involves the analysis of a large number of scenarios, which can better address three principal shortcomings of how uncertainty is traditionally handled in IA scenario studies. The shortcomings are all a result of the prevailing practice of investigating a small number of scenarios and include (1) the ad hoc nature of exploring vast socioeconomic uncertainties with only a small number of scenarios; (2) the conventional representation of alternative scenario typologies as "parallel universes• or "diverging universes•, which provide little insight on …


Development Of A Decision Support Tool To Allocate Irrigation Water On Competitive Basis: Application To Kathiraveli Village, Sri Lanka, Tom Le Cerf, Muhammed A. Bhuiyan 2014 Engineers Without Borders

Development Of A Decision Support Tool To Allocate Irrigation Water On Competitive Basis: Application To Kathiraveli Village, Sri Lanka, Tom Le Cerf, Muhammed A. Bhuiyan

International Congress on Environmental Modelling and Software

This paper focuses specifically on the irrigation field and water supply tanks for ways to improve efficiency of water use and increase the resilience to climatic variability. The purpose of this paper is to develop an excel-based water balance model that will allow the maximum cropping area be planted in the upcoming agricultural season. The model consists of three modules: a crop water requirement calculator that allows the water requirements of specific crops to be compared, a water tank balance model, and a model which simulates the storage in the permanent wetland attached to the irrigation tank. The hydrological computation …


Modelling Biofilm Based Technologies With Activated Sludge Unit Processes: A Short Cut To Performance Simulation?, Noella Jones, Maebh Grace, Eoghan Clifford 2014 NUI Galway

Modelling Biofilm Based Technologies With Activated Sludge Unit Processes: A Short Cut To Performance Simulation?, Noella Jones, Maebh Grace, Eoghan Clifford

International Congress on Environmental Modelling and Software

Biofilm-based passive aeration systems (PAS) have attracted recent attention as alternative, energy efficient and low maintenance technologies in the wastewater sector. However the modelling of biofilm-based PAS offers unique challenges for modellers, particularly where new technologies are not easily simulated using existing commercial modelling software. However, if the modeller is concerned only with simulating "macro" plant performance (e.g. key effluent concentrations and cycle analysis) it may be possible to efficiently model these technologies using "surrogate" unit process systems (e.g. using an activated sludge process to model a biofilm process). The pumped flow biofilm reactor (PFBR); a batch biofilm technology, is …


A Best-Worst Scaling Model Of Climate Change Abatement By Australian Farmers, Marit E. Kragt, Nikki Dumbrell, Fiona Gibson 2014 University of Western Australia, Commonwealth Scientific and Indudstrial Research Organisation (CSIRO)

A Best-Worst Scaling Model Of Climate Change Abatement By Australian Farmers, Marit E. Kragt, Nikki Dumbrell, Fiona Gibson

International Congress on Environmental Modelling and Software

Storing carbon from the atmosphere in terrestrial sinks has been proposed as an important way to mitigate climate change and is a major focus in Australia's climate change policies. Mitigation by changing agricultural practices is seen as a promising way to achieve significant reductions in C02 concentrations. Several policies therefore aim to stimulate farmers to adopt so-called 'carbon farming' practices. However, there is little information about farmers' ability and willingness to adopt carbon farming. We present a best-worst scaling model to analyse farmers' decisions about adopting climate change mitigating practices. Best-worst scaling data was collected through a survey amongst mixed …


Digital Commons powered by bepress