Hydraulic Engineering Commons^™

Impact Characteristics Of Free Over-Fall In Pool Zone With Upstream Bed Slope, Shi-I Liu, Jen-Yan Chen, Yao-Ming Hong, Hung-Shin Huang, Rajkumar V Raikar

Journal of Marine Science and Technology–Taiwan

This paper presents the theoretical equations for the impact characteristics of free over-fall (ICFOF) in the pool zone with sloping upstream bed. The various impact characteristics considered are the brink depth, the impact position and impact angle, the tail water depth and the depth of water pool. In order to overcome the complexity in determining the ICFOF, they were expressed in dimensionless forms as functions of upstream bed slope (UBS), upstream Froude number and Drop number. The multiple regression analysis was used to obtain the empirical expressions for the ICFOF using the laboratory experimental results. It was found that the …

A Wind-Derived Upwelling Index For Lake Michigan, Stephen B. Davis, Rebecca Essig, Cary Troy

The Summer Undergraduate Research Fellowship (SURF) Symposium

Coastal upwelling is a phenomenon that occurs along coastlines throughout the world, and has been shown to be strongly correlated with large fish populations in these areas. Coastal upwelling occurs when strong coastal winds drive water transport away from the coast, causing colder, often nutrient-rich water to upwell in its place. While coastal upwellings can be detected with satellite imagery or in situ temperature measurements, these datasets are neither continuous nor long-term. A wind-derived upwelling index was created for Lake Michigan to continuously quantify upwellings over multiple decades, and to allow for further understanding of the impact of upwelling in …

Dynamic Testing Of An Elevated Water Tank, Alexander Michael Font

Graduate Theses and Dissertations

The objective of this thesis was to identify the modal properties of a pedesphere type, elevated water tank under different operating conditions relating to the water level in the tank. The research that was conducted included both numerical and experimental components. The numerical components consisted of a simple hand calculation to identify the fundamental frequency as well as numerical computer models to identify the natural frequencies and mode shapes for the first three bending modes. The experimental components consisted of characterizing the vibration of the elevated water tank in its current environment through ambient vibration testing.

Estimating Potential Water Pump Reductions Based On Soil Water Content, Geospatial Data Layers, And Variable Rate Irrigation (Vri) Pivot Control Resolution, Keith A. Miller

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Increasing concern for sustainable water use has the agriculture industry working toward higher efficiency use of irrigation water. The average irrigation water use efficiency throughout the United States is 45%, which is extremely poor. Advancements in crop management have continued to allow producers to know more about the conditions in their field from nutrient management and pest control, to understanding yield spatially.

Recent mechanical advancements have improved the capabilities of center pivot irrigation systems to water various depths throughout the field. This technology is known as variable rate irrigation (VRI). With VRI comes a whole new strategy for irrigation. Advancements …

Infiltration And Runoff Parameters For Tilled And No-Till Row Crops, Andrew J. Volkmer

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Infiltration and runoff are hydrologic processes that effect the amount of water available to plants, for groundwater recharge, and for stream flow. No-till planting (NT) is a management practice used to reduce soil erosion, increase water infiltration, and reduce soil water evaporation, and can have great impact on infiltration and runoff. An investigation was conducted to determine the impact of NT on infiltration and runoff when compared to tilled conditions.

Runoff and precipitation data was gathered from sites at Fillmore County, NE, Phelps County, NE, the USDA-ARS North Appalachian Experimental Watersheds (NAEW) near Coshocton, OH, and the Lennoxville Research Station …

Informing Flood Plain Wetland Restoration Using Amphibian Monitoring, Ashley Vanderham

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

Wetlands are among the most important and complex ecosystems in the world. They contribute to nutrient cycling, the hydrologic cycle, and provide critical habitat for many plants, fish, and wildlife. Channelization of Missouri River resulted in the loss of many floodplain wetlands. Despite ongoing restoration efforts, there are few ecologically-based performance guidelines, and managers need methods to quantify and assess the success of restored riverine wetland systems.

In 2008 a multi-institutional herpetofauna monitoring project, funded by the U.S. Army Corps of Engineers, was initiated in four states (Kansas, Missouri, Iowa, and Nebraska). The main goal of the project is to …

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

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

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

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

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 …

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

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

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

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

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

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

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

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 …

Hypothesis Testing For Management: Evolving And Answering Closed Questions Using Multiobjective Visualization, Joseph Kasprzyk, Joseph Guillaume, Joshua Kollat, Chris Danilo

International Congress on Environmental Modelling and Software

In order to use models to understand deeply uncertain future conditions, managers must be able to pose and test hypotheses about their management problems. In Iterative Closed Question Methodology (ICQM), a series of closed questions are used to structure thinking about hypotheses while looking beyond a problem's existing modeling representation. Our research is exploring how ICQM can contribute to a framework called Many Objective Robust Decision Making (MORDM), which uses multiobjective optimization and ensembles of uncertain future states of the world to create and evaluate robust solutions for environmental management. A visualization software tool; AeroVis, has greatly aided implementation of …