Physical Sciences and Mathematics Commons^™

Modeling Overdraft-Driven Nitrate Transport In Shallow Wells For Mitigation And Scenario Planning, Jonathan Cronk

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

In Nebraska, average nitrate concentrations in groundwater have doubled since 1974, making water quality management more important than ever. As droughts, heat waves, and floods become more common climate events, understanding their impacts will be necessary to make informed management decisions. Emerging literature describes that drought correlates to an increase in the concentration of nitrate-N at domestic and irrigation wells, however the relative contributions of the mechanisms thought to be responsible is currently unknown.

This research assessed the impact of recharge and pumping rate changes as two mechanisms affecting nitrate-N concentration during drought, assessed the relationship between well depth and …

Using Survey Data And Hec-Ras Modeling To Assess A Riffle-Remediation Structure On The Big River, Bonne Terre, Missouri, Nichole Renee Weedman

MSU Graduate Theses

Sediment transport and deposition in river channels can vary for many reasons including flooding, dredging, channel velocity, and grain size. On the Big River, the Army Corps of Engineers constructed a riffle ramp structure to trap and remediate lead-contaminated sediments. The performance of the structure is unknown. The goal of this study is to evaluate the storage capabilities of the riffle structure. To do this, survey data was collected to analyze sediment storage and entered into the HEC-RAS 5.0 to model the hydraulics of the channel before and after the riffle installation. Samples were collected to assess the level of …

Decision Support Tools To Address Climate Change: Climate Model - Land Surface Models, Zea Mays L. (Corn) Phenology And Evapotranspiration-Yield Sensitivity Models For Nebraska, Usa., Jane A. Okalebo

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

Nebraska's climate is highly variable and is expected to change in the future with anthropogenic global warming (AGW), resulting in warmer spring and summer temperatures coupled with more erratic rainfall events. This has strong implications for agriculture in the region, yet it is not clear that current modeling and decision-support tools are adequate to address these looming changes and provide planning, mitigation and adaptation strategies. To address climate change and its implications to agriculture in Nebraska, a set of robust decision support tools are very crucial. This study herein are divided into three chapters, with each chapter addressing a specific …

Determination Of Seasonal Crop Coefficients For The Cal Poly Campus Vineyard Using The “Paso Panel”, Daniel L. Vyenielo

Wine and Viticulture

Seasonal Crop Coefficients were determined using the "Paso Panel" during the summer of 2014 at the Cal Poly Trestle Vineyard in the Pinot and Syrah blocks.

Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson

Master's Theses

Packed-bed digesters are an alternative to covered lagoon digesters for methane production and anaerobic treatment of dilute wastewaters such as dairy barn flush water. The physical media of packed-beds retain biofilms, often allowing increased treatment rates. Previous studies have evaluated several types of media for digestion of dilute wastewaters, but cost and media fouling have setback commercial development. A major operational cost has been effluent recirculation pumping.

In the present effort, a novel approach to anaerobic digestion of flush dairy water was developed at pilot-scale: broken walnut shells were used as a low-cost packed-bed medium and effluent recirculation was replaced …

Optimized Use Of Water From Multiple Sources In Micro Water Grid Systems: A Modeling Approach, Hyeongrak Cho, Jungwoo Jung, Sangho Lee, Soo Kwen Chae

International Conference on Hydroinformatics

Micro water grid (MWG) is a novel approach to allow high reliability, diversification of water sources, low energy consumption, and cost reduction. Although it is not well-defined, it has potential for efficient management of urban water. MWG is suitable for use in small-scale buildings and towns, which have various uses of water produced from multiple source waters. Accordingly, design of MWG is challenging without proper tools to predict its performance. This research focused on the development and application of a model for optimized use of water from multiple sources in MWG systems. The model was comprised of two modules including …

Improving Sediment Transport Modelling By A Combination Of Field Data And Sensitivity Analysis, Tom Vanwalleghem, Juan Pablo Garcia, Juan Vicente Giráldez

International Conference on Hydroinformatics

Traditionally, the relationship between flow rate and sediment concentration in rivers has been estimated empirically. However, the problem of empirical data collection is that it is often difficult to cover the entire range of flow rates. Especially higher flow rates are often undersampled, which might lead to an underestimation of modelled sediment transport as flood events are often associated with important erosion events. In order to overcome this limitation, the introduction of the transport capacity concept can establish a safe upper bound of this sediment transport relationship. Nevertheless, given the number of implied variables in this equation, there is a …

A Dss For Reservoirs Operation Based On The Execution Of Formal Models, Antonio Linares, Jesus Regodon, Laura Panizo, Maria Del Mar Gallardo, Pedro Merino

International Conference on Hydroinformatics

Controlling the evolution of a reservoir in a flood episode can be critical, especially in Mediterranean basins where the concentration time is very short. In this situation, an automatic software tool can help the reservoir manager to make a quick decision. In this paper we present a DSS based on the execution of formal models by means of model checking. This technique exhaustively explores the different execution branches of a model of the system. The DSS addresses two flood control tasks. First, the DSS simulates the evolution of the reservoir (the water stored and released) when applying a predefined flood …

A Model To Structure Scientific Information For Decision Makers, Rebecca Kristine Schmidt, Damian Barrett, Simon Gallant

International Conference on Hydroinformatics

Scientific information for decision makers needs to be discoverable and transparent so that decisions are more easily based on scientific evidence. One way to achieve these goals is to specify a robust model that structures this scientific information. This paper presents a model that governs the scientific activities, inputs and products for bioregional assessments (BAs), which provide information on the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and coal mining development on water resources. This scientific information will be available for all interested parties …

Wrap Your Model!, Hauke Sonnenberg, Michael Rustler, Victor Philippon, Nicolas Caradot, Andreas Matzinger

International Conference on Hydroinformatics

Introduction Environmental models are often provided in the form of software solutions, with different levels of complexity. The simplest form is an executable file reading the model setup and boundary conditions from input files, doing the calculations and generating output files with model results. Preparing input files and reading output files requires to know and respect model specifics such as file formats and calling conventions. This "user-unfriendliness" may discourage the usage of models in this simplest form. However, these models may offer great opportunities since they are often freely available and contain the pure model "core" being fast in execution. …

Hydroclimatic Forecasting In The Western United States Using Paleoclimate Reconstructions And Data-Driven Models, Christopher Allen Carrier

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis investigated climate variability and their associated hydrologic responses in the western United States. The western United States faces the problem of water scarcity, where the management and mitigation of available water supplies are further complicated by climate variability. Climate variability associated with the phases of oceanic-atmospheric oscillations has been shown to influence streamflow and precipitation, where predictive relationships have led to the possibility of producing long-range forecasts. Based on literature review, four oceanic-atmospheric oscillation indices were identified in having the most prominent influence over the western United States including the El Niño - Southern Oscillation (ENSO), Pacific Decadal …

A Financial Impact Assessment Of Ld 1725: Stream Crossings, New England Environmental Finance Center, Muskie School Of Public Service

Water

This report looks at the potential financial impact of LD 1725 on the estimated 30,000 stream crossings in the State of Maine that would be affected by the law. Our research for this report included the analysis of nearly 2000 stream crossings and the data collection necessary for the development of extensive stream crossing replacement cost models. We found that the 1.2 bankfull requirements in LD 1725 would result in a 75% ‐ 250% increase in structure widths for stream crossing projects across the state. An upsize of this magnitude would increase the cost of replacing stream crossings statewide by …

A Financial Impact Assessment Of Ld 1725: Stream Crossings (Presentation), New England Environmental Finance Center, Muskie School Of Public Service

Water

This report looks at the potential financial impact of LD 1725 on the estimated 30,000 stream crossings in the State of Maine that would be affected by the law. Our research for this report included the analysis of nearly 2000 stream crossings and the data collection necessary for the development of extensive stream crossing replacement cost models. We found that the 1.2 bankfull requirements in LD 1725 would result in a 75% ‐ 250% increase in structure widths for stream crossing projects across the state. An upsize of this magnitude would increase the cost of replacing stream crossings statewide by …

Evaluation Of Satellite-Retrieved Extreme Precipitation Rates Across The Central United States, A. Aghakoucak, A. Behrangi, S. Sorooshian, K. Hsu, Eyal Amitai

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Water resources management, forecasting, and decision making require reliable estimates of precipitation. Extreme precipitation events are of particular importance because of their severe impact on the economy, the environment, and the society. In recent years, the emergence of various satellite-retrieved precipitation products with high spatial resolutions and global coverage have resulted in new sources of uninterrupted precipitation estimates. However, satellite-based estimates are not well integrated into operational and decision-making applications because of a lack of information regarding the associated uncertainties and reliability of these products. In this study, four satellite-derived precipitation products (CMORPH, PERSIANN, TMPA-RT, and TMPA-V6) are evaluated with …

Culvert Material Cost Comparison, New England Environmental Finance Center

Water

The following tables provide a detailed look at the role that culvert material and culvert diameter play in the overall cost of a culvert replacement project.

Construction Cost Models, Barry Dikeman

Economics and Finance

The following are a series of cost estimate models similar in format to a typical engineer’s estimate that were developed in support of our financial impact assessment report for LD 1725. The models us current material costs, labor costs, and equipment costs for the region to provide a comparative cost analysis of seven culvert replacement scenarios. The models provide information about what the cost impact of LD 1725 would be for typical culvert replacements in Maine. However, due to the inherent restrictions of the cost modeling framework we were not able to include the abundance of variables that would be …

The Future Of Mineral Development On Federal Lands In The United States, John D. Leshy

The Future of Natural Resources Law and Policy (Summer Conference, June 6-8)

11 pages.

Includes bibliographical references

"Outline of presentation of John D. Leshy, Harry D. Sunderland Distinguished Professor, U.C. Hastings College of the Law, Natural Resources Law center, June 7, 2007" (pp. 3-5)

"Leshy draft 4.27.07 For Natural Resources Law Center" (pp. 6-13)

The Development Of Relationships Between Constituent Concentrations And Generic Hydrological Variables, Carmen T. Agouridis, Dwayne R. Edwards

Biosystems and Agricultural Engineering Faculty Publications

The collection and analysis of samples from storm events constitutes a large portion of the effort associated with water quality research. Estimating concentrations or loads from these events is often difficult. The equipment necessary to analyze the samples and the required laboratory resources are typically significant expenses incurred by the researcher. One potential method to reduce these costs is through the development of generic relationships between concentrations and easily measured variables such as dimensionless flow rate or time. The benefits recognized from such an effort include a reduction in the number of required samples, resulting in a reduction in cost. …