Download or read book Toward A Comprehensive Water Quality Model For The Chesapeake Bay Using Unstructured Grids written by Xun Cai and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chesapeake Bay is one of the most productive ecosystems on the US east coast which supports various living resources and habitat, and therefore has significant impacts on human beings and ecosystem health. Developing the capability of accurately simulating the water quality condition in the Chesapeake Bay, such as seasonal hypoxia, phytoplankton production, and nutrient dynamics, helps to better understand the interactions of hydrodynamical and biochemical processes, and more importantly, to predict conditions under changing climate and human intervention. Currently, most Chesapeake Bay models use structured grids that lack the flexibility for local refinements to fit complex geometry over both large and small scales, which hampers the allocation of local TMDLs for shallow water and small tributaries. In addition, few of them extend their simulations beyond the water column state variables, such as dissolved oxygen and nutrients, to include other living resources such as vegetation. These limitations motivate the model developments in this dissertation of: (1) a new comprehensive water quality model using high-resolution unstructured grids, which possesses the cross-scale capability to study interactions among water bodies and processes of different scales; and (2) a tightly coupled tidal marsh model, which is linked to the water quality model for water column to study the interactions between the marshes and surrounding aquatic system. The new modeling tool can be effectively utilized as a powerful tool for adaptive management in the Chesapeake Bay and can also be exported to other estuaries in the world.In this dissertation, Chapter 2 focuses on the development of a high-resolution water quality model in the water column and sediment flux part of the water quality model. This part of this study also demonstrates the importance of the correct representation of geometry, and the detrimental effects of artificial bathymetry smoothing on model simulations. Chapter 3 of this dissertation studies the impacts of sea-level rise (SLR) on seasonal hypoxia and phytoplankton production in the Chesapeake Bay with the newly developed water quality model. SLR is predicted to increase the hypoxic volume in the Chesapeake Bay by altering the physical processes and enhancing the estuarine respirations. Phytoplankton production in the shallow shoals is also predicted to increase under SLR, as a result of increased light utilization. Chapter 4 of this dissertation focuses on developing a new marsh model in the hydrodynamic-water quality model framework. This new model extends the model coverage to the tidal wetlands which are periodically inundated. The tidal marshes are suggested to affect the estuarine oxygen, carbon, and nutrient dynamics through tidal exchange, e.g., contributing the diel DO cycle. Chapter 5 studies the impacts of SLR on the biochemical processes in the York River Estuary, a tributary of the Bay that has extensive tidal marshes, with the fully-coupled hydrodynamic-water quality-marsh model. The SLR is predicted to enhance the exchanges between the marshes and the adjacent channel, which in turn further impacts the estuarine biochemical processes.
Download or read book Use of Nutrient Balances in Comprehensive Watershed Water Quality Modeling of Chesapeake Bay written by Anthony S. Donigian and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this research was to improve the overall utility of the Chesapeake Bay Watershed Model, based on the U.S. Environmental Protection Agency Hydrologic Simulation Program-Fortran model, as a planning tool for comprehensive watershed planning and assessment The Chesapeake Bay Watershed Model is a unique state of-the-art watershed modeling capability that includes detailed soil process simulation for agricultural areas, linked to an instream water quality and nutrient model capable of representing comprehensive point and nonpoint pollutant loadings for the entire 68,000 square mile drainage area of the Chesapeake Bay The specific improvements recommended and tasks performed in this effort included development of nutrient balances for nonagricultural land uses; testing of the application procedures for forest, pasture, and urban land uses; and application of the enhanced model to the Shenandoah Subbasin within the Chesapeake Bay watershed to assess load contributions and impacts of the model refinements. The real benefits of the current refinement phase of the Chesapeake Bay Program Watershed Model are realized from the extension of the nutrient balance approach to all major land use (except urban, in the simulations) and the utility of this approach for nutrient management.
Download or read book Use of Nutrient Balances in Comprehensive Watershed Water Quality Modeling of Chesapeake Bay written by Anthony S. Donigian and published by . This book was released on 1998 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this research was to improve the overall utility of the Chesapeake Bay Watershed Model, based on the U.S. Environmental Protection Agency Hydrologic Simulation Program-Fortran model, as a planning tool for comprehensive watershed planning and assessment The Chesapeake Bay Watershed Model is a unique state of-the-art watershed modeling capability that includes detailed soil process simulation for agricultural areas, linked to an instream water quality and nutrient model capable of representing comprehensive point and nonpoint pollutant loadings for the entire 68,000 square mile drainage area of the Chesapeake Bay The specific improvements recommended and tasks performed in this effort included development of nutrient balances for nonagricultural land uses; testing of the application procedures for forest, pasture, and urban land uses; and application of the enhanced model to the Shenandoah Subbasin within the Chesapeake Bay watershed to assess load contributions and impacts of the model refinements. The real benefits of the current refinement phase of the Chesapeake Bay Program Watershed Model are realized from the extension of the nutrient balance approach to all major land use (except urban, in the simulations) and the utility of this approach for nutrient management.
Download or read book Refinement of a Comprehensive Watershed Water Quality Model with Application to the Chesapeake Bay Watershed written by Anthony S. Donigian and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this research work was to improve the overall utility of the Chesapeake Bay Watershed Model, based on the U.S. Environmental Protection Agency Hydrologic Simulation Program-Fortran (HSPF) model, as a planning tool for comprehensive watershed planning and assessment The specific improvements recommended and tasks performed in this effort included refinement of the agricultural (AGCHEM) module simulation to better represent plant uptake impacts of agricultural practices and nutrient management scenarios, testing the AGCHEM refinements, applying the refined AGCHEM to selected subbasins of the Chesapeake Bay drainage, and recalibrating the refined Watershed Model to the selected subbasins.
Download or read book Water Quality Conditions in Chesapeake Bay Using Model Results written by Arthur J. Butt and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Refinement of a Comprehensive Watershed Water Quality Model with Application to the Chesapeake Bay Watershed written by Anthony S. Donigian and published by . This book was released on 1998 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this research work was to improve the overall utility of the Chesapeake Bay Watershed Model, based on the U.S. Environmental Protection Agency Hydrologic Simulation Program-Fortran (HSPF) model, as a planning tool for comprehensive watershed planning and assessment The specific improvements recommended and tasks performed in this effort included refinement of the agricultural (AGCHEM) module simulation to better represent plant uptake impacts of agricultural practices and nutrient management scenarios, testing the AGCHEM refinements, applying the refined AGCHEM to selected subbasins of the Chesapeake Bay drainage, and recalibrating the refined Watershed Model to the selected subbasins.
Download or read book Comprehensive Water Quality Project Chesapeake Bay Susquehanna River Basins written by United States Environmental Protect Epa and published by . This book was released on 2019-07-03 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Water Quality Project Chesapeake Bay Susquehanna River Basins
Download or read book Chesapeake Bay Water Quality Modeling written by Virginia. State Water Control Board. Chesapeake Bay Office and published by . This book was released on 1991 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Work Plan for Three dimensional Time varying Hydrodynamic and Water Quality Model of Chesapeake Bay written by and published by . This book was released on 1988 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the Work Plan for development of a three-dimensional, time-varying, hydrodynamic and water quality model for Chesapeake Bay. The Chesapeake Bay Program is a cooperative effort between state and Federal agencies to restore the health and productivity of America's largest estuary. The report describes the technical work tasks, schedules, and study management. The developed hydrodynamic and water quality model will be an important component in the development of a strategy to address specific management issues. (fr).
Download or read book Using Water Quality Models in Management a Multiple Model Assessment Analysis of Confidence and Evaluation of Climate Change Impacts written by Issac David Irby and published by . This book was released on 2017 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human impacts on the Chesapeake Bay through increased nutrient run-off as a result of land-use change, urbanization, and industrialization, have resulted in a degradation of water quality over the last half-century. These direct impacts, compounded with human-induced climate changes such as warming, rising sea-level, and changes in precipitation, have elevated the conversation surrounding the future of water quality in the Bay. The overall goal of this dissertation project is to use a combination of models and data to better understand and quantify the impact of changes in nutrient loads and climate on water quality in the Chesapeake Bay. This research achieves that goal in three parts. First, a set of eight water quality models is used to establish a model mean and assess model skill. All models were found to exhibit similar skill in resolving dissolved oxygen concentrations as well as a number of dissolved oxygen-influencing variables (temperature, salinity, stratification, chlorophyll and nitrate) and the model mean exhibited the highest individual skill. The location of stratification within the water column was found to be a limiting factor in the models’ ability to adequately simulate habitat compression resulting from low-oxygen conditions. Second, two of the previous models underwent the regulatory Chesapeake Bay pollution diet mandated by the Environmental Protection Agency. Both models exhibited a similar relative improvement in dissolved oxygen concentrations as a result of the reduction of nutrients stipulated in the pollution diet. A Confidence Index was developed to identify the locations of the Bay where the models are in agreement and disagreement regarding the impacts of the pollution diet. The models were least certain in the deep part of the upper main stem of the Bay and the uncertainty primarily stemmed from the post-processing methodology. Finally, by projecting the impacts of climate change in 2050 on the Bay, the potential success of the pollution diet in light of future projections for air temperature, sea level, and precipitation was examined. While a changing climate will reduce the ability of the nutrient reduction to improve oxygen concentrations, that effect is trumped by the improvements in dissolved oxygen stemming from the pollution diet itself. However, climate change still has the potential to cause the current level of nutrient reduction to be inadequate. This is primarily due to the fact that low-oxygen conditions are predicted to start one week earlier, on average, in the future, with the primary changes resulting from the increase in temperature. Overall, this research lends an increased degree of confidence in the water quality modeling of the potential impact of the Chesapeake Bay pollution diet. This research also establishes the efficacy of utilizing a multiple model approach to examining projected changes in water quality while establishing that the pollution diet trumps the impact from climate change. This work will lead directly to advances in scientific understanding of the response of water quality, ecosystem health, and ecological resilience to the impacts of nutrient reduction and climate change.
Download or read book Calibrating the Chesapeake Bay Water Quality Model written by C. F. Cerco and published by . This book was released on 1989 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Total Maximum Daily Load Analysis and Modeling written by American Society of Civil Engineers. TMDL Analysis and Modeling Task Committee and published by Asce American Society of Civil Engineers Ewri. This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report reviews more than 35 TMDL models and procedures for estimating the maximum amount of a pollutant that a water body can receive and still meet applicable water quality standards.
Download or read book Environmental education in the schools creating a program that works written by and published by DIANE Publishing. This book was released on with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Onsite Wastewater Treatment Systems Manual written by and published by . This book was released on 2002 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This manual contains overview information on treatment technologies, installation practices, and past performance."--Introduction.
Download or read book Coastal Ecosystems in Transition written by Thomas C. Malone and published by John Wiley & Sons. This book was released on 2020-12-17 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explores how two coastal ecosystems are responding to the pressures of human expansion The Northern Adriatic Sea, a continental shelf ecosystem in the Northeast Mediterranean Sea, and the Chesapeake Bay, a major estuary of the mid-Atlantic coast of the United States, are semi-enclosed, river-dominated ecosystems with urbanized watersheds that support extensive industrial agriculture. Coastal Ecosystems in Transition: A Comparative Analysis of the Northern Adriatic and Chesapeake Bay presents an update of a study published two decades ago. Revisiting these two ecosystems provides an opportunity to assess changing anthropogenic pressures in the context of global climate change. The new insights can be used to inform ecosystem-based approaches to sustainable development of coastal environments. Volume highlights include: Effects of nutrient enrichment and climate-driven changes on critical coastal habitats Patterns of stratification and circulation Food web dynamics from phytoplankton to fish Nutrient cycling, water quality, and harmful algal events Causes and consequences of interannual variability The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals. Read a review of this book in Marine Ecology review of this book
Download or read book Sediment Flux Modeling written by Dominic M. DiToro and published by John Wiley & Sons. This book was released on 2001-01-16 with total page 657 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents mathematical models for estimating and predicting sediment fluxes. * Models provide sufficient detail and data to enable scientists in the field to reproduce the computations and use the models for understanding their own data. * Provides computations directly applicable to developing modern water quality models. * All models have been calibrated and verified using three large data sets.
Download or read book Aquaculture Situation and Outlook Report written by and published by . This book was released on 1992 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
