Download or read book Modeling Vernal Pool Hydrologic Regimes and Assessing Thier Sensitivity to Climatic and Land use Change written by Christopher R. Pyke and published by . This book was released on 2002 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrologic and Vegetative Modeling of Vernal Pools in the Sierra Nevada written by Ashton Montrone and published by . This book was released on 2013 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vernal pools are ephemeral wetlands that exist in local geographic depressions with relatively impermeable substrates. Vernal pools are typically filled with water primarily from direct precipitation in the winter and spring months and are dried because of evaporation and seepage in the summer and fall months. The unusual hydrology of vernal pools has led to unique species compositions within the pool as few plant species can tolerate the hydrologic extremes found in vernal pools. Of the roughly 100 different species of plants often found in California vernal pools, 90% are native and 55% are endemic to California. Land use changes and climate change threaten vernal pools. Understanding the impacts of climate change to vernal pool hydrology and the plant community will be important for managing these sensitive ecosystems. Previous vernal pool modeling efforts have been limited to hydrologic quantification while qualitatively discussing the impacts to vegetation. Creating coupled hydrologic and vegetative models is critical to quantitatively understanding impacts to vernal pool vegetation. A mass balance hydrologic model was created that uses precipitation and temperature as climate inputs and generates a pool stage time-series as an output. Three vegetation models were created from an existing plant community classification system. The vegetation models use the pool stage time-series from the hydrologic model to estimate a vegetative community distribution within the pool. Bias-corrected data from three global climate models (GCM) were used as climate inputs for coupled models of vernal pool hydrology and plant community distribution. Climate data from the years 1991-2000 and 2091-2100 for the A2 and B1 emission scenarios from each GCM were used. Changes in plant communities were compared between the 1991-2000 and 2091-2100 time segments for each emission scenario. The hydrologic model results indicate that predicted average annual maximum depth in 2091-2100 did not significantly differ from current conditions under either the A2 or B1 emission scenario. Hydroperiod was predicted to significantly decrease under the A2 scenario, but not under the B1 scenario. Vegetative model results indicate that the pool area containing plant communities associated with vernal pool specialists decreased under the A2 and B1 emission scenarios with the decrease more pronounced under the A2 scenario. Overall, the study indicates that creating coupled hydrologic and vegetation models for vernal pools provide insight on potential impacts of hydrology and climate change on vernal pool plant communities, but models of sensitive hydrologic systems like vernal pools require climate data with high spatial and temporal resolution.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2003 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seasonal Hydrologic Dynamics Under Changing Climate Land Use land Cover and Human Influence written by Namrata Batra and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Climatic changes along with the land use-land cover changes (LULCC) and human impacts significantly modify the hydrologic flow regime of the river basins, affecting water resources and environment from regional to global scale. Aided by satellite data, modeling and understanding of the interactions between physical and human systems, more reliable regional LULCC and climate change projections are now available. However, resulting quantitative projection of changes on the hydrologic components at the seasonal time scale are sparse. This study attempts to quantify the hydrologic response in different hydro-climatic regions of the world at the seasonal time scale in the context of the projected LULCC and climate change assessed through Intergovernmental Panel on Climate Change (IPCC) A1B emission scenario. The Common Land Model (CLM) is used as the hydrologic model for the study since it incorporates detailed physical process representation, uses physical parameterization without the need for calibration and can be run at relatively high spatial and temporal resolutions. A coupled modeling framework is applied to assess human water use impact on hydrologic discharge at the river basin scale by coupling of CLM to the Water Availability and Supply Model (WASM). A consistent global GIS based dataset is constructed for the Surface Boundary Conditions (SBCs) and meteorological forcing of the model. European Center for Medium Range Weather Forecasts (ECMWF) reanalysis data at 6-hour time step for the period 1976 through 2000 is used for meteorological forcing. The model results are validated using the observed discharge data from Global Runoff Distribution Center (GRDC). The ability of the hydrologic model to capture the dominant runoff processes at multiple time scales of interaction of the processes is explored using wavelet analysis. Future climate change projections are derived from the Fourth Assessment Report of IPCC based on the multi-model ensembles of projections. An Integrated Model to Assess the Global Environment (IMAGE), developed by the Netherlands Environmental Assessment Agency is used for LULCC data. The study is performed over nine river basins selected from Asia, Africa and North America to represent the broad climatic, landscape and human controls on the seasonal hydrological dynamics, and to assess how these controls differ for basins lying in different hydro-climatic regions. It is observed for all the study basins that small changes in the precipitation lead to much larger changes in the runoff response. The analysis reveals that certain regions (Orange and Volta basins in Africa) have seasons which are highly likely to experience significant reduction in future runoff while there are other regions (Ganges, Krishna and Huai basins in Asia) which have seasons very likely to experience increased runoff. These seasonal differences reflect the changes in water availability, which may not be known through annual estimates. Moreover, different aspects of human interferences are observed over each of the study basins. Comparison and quantification of such differences in the hydrologic components are of particular importance for the water resource managers and policy makers.
Download or read book Frameworks for Assessing Climate Change Impacts on Water Resources written by Ali Mehran and published by . This book was released on 2015 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerous studies have highlighted that water resources and hydrologic extremes are sensitive to climate change. An interesting research question is what the role of climate change is in occurrence of extreme events. More importantly, how climate extremes may change under future climate conditions and emission scenarios. Therefore, there exists a strong need to study water resources and hydrologic cycle under different climate change scenarios at the global scale. In the past decades, numerous methods and models have been developed for assessing climate change impacts on water resources. However, there are still major research gaps from uncertainties in climate model simulations to limitations in the current large scale water cycle (or global hydrologic) models. Some of the current research gaps include: (I) high uncertainty of climate model simulations; (II) limitations and high uncertainties of the global hydrologic model simulations because of calibration challenges at the global scale; and (III) lack of frameworks for accounting for the local resilience and man-made infrastructure in climate impact assessment studies. The overarching goal of this study is to address the above mentioned research gaps. In this dissertation, several novel evaluation metrics are introduced that can be used for evaluation of errors and biases in input data which is a key factor in the overall uncertainty of climate change studies. Furthermore, this study leads to a better representation of the hydrologic cycle at the global scale through a comprehensive multi-objective calibration framework for global hydrologic models. Then, a modeling framework is presented for accounting for local resilience in climate change studies. Finally, this study outlines a framework for combining top-down and bottom-up approaches for climate change impact assessment.
Download or read book 2D Hydrodynamic Modeling for Evaluating Restoration Potential of a Vernal Pool Complex written by Anna Franciska Fryjoff-Hung and published by . This book was released on 2018 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vernal pool landscapes are rare and highly modified. The Merced Vernal Pools and Grassland Reserve consists of 6,500 protected acres, preserving sensitive vernal pool habitat and organisms. The Reserve contains a number of modified stock ponds that have caused extensive alteration of the historic landscape to capture and retain water for longer periods than the seasonal wetland complexes dispersed throughout the site. Using a combination of empirical data and 2D hydrodynamic modeling, our project seeks to better understand how water moves throughout the UC Merced Vernal Pools and Grassland Reserve in order to evaluate the feasibility of potential hydrological restoration activities and develop a better understanding of potential management strategies. This study aims to assess the feasibility of restoring or enhancing existing natural vernal pool complexes through increased inundation by reconnecting historical channels via small alterations in previously modified terrain. A 2D hydrodynamic model was developed using HEC-RAS rain-on-grid methodology to assess the restorative potential of a vernal pool complex at Avocet Pond in the Merced Vernal Pools and Grassland Reserve. In this currently modified system, levees disconnect natural channels and reroute overland flows into the stock pond which behaves as a reservoir, removing water from downstream landscape processes. Increased inundation to natural habitats benefits native vernal pool species whose life histories are integrally tied to finite and variable hydroperiods. Invasive plant and animal species may be reduced through the reduction of perennial stock pond hydroperiods and increased inundation and hydrologic connectivity of wetland features. Base case hydroecological conditions were established as the formative basis for evaluating the benefit of various restoration scenarios. Proposed restoration scenarios implemented simple terrain modifications such as small breaks in conveyance levees or notching stock pond berms. Model simulations suggest that historical flow paths can be reconnected through minimal terrain alteration resulting in increased inundation to wetlands and other downstream environments and reduction of overall stock pond inflows and hydroperiod. Results of this study will serve as a demonstration of landscape scale restoration of a vernal pool grassland habitat that has been altered through past land uses so that similar restoration assessment methodology can be implemented on other preserved lands in the state.
Download or read book Assessment of Convergence in Habitat Function Flora and Vegetation of Created and Natural Vernal Pools written by Virginia C. Meyer and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Vernal pools are ephemeral wetlands that form in depressions underlain with soils that include a water-restricting horizon. These depressions fill with water during the winter in Mediterranean-type climates, and then rapidly dry during the late spring. Vernal pools are diminished in California, due to habitat loss from land-use conversion. The biota endemic to vernal pool habitats includes many rare and endangered species. Creation of vernal pools has been used as mitigation since the mid 1980s. Whether creation can reliably result in vernal pools with the range of biotic characteristics found in natural vernal pools remains unclear. Evaluation of created vernal pool attributes that reflect ecological function over the long-term is needed to inform management of existing mitigation projects and the planning of future projects. The vegetation, hydrology, soils, and plant communities of created vernal pools were compared with natural vernal pools at three mitigation sites in the Great Valley of California that differed in climate and substrate. Vegetation attributes and parameters of hydrologic regime were measured in the first years following construction, and again when the created pools at each site were 12-14 years old. Soil samples were taken during the last year of the study to assess basic soil characteristics. Finally, plant communities of created vernal pools were identified during the last two years of the study period and compared with natural vernal pool communities. The values of vernal pool species attributes increased with increasing maximum water depth and period of inundation. Fluctuations and downward trends in the values of vernal pool species attributes correlated with increased exotic species cover, and exotic species cover was highest in years of lowest annual precipitation. Trends of decreasing maximum water depth, inundation period, and vernal pool species cover, as well as increasing exotic species cover, correlated with release from cattle grazing at two sites. At a third site where light-to-moderate grazing occurred, vernal pools species attributes of created pools matched or were higher than those of natural pools, and maximum water depth was higher in created than in natural pools throughout the study period. Thus, grazing may be of primary importance in the ability of created vernal pools to maintain hydrologic function and vernal pool species attributes over the long-term. Soil texture, color, bulk density, and redox concentrations did not differ between created and natural pools. However, differences in soil pH and depth to hardpan were found between created and natural vernal pools. Natural vernal pool plant communities were found in created pools at two sites, but were those of deeper, longer-inundated habitats compared to the natural pools on-site. This may lead to a greater proportion of deeper, longer-inundated vernal pool habitats over time with continued use of creation as mitigation. Only one natural vernal pool community was identified at one site, where most created pools supported exotics-dominated, non-wetland communities. Site characteristics and management practices of mitigation projects lead to differences in outcomes in ecological function in created vernal pools.
Download or read book American Doctoral Dissertations written by and published by . This book was released on 2002 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecological Society of America Annual Meeting Abstracts written by Ecological Society of America. Meeting and published by . This book was released on 2002 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of the Impact of Climate Variability on Modelling Hydrological Response Hak Soo Kim written by Hak-Soo Kim and published by . This book was released on 2010 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conceptual rainfall-runoff models are increasingly being proposed as important tools for water resource prediction, and in particular for assessing the impacts of climate and land use changes on catchment hydrology. But there are many issues that must be addressed in order to avoid adverse effects from model complexity, over-parameterisation and limited data. A model's ability to capture the effect of climate variability is obviously one of the most important issues for addressing modelling capacity to identify the impacts of climate and land use changes. The main objective of this thesis is to provide an assessment framework to evaluate model adequacy in representing the impacts of climate variability on streamflow. This includes various techniques for reducing predictive uncertainty arising from data and model calibration. The methodology employed in the thesis is primarily based on a combination of data- and model-based analysis.
Download or read book Understanding and Assessing Climate Change written by Deborah J. Bathke and published by . This book was released on 2014-09 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thriving on Our Changing Planet A Decadal Strategy for Earth Observation from Space written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-06-18 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: We live on a dynamic Earth shaped by both natural processes and the impacts of humans on their environment. It is in our collective interest to observe and understand our planet, and to predict future behavior to the extent possible, in order to effectively manage resources, successfully respond to threats from natural and human-induced environmental change, and capitalize on the opportunities â€" social, economic, security, and more â€" that such knowledge can bring. By continuously monitoring and exploring Earth, developing a deep understanding of its evolving behavior, and characterizing the processes that shape and reshape the environment in which we live, we not only advance knowledge and basic discovery about our planet, but we further develop the foundation upon which benefits to society are built. Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space (National Academies Press, 2018) provides detailed guidance on how relevant federal agencies can ensure that the United States receives the maximum benefit from its investments in Earth observations from space, while operating within realistic cost constraints. This short booklet, designed to be accessible to the general public, provides a summary of the key ideas and recommendations from the full decadal survey report.
Download or read book Flowering Plants Monocotyledons written by Klaus Kubitzki and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: When Rolf Dahlgren and I embarked on preparing this book series, Rolf took prime responsibility for monocotyledons, which had interested him for a long time. After finishing his comparative study and family classification of the monocots, he devoted much energy to the acquisition and editing of family treatments for the present series. After his untimely death, Peter Goldblatt, who had worked with him, continued to handle further incoming monocot manuscripts until, in the early 1990s, his other obligations no longer allowed him to continue. At that time, some 30 manuscripts in various states of perfection had accumulated, which seemed to form a solid basis for a speedy completion of the FGVP monocots; with the exception of the grasses and orchids which would appear in separate volumes. I felt a strong obligation to do everything to help in publishing the manuscripts that had been put into our hands. I finally decided to take charge of them personally, although during my life as a botainst I had never seriously been interested in monocots.
Download or read book Climate Change and Water written by Intergovernmental Panel on Climate Change / Working Group Technical Support Unit and published by . This book was released on 2008 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Technical Paper addresses the issue of freshwater. Sealevel rise is dealt with only insofar as it can lead to impacts on freshwater in coastal areas and beyond. Climate, freshwater, biophysical and socio-economic systems are interconnected in complex ways. Hence, a change in any one of these can induce a change in any other. Freshwater-related issues are critical in determining key regional and sectoral vulnerabilities. Therefore, the relationship between climate change and freshwater resources is of primary concern to human society and also has implications for all living species. -- page vii.
Download or read book Ecosystems of California written by Harold Mooney and published by Univ of California Press. This book was released on 2016-01-19 with total page 1008 pages. Available in PDF, EPUB and Kindle. Book excerpt: This long-anticipated reference and sourcebook for CaliforniaÕs remarkable ecological abundance provides an integrated assessment of each major ecosystem typeÑits distribution, structure, function, and management. A comprehensive synthesis of our knowledge about this biologically diverse state, Ecosystems of California covers the state from oceans to mountaintops using multiple lenses: past and present, flora and fauna, aquatic and terrestrial, natural and managed. Each chapter evaluates natural processes for a specific ecosystem, describes drivers of change, and discusses how that ecosystem may be altered in the future. This book also explores the drivers of CaliforniaÕs ecological patterns and the history of the stateÕs various ecosystems, outlining how the challenges of climate change and invasive species and opportunities for regulation and stewardship could potentially affect the stateÕs ecosystems. The text explicitly incorporates both human impacts and conservation and restoration efforts and shows how ecosystems support human well-being. Edited by two esteemed ecosystem ecologists and with overviews by leading experts on each ecosystem, this definitive work will be indispensable for natural resource management and conservation professionals as well as for undergraduate or graduate students of CaliforniaÕs environment and curious naturalists.
Download or read book Wetland Ecosystems written by William J. Mitsch and published by John Wiley & Sons. This book was released on 2009-04-13 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: New focused text introduces readers to wetland ecosystems and systems approaches to studying wetlands With its comprehensive coverage of wetland science, management, and restoration, Mitsch and Gosselink's Wetlands has been the premier reference on wetlands for more than two decades. Now, the coverage of specific wetland ecosystem types from earlier editions of this acclaimed work has been updated, revised, and supplemented with additional content in order to create this new text focusing exclusively on wetland ecosystems. This book now complements Wetlands, Fourth Edition. Following an introduction to ecosystems in general and wetland ecosystems in particular, Wetland Ecosystems examines the major types of wetlands found throughout the world: coastal wetlands, freshwater marshes and forested swamps, and peatlands. The final chapter reviews three fundamental systems approaches to studying wetlands: mesocosms, full-scale experimental ecosystems, and mathematical modeling. This new text features: Updated descriptions of the hydrology, biogeochemistry, and biology of the main types of wetlands found in the world New content introducing general ecosystems, wetland ecosystems, whole ecosystem and mesocosm experiments with wetlands, and systems ecology and modeling A detailed description of the ecosystem services provided by wetlands A broad international scope, including many examples of wetlands located outside North America Two new coauthors offering new perspectives and additional insights into the latest ecosystem and modeling techniques An abundance of illustrations helps readers understand how different biological communities and the abiotic environment in wetland ecosystems interact and function. Tables and text boxes provide at-a-glance summaries of key information. Lastly, each chapter concludes with a list of recommended readings. This text has been designed as an introduction for students and professionals in wetland ecology and management, general ecology, environmental science, and natural resource management.
Download or read book Ecology Conservation and Management of Vernal Pool Ecosystems written by Carol W. Witham and published by . This book was released on 1998 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
