Download or read book Improving Climate Projections Through the Assessment of Model Uncertainty and Bias in the Global Water Cycle written by Noel C. Baker and published by . This book was released on 2013 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The implications of a changing climate have a profound impact on human life, society, and policy making. The need for accurate climate prediction becomes increasingly important as we better understand these implications. Currently, the most widely used climate prediction relies on the synthesis of climate model simulations organized by the Coupled Model Intercomparison Project (CMIP); these simulations are ensemble-averaged to construct projections for the 21st century climate. However, a significant degree of bias and variability in the model simulations for the 20th century climate is well-known at both global and regional scales. Based on that insight, this study provides an alternative approach for constructing climate projections that incorporates knowledge of model bias. This approach is demonstrated to be a viable alternative which can be easily implemented by water resource managers for potentially more accurate projections. Tests of the new approach are provided on a global scale with an emphasis on semiarid regional studies for their particular vulnerability to water resource changes, using both the former CMIP Phase 3 (CMIP3) and current Phase 5 (CMIP5) model archives. This investigation is accompanied by a detailed analysis of the dynamical processes and water budget to understand the behaviors and sources of model biases. Sensitivity studies of selected CMIP5 models are also performed with an atmospheric component model by testing the relationship between climate change forcings and model simulated response. The information derived from each study is used to determine the progressive quality of coupled climate models in simulating the global water cycle by rigorously investigating sources of model bias related to the moisture budget. As such, the conclusions of this project are highly relevant to model development and potentially may be used to further improve climate projections.
Download or read book Essays on the Quantification and Propagation of Uncertainty in Climate Change Impact Assessments for Water Resource Systems written by Scott Steinschneider and published by . This book was released on 2014 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sustainable water resources planning and management under climate change requires a proper treatment of uncertainties that emerge in an impacts analysis. A primary source of this uncertainty originates from the difficulties in projecting how anthropogenic greenhouse gas emissions will evolve over time and influence the climate system at regional and local scales. However, other sources of uncertainty, such as errors in modeling hydrologic response to climate and the influences of internal climate variability, compound the effects of climate change uncertainty and further obscure our understanding of water resources performance under future climate conditions. This work presents an approach to quantify the interactions, propagation, and relative contributions of different sources of uncertainty in a water resources impacts assessment under climate change. Hydrologic modeling uncertainty is addressed using Bayesian methods that can quantify both parametric and structural errors. Hydrologic uncertainties are propagated through an ensemble of climate projections to explore their joint uncertainty. A new stochastic weather generator is presented to develop a wide ensemble of climate projections that can extend beyond the limited range of change often afforded by global climate models and better explore climate risks. The weather generator also enables the development of multiple realizations of the same mean climate conditions, allowing an exploration of the effects of internal climate variability. The uncertainties from mean climate changes, internal climate variability, and hydrologic modeling errors are then integrated in two climate change analyses of a flood control facility and a multi-purpose surface reservoir system, respectively, to explore their separate and combined effect on future system performance. The primary goal of this work is to present methods that can better estimate the precision associated with future projections of water resource system performance under climate change, and through this provide information that can guide the development of adaptation strategies that are robust to these uncertainties.
Download or read book New techniques for improving climate models predictions and projections written by Matthew Collins and published by Frontiers Media SA. This book was released on 2022-01-24 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modelling the Impact of Climate Change on Water Resources written by C. Fai Fung and published by John Wiley & Sons. This book was released on 2010-12-01 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: The quantitative assessment of the impact of climate change on water availability and water resources management requires knowledge of climate, hydro(geo)logical and water resources models, and particularly the relationships between each of them. This book brings together world experts on each of these aspects, distilling each complex topic into concise and easy to understand chapters, in which both the uses and limitations of modelling are explored. The book concludes with a set of case studies using real-life examples to illustrate the steps required and the problems that can be faced in assessing the potential impacts of climate change on water resource systems. For students, scientists, engineers and decision-makers alike, this book provides an invaluable and critical look at the information that is provided by climate models, and the ways it is used in modelling water systems. A key focus is the exploration of how uncertainties may accrue at each stage of an impacts assessment, and the reliability of the resulting information. The book is a practical guide to understanding the opportunities and pitfalls in the quantitative assessment of climate change impacts and adaptation in the water resource sector.
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 Climatic Change Implications for the Hydrological Cycle and for Water Management written by Martin Beniston and published by Springer Science & Business Media. This book was released on 2006-04-11 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: year simulations in order to separate noise in the system from the climate change signal. Several contributing papers focused on case studies using Regional Climate Models (RCMs) linked to hydrological models, applied to the analysis of runoff under conditions of convective activity and extreme precipitation, in regions of complex topography, or stakeholder-driven investigations such as water runoff simulations in Quebec undertaken for a major utility. Thorough analyses of GCM results for the Century were reported at the Workshop, in order to illustrate the improvements in model results which have taken place in recent years, and the increasing confidence with which the models can be used for projecting climatic change in coming decades. However, there is still much room for improvement; there is also a need to address more fully the manner in which climate and impacts models (e. g. , hydrological models) can be linked, in terms of consistency and the overlap between different scales, the underlying physical assumptions, and the parameterizations used. Session 2 was devoted to the two extremes of water resources, namely floods and droughts, the focus here being to identify the climate change component in river floods. These have significant economic implications, as was shown by several scientists from Western and Central Europe. Many long time series have been studied worldwide with the aim of detection of nonstationarities, yet there is no conclusive evidence of climate-related changes in flow records, in general.
Download or read book Climate Change Projection and Time varying Multi dimensional Risk Analysis written by Ali Sarhadi and published by . This book was released on 2016 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent decades, population growth and global warming consequent to greenhouse gas emissions because of human activities, has changed the atmospheric composition leading to intensifying extreme climate phenomena and overall increase of extreme events. These extreme events have caused human suffering and devastating effects in recent record-breaking warming years. To mitigate adverse consequences arising from global warming, the best strategy is to project the future probabilistic behavior of extreme climate phenomena under changing environment. The first contribution of this research is to improve the predictive power of regression-based statistical downscaling processes to accurately project the future behavior of extreme climate phenomena. First, a supervised dimensionality reduction algorithm is proposed for the statistical downscaling to derive a low-dimensional manifold representing climate change signals encoding of high-dimensional atmospheric variables. Such an algorithm is novel in climate change studies as past literature has focused on deriving low-dimensional principal components from large-scale atmospheric projectors without taking into account the target hydro-climate variables. The new algorithm called Supervised Principal Component analysis (Supervised PCA) outperforms all of the existing state-of-the-art dimensionality reduction algorithms. The model improves the performance of the statistical downscaling modelling through deriving subspaces that have maximum dependency with the target hydro-climate variables. A kernel version of Supervised PCA is also introduced to reduce nonlinear dimensionality and capture all of the nonlinear and complex variabilities between hydro-climate response variable and atmospheric projectors. To address the biases arising from difference between observed and simulated large-scale atmospheric projectors, and to represent anomalies of low frequency variability of teleconnections in General Circulation Models (GCMs), a Multivariate Recursive Nesting Bias Correction (MRNBC) is proposed to the regression-based statistical downscaling. The proposed method is able to use multiple variables in multiple locations to simultaneously correct temporal and spatial biases in cross dependent multi-projectors. To reduce another source of uncertainty arising from complexity and nonlinearity in quantitative empirical relationships in the statistical downscaling, the results demonstrate the superiority of a Bayesian machine-learning algorithm. The predictive power of the statistical downscaling is therefore improved through addressing the aforementioned sources of uncertainty. This results in improvement of the projection of the global warming impacts on the probabilistic behavior of hydro-climate variables using future multi-model ensemble GCMs under forcing climate change scenarios. The results of two Design-of-Experiments also reveal that the proposed comprehensive statistical downscaling is credible and adjustable to the changes under non-stationary conditions arising from climate change. Under the impact of climate change arising from anthropogenic global warming, it is demonstrated that the nature and the risk of extreme climate phenomena are changed over time. It is also well known that the extreme climate processes are multi-dimensional by their very nature characterized by multi-dimensions that are highly dependent. Accordingly, to strength the reliability of infrastructure designs and the management of water systems in the changing climate, it is of crucial importance to update the risk concept to a new adaptive multi-dimensional time-varying one to integrate anomalies of dynamic anthropogenically forced environments. The main contribution of this research is to develop a new generation of multivariate time-varying risk concept for an adaptive design framework in non-stationary conditions arising from climate change. This research develops a Bayesian, dynamic conditional copula model describing time-varying dependence structure between mixed continuous and discrete marginals of extreme multi-dimensional climate phenomena. The framework is able to integrate any anomalies in extreme multi-dimensional events in non-stationary conditions arising from climate change. It generates iterative samples using a Markov Chain Monte Carlo (MCMC) method from the full conditional marginals and joint distribution in a fully likelihood-based Bayesian inference. The framework also introduces a fully Bayesian, time-varying Joint Return Period (JRP) concept to quantify the extent of changes in the nature and the risk of extreme multi-dimensional events over time under the impact of climate change. The proposed generalized time-dependent risk framework can be applied to all stochastic multi-dimensional climate systems that are under the influence of changing environments.
Download or read book Global Change and Extreme Hydrology written by National Research Council and published by National Academies Press. This book was released on 2011-11-17 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate theory dictates that core elements of the climate system, including precipitation, evapotranspiration, and reservoirs of atmospheric and soil moisture, should change as the climate warms, both in their means and extremes. A major challenge that faces the climate and hydrologic science communities is understanding the nature of these ongoing changes in climate and hydrology and the apparent anomalies that exist in reconciling their extreme manifestations. The National Research Council (NRC) Committee on Hydrologic Science (COHS) held a workshop on January 5-6, 2010, that examined how climate warming translates into hydrologic extremes like floods and droughts. The workshop brought together three groups of experts. The first two groups consisted of atmospheric scientists and hydrologists focused on the scientific underpinnings and empirical evidence linking climate variability to hydrologic extremes. The third group consisted of water managers and decision-makers charged with the design and operation of water systems that in the future must be made resilient in light of a changing climate and an environment of hydrologic extremes. Global Change and Extreme Hydrology summarizes the proceedings of this workshop. This report presents an overview of the current state of the science in terms of climate change and extreme hydrologic events. It examines the "conventional wisdom" that climate change will "accelerate" the hydrologic cycle, fuel more evaporation, and generate more precipitation, based on an increased capacity of a warmer atmosphere to hold more water vapor. The report also includes descriptions of the changes in frequency and severity of extremes, the ability (or inability) to model these changes, and the problem of communicating the best science to water resources practitioners in useful forums.
Download or read book Beyond Downscaling written by Kara N. DiFrancesco, Patrick Ray and published by World Bank Publications. This book was released on 2014 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change adds uncertainty to already complex global water challenges. Because climate change affects poorer countries and vulnerable populations the most, the World Bank strives to mainstream climate change considerations into its operations to inform investment and water resources management decisions. Although no standard method has been adopted yet by the Bank, common practice used downscaled projected precipitation and temperature from Global Climate Models (GCMs), as input to hydrologic models. While this has been useful in some applications, they often give too wide a dispersion of readings to provide useful guidance for site-specific water resources management and infrastructure planning and design. Rather than design for an uncertain situation selected a priori, the so-called “bottom-up” approaches explore the sensitivity of a chosen project to the effects of uncertainties caused by climate change. This book summarizes alternatives explored by a group of organizations (such as the U.S. Corps of Engineers, Conservation International, the University of Massachusetts and the Bank) all belonging to the Alliance for Global Water Adaptation (AGWA), to provide practitioners with the tools to adapt to the realities of climate change by following a decision-making process that incorporates bottom-up thinking.
Download or read book Review of USGCRP Plan for a New Science Initiative on the Global Water Cycle written by National Research Council and published by National Academies Press. This book was released on 2002-05-09 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 2001, the U.S. Global Change Research Program produced the report A Plan for a New Science Initiative on the Global Water Cycle. This report was designed to represent a research strategy and scientific plan for investigating the global water cycle, and its interactions with climate and for developing an enhanced understanding of the fundamental processes that govern the availability and biogeochemistry of water resources. The USGCRP managers are currently considering how to move forward with implementation of this ambitious, broad, and potentially very fruitful plan on an interagency basis, and it requested that the National Research Council (NRC) advise them in this regard. This report, Review of USGCRP Plan for a New Science Initiative on the Global Water Cycle, provides comments on the water cycle science plan as related to its recommended scientific initiatives and goals, and it provides comments on the usefulness of the water cycle science plan to the USGCRP agencies in developing a coordinated global water cycle implementation plan.
Download or read book Climate Change Sensitive Water Resources Management written by Ramesh S.V. Teegavarapu and published by CRC Press. This book was released on 2020-12-17 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides an overview of climate change-sensitive water resources management with consideration of adaptation approaches, the assessment of climate change impacts, current contemporary management techniques, and ecological responses. Comprehensive assessments and studies from eight countries using innovative approaches that aid water management under evolving climates are documented. Topics ranging from hydrologic design to management and policy responses to climate change are discussed, which demonstrate updated theories that highlight methods, tools, and experiences on the topic of water resources under climate change. The generic approaches discussed, and their applications to different climate change-related problems, make this book appealing to a global readership. The practical and applied methodologies presented in the book and through insightful case studies discussed will provide readers worldwide with ready-to-use information to manage water resources sustainably under evolving climate. This book is ideally suited for water resource managers, scientists, professionals from water management agencies, graduate students, and national laboratory agencies responsible for water and environmental management.
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 An Atlas of the Global Water Cycle written by Wee Ho Lim and published by ANU E Press. This book was released on 2009-07-01 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: What do climate models predict for the rainfall where you live? What about evaporation or runoff? Should your local community consider constructing new dams or do the existing water storages appear adequate? What about the availability of water for irrigation farming? Do the predictions differ between different climate models or do all the models basically predict the same changes in water availability where you live? These are all simple questions but it is surprisingly hard for an individual, whether they be a farmer, water resources engineer, teacher or interested citizen, to answer them. As researchers active in the field we could not answer the questions either. In fact, we had never seen a compilation of the rainfall, evaporation and runoff predictions made by all the different climate models. The Atlas contains maps and tables that document model predictions contributed by international climate modelling groups to the 2007 4th Assessment Report of the Intergovernmental Panel on Climate Change. The predictions are made available here via the wonders of the internet and ongoing cooperation by the international climate modelling community who routinely archive their results. The maps and tables in the Atlas document rainfall, evaporation and runoff estimates for the 20th century along with predictions of the same quantities at the end of the 21st century. Whatever your interest, we hope you find the Atlas as helpful as we do.
Download or read book Decision support Experiments and Evaluations Using Seasonal to interannual Forecasts and Observational Data written by Nancy Kay Beller-Simms and published by . This book was released on 2008 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atmospheric Rivers written by F. Martin Ralph and published by Springer Nature. This book was released on 2020-07-10 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the standard reference based on roughly 20 years of research on atmospheric rivers, emphasizing progress made on key research and applications questions and remaining knowledge gaps. The book presents the history of atmospheric-rivers research, the current state of scientific knowledge, tools, and policy-relevant (science-informed) problems that lend themselves to real-world application of the research—and how the topic fits into larger national and global contexts. This book is written by a global team of authors who have conducted and published the majority of critical research on atmospheric rivers over the past years. The book is intended to benefit practitioners in the fields of meteorology, hydrology and related disciplines, including students as well as senior researchers.
Download or read book Emerging Global Water and Energy Initiatives An Integrated Perspective written by National Research Council and published by National Academies Press. This book was released on 1999-08-20 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Global Energy and Water Cycle Experiment (GEWEX) Panel of the National Research Council (NRC) was tasked by the U.S. Global Change Research Program (USGCRP) to provide a rapid and succinct assessment to relevant agencies on the general merit of the GEWEX America Prediction Project (GAPP), as well as the Coordinated Enhanced Observing Period (CEOP). In addition, the panel was asked to provide guidance to the agencies on the relationships between the agencies' newly proposed hydrologic research activities, GAPP, and CEOP. Providing this guidance is critical, in part, because the federal agencies tend to have somewhat differing priorities across the wide span of GEWEX activities.
Download or read book Regional Hydrological Response to Climate Change written by J. A. A. Jones and published by Springer Science & Business Media. This book was released on 1996 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1. Predicting the Hydrological Effects of Climate Change.- Section I Sensitivity of the Global Hydrosphere Section Summary.- 2. An Introduction to Global Water Dynamics.- 3. Modelling the Biospheric Aspects of the Hydrological Cycle: Upscaling Processes and Downscaling Weather Data.- 4. Trends in Historical Steamflow Records.- Section II Regional Implications of Global Warming Section Summary.- 5. Hydrology of Northern North America under Global Warming.- 6. Current Evidence on the Likely Impact of Global Warming on Hydrological Regimes in Europe.- 7. The Impact of Climatic Warming on Hydrological Regimes in China: An Overview.- Section III Precipitation Change and Variability Section Summary.- 8. The Influence of Topography, Season and Circulation on Spatial Patterns of Daily Precipitation.- 9. Use of Artificial Neural Networks in Precipitation Forecasting.- 10. Generation of Sequences of Air Temperature and Precipitation for Estimation of the Hydrological Cycle in Changing Climatic Conditions in Poland.- 11. Some Aspects of Climatic Fluctuation at Four Stations on the Tibetan Plateau during the Last 40 Years.- 12. The Influences of the North Atlantic Oscillation, the El Niño/Southern Oscillation and the Quasi-Biennial Oscillation on Winter Precipitation in Ireland.- Section IV Impacts on Snow, Ice and Meltwaters Section Summary.- 13. Runoff Formation and Discharge Modelling of a Glacierized Basin in the Tianshan Mountains.- 14. Impact of Future Climate Change on Glacier Runoff and the Possibilities for Artificially Increasing Melt Water Runoff in the Aral Sea Basin.- 15. Glaciers and Snowcover in Central Asia as Indicators of Climate Change in the Earth-Ocean-Atmosphere System.- 16. Global Warming and the Trend toward Dryness in the Frigid High Mountains and Plateau of Western China.- Section V The Water Balance and Changing Regional Resources Section Summary.- 17. A Method to Assess the Effects of Climatic Warming on the Water Balance of Mountainous Regions.- 18. Sensitivity Analyses for the Impact of Global Warming on Water Resources in Wales.- 19. Potential Hydrological Responses to Climate Change in Australia.- 20. Dynamics of Stage Fluctuation in Yangzhouyongcuo Lake, Tibetan Plateau.- 21. Derivation of Surface Temperature, Albedo, and Radiative Fluxes over the Tibetan Plateau Based on Satellite Measurement.- 22. Climatic Warming and its Impact on the Water Resources of the Yalong River, China.- 23. The Probable Impact of Global Change on the Water Resources of Patagonia, Argentina.- 24. Long Term Trends in the Water Balance of Central Japan.- Conclusions.- 25. The Impact of Global Warming on Regional Hydrology and Future Research Priorities.
