A Stochastic Model of Space-Time Variability of Mesoscale Rainfall
A Stochastic Model of Space-Time Variability of Mesoscale Rainfall

Author: Prasun K. Kundu

Publisher: BiblioGov

Published: 2013-08

Total Pages: 22

ISBN-13: 9781289285388

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A characteristic feature of rainfall statistics is that they depend on the space and time scales over which rain data are averaged. A previously developed spectral model of rain statistics that is designed to capture this property, predicts power law scaling behavior for the second moment statistics of area-averaged rain rate on the averaging length scale L as L right arrow 0. In the present work a more efficient method of estimating the model parameters is presented, and used to fit the model to the statistics of area-averaged rain rate derived from gridded radar precipitation data from TOGA COARE. Statistical properties of the data and the model predictions are compared over a wide range of averaging scales. An extension of the spectral model scaling relations to describe the dependence of the average fraction of grid boxes within an area containing nonzero rain (the "rainy area fraction") on the grid scale L is also explored.

Space and Time Scale Variability and Interdependencies in Hydrological Processes
Space and Time Scale Variability and Interdependencies in Hydrological Processes

Author: R. A. Feddes

Publisher: Cambridge University Press

Published: 1995-08-24

Total Pages: 198

ISBN-13: 0521495083

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This book presents the integrated contributions of hydrologists, meteorologists and ecologists to the first IHP/IAHS George Kovacs Colloquium in connection with the study of global hydrology and climate change. The atmospherical, hydrological and terrestrial components of the Earth's systems operate on different time and space scales. Resolving these scaling incongruities, as well as understanding and modelling the complex interaction of land surface processes at the different scales, represent a major challenge for hydrologists, ecologists and meteorological scientists alike. This book deals with time and space scale variations with reference to several topics including: soil water balance; ecosystems and interaction of flow systems; and macroscale hydrological modelling. This book will be of great use to researchers, engineers and forecasters with an interest in space and time scale variability.

A Stochastic Space-time Rainfall Model for Engineering Risk Assessment
A Stochastic Space-time Rainfall Model for Engineering Risk Assessment

Author: Michael Leonard

Publisher:

Published: 2010

Total Pages: 253

ISBN-13:

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The temporal and spatial variability of Australia's climate affects the quantity and quality of its water resources, the productivity of its agricultural systems, and the health of its ecosystems. This variability should be taken into account when assessing the risks associated with flooding. Continuous simulation rainfall models are one means for doing this, whereby sequences of storms are generated for an arbitrarily long time period and over some region of interest. The simulated rainfall should reproduce observed statistics in time and space so that it can be used as a suitable input for hydrologic models at the catchment scale, with particular emphasis on extreme events. There are a variety of approaches to modelling rainfall, including a broad range of single-site and multi-site rainfall models. By way of contrast there are few models that aim to simulate rainfall across all points within a region at daily or sub-daily increments. This thesis focuses on models calibrated solely to rain gauges, and a specific type known as Neyman-Scott Rectangular Pulse (NSRP) models. Existing NSRP models have a mature history of modelling developments including calibration methodology and an ability to reproduce key statistics across a range of timescales. Nonetheless, these models also have several limitations (and other space-time models not withstanding) that are addressed in this thesis. These developments include improvements to the conceptual representation of rainfall and improvements to calibration and simulation techniques. Specifically these improvements include (i) the development of an efficient simulation technique, (ii) assessing the impact of monthly parameter changes on rainfall statistics, (iii) the use of simulated statistics within calibration to overcome reliance on derived model properties (iv) incorporating a storm extent parameter to better match spatial correlations, (v) incorporating long term climatic variability and developing a methodology to assess climatic and seasonal variability in simulated extremes (vi) incorporating inhomogeneity of rainfall occurrence across a region. Numerous case studies are used at various locations about Australia to illustrate these improvements and highlight the applicability of the model under varied climatic conditions.

Radio Wave Propagation and Channel Modeling for Earth-Space Systems
Radio Wave Propagation and Channel Modeling for Earth-Space Systems

Author: Athanasios G. Kanatas

Publisher: CRC Press

Published: 2017-12-19

Total Pages: 368

ISBN-13: 1482249715

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The accurate design of earth–space systems requires a comprehensive understanding of the various propagation media and phenomena that differ depending on frequencies and types of applications. The choice of the relevant channel models is crucial in the design process and constitutes a key step in performance evaluation and testing of earth–space systems. The subject of this book is built around the two characteristic cases of satellite systems: fixed satellites and mobile satellite systems. Radio Wave Propagation and Channel Modeling for Earth–Space Systems discusses the state of the art in channel modeling and characterization of next-generation fixed multiple-antennas and mobile satellite systems, as well as propagation phenomena and fade mitigation techniques. The frequencies of interest range from 100 MHz to 100 GHz (from VHF to W band), whereas the use of optical free-space communications is envisaged. Examining recent research advances in space-time tropospheric propagation fields and optical satellite communication channel models, the book covers land mobile multiple antennas satellite- issues and relative propagation campaigns and stratospheric channel models for various applications and frequencies. It also presents research and well-accepted satellite community results for land mobile satellite and tropospheric attenuation time-series single link and field synthesizers. The book examines aeronautical communications channel characteristics and modeling, relative radio wave propagation campaigns, and stratospheric channel model for various applications and frequencies. Propagation effects on satellite navigation systems and the corresponding models are also covered.

Stochastic Modelling of Space-Time Rainfall
Stochastic Modelling of Space-Time Rainfall

Author: Marie-Laure Segond

Publisher: LAP Lambert Academic Publishing

Published: 2010-10

Total Pages: 232

ISBN-13: 9783843355469

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In the context of flood management, this thesis investigates the relationship between spatial rainfall and runoff production, for a range of scales and catchment types. A methodology for the spatial-temporal rainfall simulation of hourly rainfall is developed and the sensitivity of simulated flood runoff to the representation of observed and simulated spatial rainfall is evaluated. The study is based on 15 years of radar data, 21 raingauges and 12 flow stations from the 1400 km2 Lee catchment, UK. Results show a complex picture. The dominant effect is the spatial variability of the rainfall. No clear pattern emerges as a function of catchment scale, or response time, except that the impact of spatial variability is damped at the whole catchment scale. The sensitivity to spatial rainfall is enhanced on urbanised catchments. In conclusion, the thesis provides specific guidance concerning the importance of spatial rainfall for flood estimation.

Rainfall
Rainfall

Author: Firat Y. Testik

Publisher: John Wiley & Sons

Published: 2013-05-02

Total Pages: 500

ISBN-13: 1118671546

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Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 191. Rainfall: State of the Science offers the most up-to-date knowledge on the fundamental and practical aspects of rainfall. Each chapter, self-contained and written by prominent scientists in their respective fields, provides three forms of information: fundamental principles, detailed overview of current knowledge and description of existing methods, and emerging techniques and future research directions. The book discusses Rainfall microphysics: raindrop morphodynamics, interactions, size distribution, and evolution Rainfall measurement and estimation: ground-based direct measurement (disdrometer and rain gauge), weather radar rainfall estimation, polarimetric radar rainfall estimation, and satellite rainfall estimation Statistical analyses: intensity-duration-frequency curves, frequency analysis of extreme events, spatial analyses, simulation and disaggregation, ensemble approach for radar rainfall uncertainty, and uncertainty analysis of satellite rainfall products The book is tailored to be an indispensable reference for researchers, practitioners, and graduate students who study any aspect of rainfall or utilize rainfall information in various science and engineering disciplines.

Treatise on Water Science
Treatise on Water Science

Author:

Publisher: Newnes

Published: 2010-09-01

Total Pages: 2131

ISBN-13: 0444531998

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Water quality and management are of great significance globally, as the demand for clean, potable water far exceeds the availability. Water science research brings together the natural and applied sciences, engineering, chemistry, law and policy, and economics, and the Treatise on Water Science seeks to unite these areas through contributions from a global team of author-experts. The 4-volume set examines topics in depth, with an emphasis on innovative research and technologies for those working in applied areas. Published in partnership with and endorsed by the International Water Association (IWA), demonstrating the authority of the content Editor-in-Chief Peter Wilderer, a Stockholm Water Prize recipient, has assembled a world-class team of volume editors and contributing authors Topics related to water resource management, water quality and supply, and handling of wastewater are treated in depth

Statistical Downscaling and Bias Correction for Climate Research
Statistical Downscaling and Bias Correction for Climate Research

Author: Douglas Maraun

Publisher: Cambridge University Press

Published: 2018-01-18

Total Pages: 365

ISBN-13: 110834030X

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Statistical downscaling and bias correction are becoming standard tools in climate impact studies. This book provides a comprehensive reference to widely-used approaches, and additionally covers the relevant user context and technical background, as well as a synthesis and guidelines for practitioners. It presents the main approaches including statistical downscaling, bias correction and weather generators, along with their underlying assumptions, skill and limitations. Relevant background information on user needs and observational and climate model uncertainties is complemented by concise introductions to the most important concepts in statistical and dynamical modelling. A substantial part is dedicated to the evaluation of regional climate projections and their value in different user contexts. Detailed guidelines for the application of downscaling and the use of downscaled information in practice complete the volume. Its modular approach makes the book accessible for developers and practitioners, graduate students and experienced researchers, as well as impact modellers and decision makers.