Download or read book Parameter Estimation of Coupled Water and Energy Balance Models Based on Stationarity Constraints of Soil Moisture and Temperature written by Jian Sun and published by . This book was released on 2012 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: A new method is developed for estimating the parameters of land surface water and energy balance models through enforcement of stationary constraints on soil moisture and temperature. Through conditional averaging of the water balance equation with respect to soil moisture and the energy balance equation with respect to surface temperature, a measure of stationarity is derived that approximates the errors present in predicted fluxes (e.g. evaporation, runoff, sensible heat, ground conduction) in terms of measured model inputs (e.g. precipitation, radiation, soil moisture and temperature). Minimization of the approximated error yields estimates of model parameters. The approach is distinct from traditional model calibration because the minimized error term does not depend on measurements of the predicted fluxes. This proposed method is applied to a land surface water and energy balance model similar to those used in global climate models. The approach is tested at two Ameriflux sites with continuous in-situ measurements of soil moisture, temperature, radiation, and surface turbulent fluxes (evapotranspiration and sensible heat). Fluxes estimated with the proposed method match field measurements approximately as well as those estimated by traditional calibration. Replacing the in-situ land surface temperature and soil moisture with estimates retrieved from satellite leads to minimal degradation of model performance. Sensitivity analysis at these sites demonstrates that increasing model complexity does not improve performance. With promising results from testing the approach at these field sites, the method is applied to estimate evapotranspiration over the Southern Great Plains region of North America. In this test, archived meteorological data and remotely sensed moisture and temperature are used to force the model. The spatial pattern of estimated mean annual evapotranspiration is in good agreement (RMSE of 8 Wm-2 , R 2 of 0.75) with published estimates derived from measured precipitation and streamflow. Estimated parameters are reasonably distributed and consistent with climate and vegetation patterns over the region. Because there are so few sites on earth where surface turbulent fluxes are measured, the proposed approach is more widely applicable than traditional calibration methods, and thus could be used, with satellite data, to estimate maps of land surface parameters required by global climate models.
Download or read book Directory of Geoscience Departments 2015 written by Carolyn Wilson and published by American Geosciences Inst. This book was released on 2015-02-27 with total page 2140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Directory of Geoscience Departments 50th Edition is the most comprehensive directory and source of information about geosciences departments and researchers available. It is an invaluable resource for individuals working in the geosciences or must identify or work with specialists on the issues of Earth, Environmental, and related sciences and engineering fields. The Directory of Geoscience Departments 50th Edition provides a state/country-sorted listing of nearly 2300 geoscience departments, research departments, institutes, and their faculty and staff. Information on contact information for departments and individuals is provided, as well as details on department enrollments, faculty specialties, and the date and source of faculty and staff's highest degree. New in the 50th edition: Listing of all US and Canadian geoscience theses and dissertations accepted in 2012 that have been reported to GeoRef Information Services, as well as a listing of faculty by their research specialty.
Download or read book Estimation of Land Surface Water and Energy Balance Flux Components and Closure Relation Using Conditional Sampling written by Leila Farhadi and published by . This book was released on 2012 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: Models of terrestrial water and energy balance include numerical treatment of heat and moisture diffusion in the soil-vegetation-atmosphere continuum. These two diffusion and exchange processes are linked only at a few critical points. The performance and sensitivity of models are highly dependent on the nature of these linkages that are expressed as the closure function between heat and moisture dynamics. Land response to radiative forcing and partitioning of available energy into sensible and latent heat fluxes are dependant on the functional form. Since the function affects the surface fluxes, the influence reaches through the boundary layer and affects the lower atmosphere weather. As important as these closure functions are, they remain essentially empirical and untested across diverse conditions. It is critically important to develop observation-driven estimation procedures for the terrestrial water and energy closure problem, especially at the scale of modeling and with global coverage. In this dissertation a new approach to the estimation of key unknown parameters of water and energy balance equation and their closure relationship is introduced. This approach is based on averaging of heat and moisture diffusion equations conditioned on land surface temperature and moisture states respectively. The method is derived only from statistical stationarity and conservation statements of water and energy and thus it is scale free. The aim of this dissertation is to establish the theoretical basis for the approach and perform a global test using multi-platform remote sensing measurements. The feasibility of this approach is demonstrated at point-scale using synthetic data and flux-tower field site data. The method is applied to the mesoscale region of Gourma (West Africa) using multi-platform remote sensing data. The retrievals were verified against tower-flux field site data and physiographic characteristics of the region. The approach is used to find the functional form of the Evaporative Fraction (ratio of latent heat flux to sum of latent and sensible heat fluxes) dependence on soil moisture. Evaporative Fraction is a key closure function for surface and subsurface heat and moisture dynamics. With remote sensing data the dependence of this function on governing soil and vegetation characteristics is established.
Download or read book Parameter Estimation and Uncertainty Quantification in Water Resources Modeling written by Philippe Renard and published by Frontiers Media SA. This book was released on 2020-04-22 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical models of flow and transport processes are heavily employed in the fields of surface, soil, and groundwater hydrology. They are used to interpret field observations, analyze complex and coupled processes, or to support decision making related to large societal issues such as the water-energy nexus or sustainable water management and food production. Parameter estimation and uncertainty quantification are two key features of modern science-based predictions. When applied to water resources, these tasks must cope with many degrees of freedom and large datasets. Both are challenging and require novel theoretical and computational approaches to handle complex models with large number of unknown parameters.
Download or read book Simultaneous Inverse Estimation of Coupled Water Heat and Solute Transport Parameters with Model Validation and Predictive Analysis written by Michael James Friedel and published by . This book was released on 2002 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parameter Estimation of One dimensional Soil Moisture Dynamics Model written by Ajit Kumar and published by . This book was released on 2002 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Field scale Water Flow and Solute Transport written by Jos C. van Dam and published by . This book was released on 2000 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecohydrology written by Peter S. Eagleson and published by Cambridge University Press. This book was released on 2005-02-17 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume investigates how the physical characteristics and productivity of forest communities are related to the climates and soils in which they are found. It will provide fascinating reading for graduate-level students and research scientists working in ecohydrology, hydroclimatology, forest ecology, and surface water hydrology.
Download or read book An Agenda of Science for Environment and Development Into the 21st Century written by James Dooge and published by Cambridge University Press. This book was released on 1992-05-28 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: The world scientific community's definitive statement on strategies needed to safeguard the environment and promote development.
Download or read book Penman s Method for Estimating Soil Moisture from Evaporation written by R. L. Closs and published by . This book was released on 1956 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Water Dynamics in the Soil plant atmospheric Continuum in a Water controlled Ecosystem written by Xingyuan Chen and published by . This book was released on 2009 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coupling Large scale Hydrological and Atmospheric Models written by G. A. Schultz and published by . This book was released on 1995 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parameter Estimation Technique for a Water Balance Model and Application to Measured Data written by Vania Toninelli and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physically Based Parameter Estimation Methods for Hydrological Models written by Evison Kapangaziwiri and published by LAP Lambert Academic Publishing. This book was released on 2011-06 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reliable quantification of available water resources is an important prerequisite for sustainable management and development. However, the data required for adequate resource estimation are usually not available due to inadequate and shrinking measurement networks. Hydrologic models are the standard tool used to generate continuous estimates of stream flow and regionalisation has been the traditional approach to model application in poorly gauged basins. The classical approach to regionalization is to calibrate against naturalized observed data, identify hydrologically similar basins, and then transfer calibrated parameter sets to the ungauged basins. One of the problems related to this approach is the relatively few basins for calibration in southern Africa (due to data quality and availability problems), resulting in huge uncertainties in the prediction process. This study proposes an a priori process to directly estimate parameters of the Pitman monthly rainfall runoff model based on physical basin characteristics. The approach is tested on selected basins in southern African.
Download or read book A Nodal Domain Integration Model of Two dimensional Heat and Soil water Flow Coupled by Soil water Phase Change written by Theodore V. Hromadka and published by . This book was released on 1987 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Soil Moisture Model to Improve Mineral Abundance Estimates from Hyperspectral Data written by Michael Lawrence Whiting and published by . This book was released on 2004 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Coupled Transport of Water and Heat in a Vertical Soil Column Under Atmospheric Excitation written by Paul Christopher Damian Milly and published by . This book was released on 1980 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
