Download or read book Coupled Dynamics in Soil Understanding the Transport Mechanism of Liquid Water Water Vapor Dry Air and Heat by Field Experiment and Numerical Simulation written by Yijian Zeng and published by . This book was released on 2012 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coupled Dynamics in Soil written by Yijian Zeng and published by Springer Science & Business Media. This book was released on 2012-12-14 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: In arid and semi-arid areas, the main contributions to land surface processes are precipitation, surface evaporation and surface energy balancing. In the close-to-surface layer and root-zone layer, vapor flux is the dominant flux controlling these processes - process which, in turn, influence the local climate pattern and the local ecosystem. The work reported in this thesis attempts to understand how the soil airflow affects the vapor transport during evaporation processes, by using a two-phase heat and mass transfer model. The necessity of including the airflow mechanism in land surface process studies is discussed and highlighted.
Download or read book Coupled Heat and Water Transport in Bare Soils in Semi arid and Arid Regions written by T. Berends and published by . This book was released on 2012 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: For more than 50 years coupled heat and water transport is an interesting topic in the field of vadose zone hydrology. One basis is the theory by Philip & de Vries (1957) which couples the mass balance for water, the Richards equation, with a heat conservation equation based on Fickian diffusion process. In this thesis the contribution of water vapour flow to the total water movement on a daily time scale is analysed. At first the literature is reviewed, starting from the theory of Philip and de Vries and the many papers which have continued on this theory. Next to the theory also the literature on experiments associated to coupled transport is reviewed, distinguishing field and laboratory experiments. Data were collected during field work in Trabadillo, Spain under semi-arid weather conditions. Soil water pressure, soil water content and soil temperature were measured for 149 days on an hourly interval during the dry period. The soil hydraulic and soil thermal parameters are calibrated on this data in Hydrus-1D by using an inverse parameter estimated method. In the calibrated Hydrus model Monte Carlo simulations are performed to include the uncertainty in the parameters. Instantaneous fluxes of liquid water, isothermal water vapour and thermal water vapour flow are examined at multiple moments in time. Selecting fluxes for inclusion on an daily time basis in the SWAP model, the Hydrus 1-D isothermal water vapour flow is zero during night and day and is therefore not included in the SWAP model. A significant daily pattern is identified for the thermal water vapour flux and this flux is implemented in SWAP in addition to the standard isothermal liquid water flux. The cumulative net flux is computed for four different models, a Hydrus and SWAP model with only liquid water transport and a Hydrus and SWAP model with both coupled heat and water transport. Intercomparison between the four model versions showed that the contribution of water vapour flow is insignificant compared to the total transport of water. As a sensitivity analysis in addition to the soil hydraulic parameters from the field situation, simulations are also performed for a European set of soils from the HYPRESS project Wosten et al. (1999). The Hydrus model did not converge to a satisfactory numerical solution with a maximum spatial discretisation of 1 cm, which is advised by Simunek et al. (2008). In SWAP the contribution of water vapour movement to the total water transport is insignificant on a daily time scale for all the soil types. Finally a laboratory experiment design is proposed with the focus on coupled heat and water transport. The plan for the laboratory experiment will be based on the experience from the fieldwork and the literature study. Important components for this plan are the type of measurement devices, the spatial set-up of those devices and the boundary conditions. A model study is executed to look for the optimal measurement set-up for a laboratory experiment to liquid water and water vapour transport. Inverse modelling is used to determine the soil hydraulic and soil heat parameters from a selection of data and direct modeling is performed with the determined parameters to compare the accuracy of these parameters and so the data selection. The optimal laboratory design according to the model study includes measurements of soil temperature, soil water content and soil water pressure at depths of 5, 25 and 50 cm beneath the soil surface.
Download or read book Encyclopedia of Agrophysics written by Jan Gliński and published by Springer Science & Business Media. This book was released on 2011-06-07 with total page 1075 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Encyclopedia of Agrophysics will provide up-to-date information on the physical properties and processes affecting the quality of the environment and plant production. It will be a "first-up" volume which will nicely complement the recently published Encyclopedia of Soil Science, (November 2007) which was published in the same series. In a single authoritative volume a collection of about 250 informative articles and ca 400 glossary terms covering all aspects of agrophysics will be presented. The authors will be renowned specialists in various aspects in agrophysics from a wide variety of countries. Agrophysics is important both for research and practical use not only in agriculture, but also in areas like environmental science, land reclamation, food processing etc. Agrophysics is a relatively new interdisciplinary field closely related to Agrochemistry, Agrobiology, Agroclimatology and Agroecology. Nowadays it has been fully accepted as an agricultural and environmental discipline. As such this Encyclopedia volume will be an indispensable working tool for scientists and practitioners from different disciplines, like agriculture, soil science, geosciences, environmental science, geography, and engineering.
Download or read book Computer Simulation of Soil water Dynamics written by Daniel Hillel and published by . This book was released on 1977 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamental principles of modeling and simulation; Isothermal evaporation of soil water under fluctuating evaporativity, including the role of hysteresis; Non-isothermal evaporation of soil water, including the effect of surface reflectivity; Water dynamics and storage in fallow soils as affected by soil texture and profile layering; Hydrology of a sloping field, including surface runoff and groundwater flow; Moisture extraction by root systems, and the concurrent movement of water and salt in the soil profiles.
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:
Download or read book Coupled Dynamics in Soil written by Springer and published by . This book was released on 2012-12-14 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coupled Movement of Liquid Water Water Vapor and Heat in Deep Vadose Zones written by Raneem Madi and published by . This book was released on 2018* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Arid/Semi-arid regions; groundwater recharge; deep vadose zone; soil hydraulic properties; parameterizations; liquid/vapor water flow; atmospheric signal; long term simulations
Download or read book Soil water Interactions written by Shingo Iwata and published by . This book was released on 1988 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emphasizing pioneering achievements, this work offers a clear and systematic description of various soil-water phenomena and their applications to soil problems such as water retention and the flux of water in soils and clays. This second edition contains material on the physical properties of adsorbed water, the application of fractal theory to solute and water flows in field soils, fingering research, and more.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1987 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biological Soil Crusts Structure Function and Management written by Jayne Belnap and published by Springer Science & Business Media. This book was released on 2013-12-01 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: In arid lands, where vegetation is sparse or absent, the open ground is not bare but generally covered by a community of small, highly specialized organisms. Cyanobacteria, algae, microfungi, lichens, and bryophytes aggregate soil particles to form a coherent skin - the biological soil crust. It stabilizes and protects the soil surface from erosion by wind and water, influences water runoff and infiltration, and contributes nitrogen and carbon to desert soils. Soil surface disturbance, such as heavy livestock grazing, human trampling or off-road vehicles, breaks up the fragile soil crust, thus compromising its stability, structure, and productivity. This book is the first synthesis of the biology of soil crusts and their importance as an ecosystem component. Composition and functioning of different soil-crust types are discussed, and case studies are used to show the impact of crusts on landscape hydrology, soil stability, nutrient cycles, and land management.
Download or read book Soil Physics with Python written by Marco Bittelli and published by . This book was released on 2015 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: This innovative study presents concepts and problems in soil physics, and provides solutions using original computer programs. It provides a close examination of physical environments of soil, including an analysis of the movement of heat, water and gases. The authors employ the programminglanguage Python, which is now widely used for numerical problem solving in the sciences. In contrast to the majority of the literature on soil physics, this text focuses on solving, not deriving, differential equations for transport. Using numerical procedures to solve differential equations allowsthe solution of quite difficult problems with fairly simple mathematical tools. Numerical methods convert differential into algebraic equations, which can be solved using conventional methods of linear algebra. Each chapter introduces a soil physics concept, and proceeds to develop computer programsto solve the equations and illustrate the points made in the discussion.Problems at the end of each chapter help the reader practise using the concepts introduced. The text is suitable for advanced undergraduates, graduates and researchers of soil physics. It employs an open source philosophy where computer code is presented, explained and discussed, and provides thereader with a full understanding of the solutions. Once mastered, the code can be adapted and expanded for the user's own models, fostering further developments. The Python tools provide a simple syntax, Object Oriented Programming techniques, powerful mathematical and numerical tools, and a userfriendly environment.
Download or read book Understanding Soil Water Interaction Mechanisms Via Molecular Simulations written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Soil-water interaction is important to understand various soil behaviors. However, the theoretical understanding of soil-water interaction mechanisms is still incomplete especially in the adsorptive regime of soil water retention curves. Molecular simulation techniques were introduced herein to fill historical knowledge gaps in classical soil mechanics, to provide a novel angle to characterize soil behaviors and to promote the theoretical understanding of soil-water interaction. First, a general framework was developed to determine the contact angles of soil minerals. This procedure was employed to simulate the contact angles of ꭤ-quartz, orthoclase and muscovite. The simulated contact angles showed good agreement with the reported experimental or numerical results and thus substantiated the feasibility and accuracy of the proposed method. Second, molecular dynamics was employed to investigate the freezing and melting of water confined in nano-size pores. A general framework based on molecular dynamics simulations was developed to investigate the phase transition behavior of water confined in nano-size pores. It is found that the Young-Laplace equation may not apply in the low temperature range. An unfreezable threshold was identified in the phase composition curves and found to correspond to a pore diameter of 2.3±0.1 nm. Third, molecular dynamics was utilized to understand stress states of porous materials. A general framework was developed to extract effective stress from molecular simulations. Numerical simulations showed that the intergranular stress is different from the effective stress. Then, another simulation procedure was established to characterize nanoscale liquid bridges. Comparisons between macroscopic solution and simulation results revealed that the interplay of adsorption and capillarity is substantial at the nanoscale. At last, a general theoretical framework based on metadynamics was proposed to determine the lowest matric potential. The matric potential was derived from partial volume free energy and can be further calculated by the adsorption free energy. The lowest matric potential was determined as -2.00 GPa. In all of these studies, molecular simulations have shown strong potentials to resolve critical issues in soil behavior involving multiple phases. It is expected that the proposed general frameworks will open a new window to characterize soil-water interaction.
Download or read book The Coupled Transport of Water and Heat in a Vertical Soil Column Under Atmospheric Excitation written by P. E. D. Milly and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evapotranspiration in the Soil Plant Atmosphere System written by Viliam Novak and published by Springer Science & Business Media. This book was released on 2012-06-25 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evapotranspiration and its components (evaporation and transpiration) as a process is one of the basic terms of Earth's water balance; its importance is accented by the fact that transpiration is the vital element of the biomass production process. The second important property of evapotranspiration is its extreme consumption of solar energy, thus controlling the temperature of the atmosphere and creating favourable conditions for life. Evapotranspiration as an energy consuming process is also the connection between the energy and mass cycles of the Earth. Evapotranspiration is a process performing in the Soil–Plant –Atmosphere System (SPAS); therefore this book is presenting and quantifying it as a catenary process, describing transport of water in the soil, including root extraction patterns and methods of its evaluation. Transport of water through the plant and from the canopy to the atmosphere is also described and quantified. A variety of evapotranspiration (and its components evaporation and transpiration) calculation methods are described, starting from empirical methods up to the most sophisticated ones based on the solution of the transport equations of water and energy in the SPAS. The most important (and widely used) calculation method - modified Penman–Monteith method is described in details, ready to be used with data in the book only. Water balance method of evapotranspiration estimation as well as sap flow method description can be found in the book as well. The book can be used by hydrologists, biologists, meteorologists and other specialists as well as by ecology students. Key themes: soil hydrology – evapotranspiration – hydropedology– plant physiology – water movement in soils – evaporation – transpiration Dr. Viliam Novák is a water resources scientist at the Institute of Hydrology of the Slovak Academy of Sciences in Bratislava (Slovakia).
Download or read book The Atmospheric Sciences written by Board on Atmospheric Sciences and Climate and published by National Academies Press. This book was released on 1998-11-05 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Technology has propelled the atmospheric sciences from a fledgling discipline to a global enterprise. Findings in this field shape a broad spectrum of decisions--what to wear outdoors, whether aircraft should fly, how to deal with the issue of climate change, and more. This book presents a comprehensive assessment of the atmospheric sciences and offers a vision for the future and a range of recommendations for federal authorities, the scientific community, and education administrators. How does atmospheric science contribute to national well-being? In the context of this question, the panel identifies imperatives in scientific observation, recommends directions for modeling and forecasting research, and examines management issues, including the growing problem of weather data availability. Five subdisciplines--physics, chemistry, dynamics and weather forecasting, upper atmosphere and near-earth space physics, climate and climate change--and their status as the science enters the twenty-first century are examined in detail, including recommendations for research. This readable book will be of interest to public-sector policy framers and private-sector decisionmakers as well as researchers, educators, and students in the atmospheric sciences.
Download or read book Aviation Weather for Pilots and Flight Operations Personnel written by United States. Federal Aviation Administration and published by . This book was released on 1975 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
