Download or read book Estimation of Evapotranspiration Using Continuous Soil Moisture Measurement written by Mandana Seyed Rahgozar and published by . This book was released on 2006 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new methodology is proposed for estimation of evapotranspiration (ET) flux at small spatial and temporal scales. The method involves simultaneous measurement of soil moisture (SM) profiles and water table heads along transects flow paths. The method has been applied in a shallow water table field site in West-Central Florida for data collected from January 2002 through June 2004. Capacitance shift type moisture sensors were used for this research, placed at variable depth intervals starting at approximately 4 in. (10 cm) below land surface and extending well below the seasonal low water table depth of 59 in. (1.5 m). Vegetation included grassland and wetland forested flatwoods. The approach includes the ability to resolve multiple ET components including shallow and deep vadose zone, surface interception capture and depression storage ET. Other components of the water budget including infiltration, total and saturation rainfall excess runoff, net runoff, changes in storage and lateral groundwater flows are also derived from the approach. One shortcoming of the method is the reliance on open pan or other potential ET estimation techniques when the water table is at or near land surface. Results are compared with values derived for the two vegetative covers from micrometeorological and Bowen ratio methods. Advantages of the SM method include resolving component ET.
Download or read book Estimating Soil Moisture Conditions and Time for Irrigation with the Evapotranspiration Method written by Cornelius H. M. Van Bavel and published by . This book was released on 1957 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Measurement of Soil Moisture and the Estimation of Evapotranspiration at Claverly East Salop written by Sabah Abbas Abdulla and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The estimation of soil moisture content and actual evapotranspiration using thermal infrared remote sensing written by R. J. Gurney and published by . This book was released on 1978 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimating Soil Moisture Conditions and Time for Irrigation With the Evapotranspiration Method Classic Reprint written by Cornelius H. M. van Bavel and published by Forgotten Books. This book was released on 2018-08-30 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Estimating Soil Moisture Conditions and Time for Irrigation With the Evapotranspiration Method Item.(l) above is then represented by the field capacity moisture content on avolume basiso It is best determined by a sampling of the profile after a heavy rain or irrigation for moisture content by weight and for bulk density. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
Download or read book Remote Determination of Soil Moisture and Evapotranspiration from Thermal Infrared Measurements written by Toby N. Carlson and published by . This book was released on 1994 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Methods of Soil Moisture Estimation for Water Balance Purposes written by Miroslav Kutílek and published by . This book was released on 1971 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimation of Evapotranspiration in the Rainbow Springs and Silver Springs Basins in North Central Florida written by Leel Knowles and published by . This book was released on 1996 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evapotranspiration written by Ayse Irmak and published by BoD – Books on Demand. This book was released on 2012-01-18 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edition of Evapotranspiration - Remote Sensing and Modeling contains 23 chapters related to the modeling and simulation of evapotranspiration (ET) and remote sensing-based energy balance determination of ET. These areas are at the forefront of technologies that quantify the highly spatial ET from the Earth's surface. The topics describe mechanics of ET simulation from partially vegetated surfaces and stomatal conductance behavior of natural and agricultural ecosystems. Estimation methods that use weather based methods, soil water balance, the Complementary Relationship, the Hargreaves and other temperature-radiation based methods, and Fuzzy-Probabilistic calculations are described. A critical review describes methods used in hydrological models. Applications describe ET patterns in alpine catchments, under water shortage, for irrigated systems, under climate change, and for grasslands and pastures. Remote sensing based approaches include Landsat and MODIS satellite-based energy balance, and the common process models SEBAL, METRIC and S-SEBS. Recommended guidelines for applying operational satellite-based energy balance models and for overcoming common challenges are made.
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 An Empirical Model to Estimate Transpiration and Evaporation from Soil Moisture written by Hala Charif Fayad and published by . This book was released on 1994 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Estimation of evapotranspiration (ET) is extremely important in water resources management. Many attempts have been made by several investigators to separate ET into evaporation (E) and transpiration (T) . The majority of work was done on determining ET and E. Then, T is determined by subtracting E from ET. Four experiments were conducted at the glass house of the American University of Beirut. The main purpose of these experiments was to establish a relation between evaporation rate and volumetric water content (0v) . Three soils of different textures from different sites of Lebanon were used: A sandy soil, a sandy clay loam soil, and a clayey soil. The first experiment consisted of placing eight microlysimeters containing 12 cm deep soil on a turntable inside the glass house. Evaporation was measured daily for actual and potential conditions. The relation between 0v and the ratio of actual to potential E proved to be linear and passing through the origin. The slope of the function was 0.019 for the first drying cycle and 0.035 for the second with an R2 of 0.82 for the first and 0.92 for the second. The second experiment was similar to the first one in principle. Three liter pots were used instead of the microlysimeters. These pots were placed inside the glass house on a fixed bench. The resulting function was similar to the one obtained in the first experiment; however, the Values of the slopes ranged from 0.17 to 0.27 with R2 ranging from 0.83 to 0.96, for all replicates and drying cycles. Moreover, the slope of the functions decreased with an increase in the number of drying cycles. Experiment three was designed to measure ET from pots planted with sunflower. The relationship between relative ET (ratio of actual to potential) and 6v proved to be linear and passing through the origin. The slope was 0.026 and R2 was 0.94. Experiment four consisted of placing planted pots covered with clear and black mulch on a fixed bench inside the glass house. Its aim was to measure transpiration. Using the results obtained from experiments 2, 3, and 4, an attempt was made to separate ET into its components E and T. The objective was not achieved with high confidence due to the short growing period. Results from this experiment agreed with the hypothesis that evaporation constitutes the major component of ET during early crop development.
Download or read book Soil Moisture Measurement and Assessment written by Australian Water Resources Council and published by . This book was released on 1974 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimating Soil Moisture Conditions and Time for Irrigation with the Evapotranspiration Method written by Cornelius H. M. Van Bavel and published by . This book was released on 1956 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Remote Sensing of Evapotranspiration ET written by Pradeep Wagle and published by MDPI. This book was released on 2019-10-11 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evapotranspiration (ET) is a critical component of the water and energy balances, and the number of remote sensing-based ET products and estimation methods has increased in recent years. Various aspects of remote sensing of ET are reported in the 11 papers published in this book. The major research areas covered by this book include inter-comparison and performance evaluation of widely used one- and two-source energy balance models, a new dual-source model (Soil Plant Atmosphere and Remote Sensing Evapotranspiration, SPARSE), and a process-based model (ETMonitor); assessment of multi-source (e.g., remote sensing, reanalysis, and land surface model) ET products; development or improvement of data fusion frameworks to predict continuous daily ET at a high spatial resolution (field-scale or 30 m) by fusing the advanced spaceborne thermal emission reflectance radiometer (ASTER), the moderate resolution imaging spectroradiometer (MODIS), and Landsat data; and investigating uncertainties in ET estimates using an ET ensemble composed of several land surface models and diagnostic datasets. The effects of the differences between ET products on water resources and ecosystem management were also investigated. More accurate ET estimates and improved understanding of remotely sensed ET products are crucial for maximizing crop productivity while minimizing water losses and management costs.
Download or read book Estimation of Regional Evapotranspiration and Soil Moisture Conditions Using Remotely Sensed Crop Surface Temperatures written by G J R. Soer and published by . This book was released on 1977 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was effected in the framework of the NIWARS investigations on the application of thermal infrared scanning. It concerns the application of thermal infrared scanning for the measurement of aerial heat and water budgets of cropped surfaces.
Download or read book Estimation of Evapotranspiration Under Variable Soil Moisture Situation written by National Institute of Hydrology and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Soil Moisture Data to Estimate Evapotranspiration and Development of a Physically Based Root Water Uptake Model written by Nirjhar Shah and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
