Download or read book Evapotranspirtation of Subirrigated Vegetation in the Platte River Valley of Nebraska Measurements with Micrometeorological and Remote Sensing Methods written by Blaine L. Blad and published by . This book was released on 1975* with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Remote Sensing in Estimating Evapotranspiration in the Platte River Basin written by B. L. Blad and published by . This book was released on 1976 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evapotranspiration Measurements of Native Vegetation Owens Valley California June 1986 written by Dave Wilson and published by . This book was released on 1992 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimating Evapotranspiration Using Remote Sensing written by Sumatra Chatterjee and published by . This book was released on 2010 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigated water loss by evapotranspiration (ET) from the Palo Verde Irrigation District (PVID) and the Cibola National Wildlife Refuge (CNWR) in southern California bordering the Colorado River collaborating with the United States Bureau of Reclamation (U.S.B.R.). We developed an empirical model to estimate ET for the entire PVID using satellite derived MODIS enhanced vegetation index (EVI), and ground based measurements of solar radiation and vapor pressure. We compared our predictions with U.S.B.R. estimates through statistical cross validation and showed they agree with an error less than 8%. We tested the same model for an alfalfa field inside PVID to check its applicability at a smaller spatial scale. We showed that the same model developed for PVID is the best model for estimating ET for the alfalfa field. We collected data from three Bowen ratio energy balance (BREB) towers installed in the invasive saltcedar (Tamarix spp) dominated riparian zone in the CNWR and a fourth tower in the alfalfa field in PVID. The riparian sites were selected according to different densities of vegetation. We collected data from these sites at various intervals during the period between June 2006 to November 2008. We reduced the errors associated with the Bowen ratio data using statistical procedures taking into account occasional instrument failures and problems inherent in the BREB method. Our results were consistent with vegetation density and estimates from MODIS EVI images. To estimate ET for larger patches of mixed vegetation we modified the crop coefficient equation and represented it in terms of EVI. Using this approach, we scaled the alfalfa field data to the entire PVID and compared the results with U.S.B.R. (2001-2007) estimates. We predicted ET well within the acceptable range established in the literature. We empirically developed ET models for the riparian tower sites to provide accurate point scale ET estimation and scaled for the entire riparian region in CNWR with our modified crop coefficient approach. We investigated the assumptions upon which the Bowen ratio equation is developed. In the presence of turbulence some of the assumptions may not be valid, and the final data may require correction factors.
Download or read book Estimating Plant accessible Water Storage Through Evaluating Evapotranspiration in the Semi arid Western United States Using Eddy covariance Remote Sensing and Spatially Distributed Data written by Joseph Rungee and published by . This book was released on 2019 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: The studies within this dissertation use a suite of long-term flux-tower, remotely sensed, and spatially distributed data to more accurately assess the withdrawal of subsurface plant-accessible water storage during multi-year dry periods, more accurately represent measurements of evapotranspiration across the landscape, and examine how vegetation use of plant-accessible water storage varies along latitudinal and elevation gradients, and with time. First, a suite of flux towers from across the arid and semi-arid western United States were used to assess the response of evapotranspiration under varying climates and vegetation types to drought. Here we found that regions experiencing a Mediterranean climate are substantially more dependent on subsurface storage than those receiving a summer monsoon, but available plant-accessible subsurface water storage in the Mediterranean climates can support evapotranspiration for the entirety of a multi-year dry period at some locations. It was also discovered that a transition from snow to rain could increase dependency vegetation on plant-accessible subsurface water storage by as much as 20\% at energy-limited, snow-dominated sites. Next, measurements of evapotranspiration were distributed across the 14 river basins draining into California$'$s Central Valley. This was performed by expanding on current remotely sensed-based methods to include climatic data and consider vegetation type. This novel approach decreased the root-mean-square error by 31-50\% when compared to methods only using NDVI and was insensitive to the spatial resolution of data used. This product showed that evapotranspiration was greatest in the northern basins, peaking at lower elevations, and decreased in magnitude while peaking at higher elevations as latitude decreased. It was also revealed that runoff was derived in primarily one of two ways in this region, the rain-dominated north where annual rainfall grossly exceeds annual evapotranspiration; and the snowmelt-driven south where most precipitation contributes to high-elevation snowpack in energy-limited areas. Finally, the 14 basins draining into California's Central Valley could be binned into four groups based upon what water-balance components and climatic variables were most highly correlated with changes in subsurface water storage, the northernmost, northern, mid-range and southern basins. The results showed that the southern basins may have already reached a critical threshold in storage drawdown, explaining why tree mortality is so widespread in the region, and that the northern and northernmost basins will likely follow a similar path if measures are not taken to reduce evapotranspiration. The studies in this dissertation provided comprehensive analyses of how evapotranspiration spatially varies and how its response to climate extremes alters the hydrologic cycle. Spatial products are in high demand for water resources and forest management applications, and although quantifying uncertainties remain a challenge, these products provide substantial value to improving our understanding of the water cycle.
Download or read book Evapotranspiration Estimates Using Remote sensing Data Parker and Palo Verde Valleys Arizona and California written by Lee H. Raymond and published by . This book was released on 1986 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measuring Forest Evapotranspiration written by C. Anthony Federer and published by . This book was released on 1970 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Only the soil-water budget and the micrometeorological methods offer any degree of success in measuring forest evapotranspiration. The author discusses these procedures, pointing out the limitations of the soil-water sampling method, but noting that the micrometeorological approach provdies several related methods that offer the best opportunities for accurately measuring evapotranspiration. These methods - mass transfer, eddy correlation, difference, Bowen ration, and combination - are discussed, but less expensive and more reliable instruments must be developed before they can be used routinely for hydrologic research.
Download or read book Evapotranspiration Over Heterogeneous Vegetated Surfaces written by Yuting Yang and published by Springer. This book was released on 2015-03-18 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this work is the development of models to estimate evapotranspiration (ET), investigating the partitioning between soil evaporation and plant transpiration at field and regional scales, and calculating ET over heterogeneous vegetated surfaces. Different algorithms with varying complexities as well as spatial and temporal resolutions are developed to estimate evapotranspiration from different data inputs. The author proposes a novel approach to estimate ET from remote sensing by exploiting the linkage between water and carbon cycles. At the field scale, a hybrid dual source model (H-D model) is proposed. It is verified with field observations over four different ecosystems and coupled with a soil water and heat transfer model, to simulate water and heat transfer in the soil-plant-atmosphere continuum. At the regional scale, a hybrid dual source scheme and trapezoid framework based ET model (HTEM), using remote sensing images is developed. This model is verified with data from the USA and China and the impact of agricultural water-saving on ET of different land use types is analyzed, in these chapters. The author discusses the potential of using a remote sensing ET model in the real management of water resources in a large irrigation district. This work would be of particular interest to any hydrologist or micro-meteorologist who works on ET estimation and it will also appeal to the ecologist who works on the coupled water and carbon cycles. Land evapotranspiration is an important research topic in hydrology, meteorology, ecology and agricultural sciences. Dr. Yuting Yang works at the CSIRO Land and Water, Canberra, Australia.
Download or read book Measurement and Estimation of Evaporation and Evapotranspiration written by M. Gangopadhyaya and published by . This book was released on 1966 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparison of Evapotranspiration Rates in the Platte River in Nebraska written by Harold G. Nagel and published by . This book was released on 1979 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Note: Project No. A-059-NEB.
Download or read book Evapotranspiration written by Salah Er-Raki and published by Nova Science Publishers. This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evapotranspiration (ET) is the total amount of water lost by plant transpiration and soil evaporation. Since about 90% of precipitation received in semi-arid and sub-humid climates is lost to the atmosphere through evapotranspiration, accurate estimations of ET are of crucial need for climate studies, weather forecasts, hydrological surveys, ecological monitoring, and water resource management. This book reviews research on new developments in all areas of evapotranspiration application. It examines the evapotranspiration processes under different environmental and climatic conditions as well as the different methods for modeling and measurement of evapotranspiration at both local and regional scales.
Download or read book Mapping Evapotranspiration Using Satellite remote Sensing Technique written by Ayse Irmak and published by . This book was released on 2010 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Comparison of Techniques for Estimating Potential Evapotranspiration in Nebraska written by Douglas T. Smith and published by . This book was released on 1983 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evapotranspiration Estimation Using Micrometeorological Techniques written by Simona Consoli and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stomatal and Canopy Resistance Plant Physiological Parameters Evapotranspiration and Other Surface Energy Fluxes of Phragmites dominated Riparian Plant Community in the Platte River Basin Nebraska USA written by Isa Kabenge and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Effective water balance analyses require the knowledge of water use rates of riparian zones. Riparian zones usually consist of a variety of vegetation species that have specific transpiration rates. This mosaic of vegetation presents a challenge of how to improve the accuracy to estimate the evaporative fluxes of the riparian zone. The challenge is compounded by the fact that riparian zones are often exposed to large fluctuations in environmental forcing throughout the growing season. Our study presents a robust methodology to measure total evapotranspiration (ETa) and to estimate the growing season transpiration (TRP) for individual vegetation species within a riparian zone through extensive field campaigns conducted in 2009 and 2010. With the espousal of the measured data for individual species, including coverage, stomatal resistance, photosynthetic photon flux density, canopy light interception, leaf area index, plant height, and other within and above-canopy biophysical properties, we scaled up stomatal resistance to canopy resistance to quantify TRT rates of individual specie. The evaporation rates from the riparian zone were also quantified. We developed mixed riparian vegetation evapotranspiration crop coefficients and transpiration crop coefficients for individual species. The total ETa from mixed plant community was 679 mm in 2009 and 982 mm in 2010. In 2009, the seasonal total daytime transpiration for phragmites, cottonwood, and peach-leaf willow were 483, 522 and 431 mm, respectively, and the values for 2010 were higher 550, 655 and 496 mm, respectively. The transpiration was influenced by vegetation phenology (especially increase in LAI and leaf aging) and strongly correlated to irradiance. The average evaporation rate of the riparian zone was 0.81 mm/day in 2009 and 1.7 mm/day in 2010. The seasonal total daytime evaporation was 150 mm in 2009 and 312 mm in 2010. The presence of flood water on the surface and warmer seasonal average temperatures contributed to the high evaporation rates observed in the 2010 growing season.
Download or read book Measurement of Evapotranspiration Using Micrometeorological Methods written by Richard Werner Heine and published by . This book was released on 1973 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evapotranspiration written by Klaus Heimburg and published by . This book was released on 1982 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:
