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Full-Text Articles in Engineering

Assessment Of Different Methods For Shadow Detection In High-Resolution Optical Imagery And Evaluation Of Shadow Impact On Calculation Of Ndvi And Evapotranspiration, Mahyar Aboutalebi, Alfonso F. Torres-Rua, William P. Kustas, Héctor Nieto, Calvin Coopmans, Mac Mckee Dec 2018

Assessment Of Different Methods For Shadow Detection In High-Resolution Optical Imagery And Evaluation Of Shadow Impact On Calculation Of Ndvi And Evapotranspiration, Mahyar Aboutalebi, Alfonso F. Torres-Rua, William P. Kustas, Héctor Nieto, Calvin Coopmans, Mac Mckee

AggieAir Publications

Significant efforts have been made recently in the application of high-resolution remote sensing imagery (i.e., sub-meter) captured by unmanned aerial vehicles (UAVs) for precision agricultural applications for high-value crops such as wine grapes. However, at such high resolution, shadows will appear in the optical imagery effectively reducing the reflectance and emission signal received by imaging sensors. To date, research that evaluates procedures to identify the occurrence of shadows in imagery produced by UAVs is limited. In this study, the performance of four different shadow detection methods used in satellite imagery was evaluated for high-resolution UAV imagery collected over a California …


Estimating Actual Evapotranspiration From Stony-Soils In Montane Ecosystems, Kshitij Parajuli, Scott B. Jones, David G. Tarboton, Gerald N. Flerchinger, Lawrence E. Hipps, L. Niel Allen, Mark S. Seyfried Nov 2018

Estimating Actual Evapotranspiration From Stony-Soils In Montane Ecosystems, Kshitij Parajuli, Scott B. Jones, David G. Tarboton, Gerald N. Flerchinger, Lawrence E. Hipps, L. Niel Allen, Mark S. Seyfried

Plants, Soils, and Climate Faculty Publications

Quantification of evapotranspiration (ET) is crucial for understanding the water balance and for efficient water resources planning. Agricultural settings have received most attention regarding ET measurements while less knowledge is available for actual ET (ETA) in natural ecosystems, many of which have soils containing significant amounts of stones. This study is focused on modelling ETA from stony soil, particularly in montane ecosystems where we estimate the contribution of stone content on water retention properties in soil. We employed a numerical model (HYDRUS-1D) to simulate ETA in natural settings in northern Utah and southern Idaho during the …


Hydrologic Observation, Model, And Theory Congruence On Evapotranspiration Variance: Diagnosis Of Multiple Observations And Land Surface Models, Ruijie Zeng, Ximing Cai Oct 2018

Hydrologic Observation, Model, And Theory Congruence On Evapotranspiration Variance: Diagnosis Of Multiple Observations And Land Surface Models, Ruijie Zeng, Ximing Cai

Civil and Environmental Engineering Faculty Publications

This paper reconciles the state-of-the-art observations and simulations of evapotranspiration (ET) temporal variability through a diagnostic framework composed of an observation-model-theory triplet. Specifically, a confirmed theoretical tool, Evapotranspiration Temporal VARiance Decomposition (EVARD), is used as a benchmark to estimate ET monthly variance (σ2ET) across the contiguous United States (CONUS) with inputs including hydroclimatic observations, Gravity Recovery and Climate Experiment-based terrestrial water storage, four observation-based products (ETRSUW by the University of Washington, ETRSMOD16 from MOD16 Global Terrestrial ET Data Set, ETFLUXNET upscaled from of fluxtower observations, and ETGLEAM from Global Land Evaporation Amsterdam Model), …


The Grape Remote Sensing Atmospheric Profile And Evapotranspiration Experiment, William P. Kustas, Martha C. Anderson, Joseph G. Alfieri, Kyle Knipper, Alfonso F. Torres-Rua, Christopher K. Parry, Hector Nieto, Nurit Agam, William A. White, Feng Gao, Lynn Mckee, John H. Prueger, Lawrence E. Hipps, Sebastian A. Los, Maria Mar Alsina, Luis Sanchez, Brent Sams, Nick Dokoozlian, Mac Mckee, Scott B. Jones, Yun Yang, Tiffany G. Wilson, Fangni Lei, Andrew Mcelrone, Josh L. Heitman, Adam M. Howard, Kirk Post, Forrest Melton, Christopher Hain Oct 2018

The Grape Remote Sensing Atmospheric Profile And Evapotranspiration Experiment, William P. Kustas, Martha C. Anderson, Joseph G. Alfieri, Kyle Knipper, Alfonso F. Torres-Rua, Christopher K. Parry, Hector Nieto, Nurit Agam, William A. White, Feng Gao, Lynn Mckee, John H. Prueger, Lawrence E. Hipps, Sebastian A. Los, Maria Mar Alsina, Luis Sanchez, Brent Sams, Nick Dokoozlian, Mac Mckee, Scott B. Jones, Yun Yang, Tiffany G. Wilson, Fangni Lei, Andrew Mcelrone, Josh L. Heitman, Adam M. Howard, Kirk Post, Forrest Melton, Christopher Hain

AggieAir Publications

Particularly in light of California’s recent multiyear drought, there is a critical need for accurate and timely evapotranspiration (ET) and crop stress information to ensure long-term sustainability of high-value crops. Providing this information requires the development of tools applicable across the continuum from subfield scales to improve water management within individual fields up to watershed and regional scales to assess water resources at county and state levels. High-value perennial crops (vineyards and orchards) are major water users, and growers will need better tools to improve water-use efficiency to remain economically viable and sustainable during periods of prolonged drought. To develop …


Evaluation Of Tseb Turbulent Fluxes Using Different Methods For The Retrieval Of Soil And Canopy Component Temperatures From Uav Thermal And Multispectral Imagery, Héctor Nieto, William P. Kustas, Alfonso F. Torres-Rúa, Joseph G. Alfieri, Feng Gao, Martha C. Anderson, W. Alex White, Lisheng Song, María Del Mar Alsina, John H. Prueger, Mac Mckee, Manal Elarab, Lynn G. Mckee Sep 2018

Evaluation Of Tseb Turbulent Fluxes Using Different Methods For The Retrieval Of Soil And Canopy Component Temperatures From Uav Thermal And Multispectral Imagery, Héctor Nieto, William P. Kustas, Alfonso F. Torres-Rúa, Joseph G. Alfieri, Feng Gao, Martha C. Anderson, W. Alex White, Lisheng Song, María Del Mar Alsina, John H. Prueger, Mac Mckee, Manal Elarab, Lynn G. Mckee

AggieAir Publications

The thermal-based Two-Source Energy Balance (TSEB) model partitions the evapotranspiration (ET) and energy fluxes from vegetation and soil components providing the capability for estimating soil evaporation (E) and canopy transpiration (T). However, it is crucial for ET partitioning to retrieve reliable estimates of canopy and soil temperatures and net radiation, as the latter determines the available energy for water and heat exchange from soil and canopy sources. These two factors become especially relevant in row crops with wide spacing and strongly clumped vegetation such as vineyards and orchards. To better understand these effects, very high spatial resolution remote-sensing data from …


Advancing Methods To Quantify Actual Evapotranspiration In Stony Soil Ecosystems, Kshitij Parajuli Aug 2018

Advancing Methods To Quantify Actual Evapotranspiration In Stony Soil Ecosystems, Kshitij Parajuli

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water is undeniably among the most important natural resources and the most critical in semi-arid regions like the Intermountain West of the United States. Such regions are characterized by low precipitation, the majority of which is transferred to the atmosphere from the soil and vegetation as evapotranspiration (ET). Quantification of ET is thus crucial for understanding the balance of water within the region, which is important for efficiently planning the available water resources. This study was motivated towards advancing the estimation of actual ET (ETA) in mountain ecosystems, where the variation in different types of vegetation and non-uniformity …