Engineering Commons^™

Effects Of Short Season Irrigation On Pasture Yield And Predicting Yield With Sentinel-2 Satellite, Ihsan Bugra Bugdayci

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Deficit irrigation can reduce agriculture water use making additional water available for other uses. This study looked at multi-year impacts of deficit irrigation on pasture yield. The results show that that early irrigation provides the most benefit to cool season pastures and late season irrigation only had small impacts on yield. According to this research, irrigation water can be saved without impacting the yield importantly.

Remote sensing techniques are becoming a part of agriculture. Yield predictions are important for the farmers and others involved with agriculture. In this research, relationships between the normalized difference vegetation index (NDVI) calculated from remotely …

Sharpening Ecostress And Viirs Land Surface Temperature Using Harmonized Landsat-Sentinel Surface Reflectances, Jie Xue, Martha C. Anderson, Feng Gao, Christopher Hain, Liang Sun, Yun Yang, Kyle R. Knipper, William P. Kustas, Alfonso F. Torres-Rua, Mitch Schull

Civil and Environmental Engineering Faculty Publications

Land surface temperature (LST) is a key diagnostic indicator of agricultural water use and crop stress. LST data retrieved from thermal infrared (TIR) band imagery, however, tend to have a coarser spatial resolution (e.g., 100 m for Landsat 8) than surface reflectance (SR) data collected from shortwave bands on the same instrument (e.g., 30 m for Landsat). Spatial sharpening of LST data using the higher resolution multi-band SR data provides an important path for improved agricultural monitoring at sub-field scales. A previously developed Data Mining Sharpener (DMS) approach has shown great potential in the sharpening of Landsat LST using Landsat …

Implications Of Soil And Canopy Temperature Uncertainty In The Estimation Of Surface Energy Fluxes Using Tseb2t And High-Resolution Imagery In Commercial Vineyards, Ayman Nassar, Alfonso F. Torres-Rua, William Kustas, Héctor Nieto, Mac Mckee, Lawrence Hipps, Joseph Alfieri, John H. Prueger, Maria Mar Alsina, Lynn Mckee, Calvin Coopmans, Luis Sanchez, Nick Dokoozlian

Civil and Environmental Engineering Faculty Publications

Estimation of surface energy fluxes using thermal remote sensing–based energy balance models (e.g., TSEB2T) involves the use of local micrometeorological input data of air temperature, wind speed, and incoming solar radiation, as well as vegetation cover and accurate land surface temperature (LST). The physically based Two-source Energy Balance with a Dual Temperature (TSEB2T) model separates soil and canopy temperature (Ts and Tc) to estimate surface energy fluxes including Rn, H, LE, and G. The estimation of Ts and Tc components for the TSEB2T model relies on the linear relationship between the composite land surface temperature and a vegetation index, namely …

To What Extent Does The Eddy Covariance Footprint Cutoff Influence The Estimation Of Surface Energy Fluxes Using Two Source Energy Balance Model And High-Resolution Imagery In Commercial Vineyards?, Ayman Nassar, Alfonso F. Torres-Rua, William Kustas, Héctor Nieto, Mac Mckee, Lawrence Hipps, Joseph Alfieri, John H. Prueger, Maria Mar Alsina, Lynn Mckee, Calvin Coopmans, Louis Sanchez, Nick Dokoozlian

Civil and Environmental Engineering Faculty Publications

Validation of surface energy fluxes from remote sensing sources is performed using instantaneous field measurements obtained from eddy covariance (EC) instrumentation. An eddy covariance measurement is characterized by a footprint function / weighted area function that describes the mathematical relationship between the spatial distribution of surface flux sources and their corresponding magnitude. The orientation and size of each flux footprint / source area depends on the micro-meteorological conditions at the site as measured by the EC towers, including turbulence fluxes, friction velocity (u_star), and wind speed, all of which influence the dimensions and orientation of the footprint. The …

Influence Of Model Grid Size On The Estimation Of Surface Fluxes Using The Two Source Energy Balance Model And Suas Imagery In Vineyards, Ayman Nassar, Alfonso F. Torres-Rua, William Kustas, Hector Nieto, Mac Mckee, Lawrence E. Hipps, David King Stevens, Joseph Alfieri, John Prueger, Maria Mar Alsina, Lynn Mckee, Calvin Coopmans, Luis Sanchez, Nick Dokoozlian

Civil and Environmental Engineering Faculty Publications

Evapotranspiration (ET) is a key variable for hydrology and irrigation water management,with significant importance in drought-stricken regions of the western US. This is particularly true for California, which grows much of the high-value perennial crops in the US. The advent of small Unmanned Aerial System (sUAS) with sensor technology similar to satellite platforms allows for the estimation of high-resolution ET at plant spacing scale for individual fields. However, while multiple efforts have been made to estimate ET from sUAS products, the sensitivity of ET models to different model grid size/resolution in complex canopies, such as vineyards, is still unknown.The variability …