Engineering Commons^™

Integrating Remote Sensing Of Evapotranspiration With Applied Water To Target Potential Water Conservation Projects In Watersheds, Daniel J. Howes, Stuart Styles

BioResource and Agricultural Engineering

The overall purpose of the project is to develop a methodology for watershed managers to successfully target and release recommendations to growers that could benefit from improved on-farm irrigation management. Initially it was thought that the methodology could rely on remote sensing of actual crop evapotranspiration, effective rainfall estimates, and water application information (pumped volumes and surface water deliveries) to simply evaluate if fields and farms that applied significantly more water than plants needed could be identified. However, it became clear that, in this region specifically, additional information on water quality, crop sensitivity to salinity, and an assumed good irrigation …

Evaluating Net Groundwater Use From Remotely Sensed Evapotranspiration And Water Delivery Information, Daniel J. Howes, Charles M. Burt, Lucas Hoffman

BioResource and Agricultural Engineering

A detailed, comprehensive, and accurate identification of groundwater aquifer properties will likely never be fully achieved because of the high degree of variability and costs that testing involves. Furthermore, accurate estimates of boundary conditions are essential for groundwater modeling so that investigations of improved management scenarios can be conducted. The lack of key input values at the ground surface boundary limits the ability to accurately assess aquifer dynamics. Of major importance is actual evapotranspiration (water consumption or the loss of water to the atmosphere through transpiration and evaporation). The Irrigation Training and Research Center (ITRC) modified remotely sensed satellite imagery …

Grass Referenced Based Vegetation Coefficients For Estimating Evapostranspiration For A Variery Of Natural Vegetation, Daniel J. Howes, Mariana Pasquet

BioResource and Agricultural Engineering

In arid and semi-arid regions, evapotranspiration from vegetation results in the significant utilization of available water. Accurate estimates of evapotranspiration are required for surface and subsurface hydrologic evaluations as well as irrigation district water balance studies. A significant amount of transferable information exists for irrigated agricultural crops through past and current research in the form of grass or alfalfa reference based crop coefficients (Kc) and basal crop coefficients (Kcb). However, transferable evapotranspiration information on natural vegetation is limited. Much of the work was conducted in the early to mid-1900’s and is presented as actual evapotranspiration from the vegetation at the …

Basin-Wide Remote Sensing Of Actual Evapotranspiration And Its Influence On Regional Water Resources Planning, Daniel J. Howes, Charles M. Burt, Kyle Feist

BioResource and Agricultural Engineering

The Irrigation Training & Research Center (ITRC) at Cal Poly State University, San Luis Obispo has been using METRIC to compute actual evapotranspiration from remote sensing sources (namely LandSAT images). The driving force behind this is the increasing need for improved evapotranspiration information on a large scale. A recent study in the Mexicali Valley of Baja California, Mexico utilized the ITRC-modified METRIC procedure to compute the crop and riparian evapotranspiration component of a basin-wide water balance. The resulting comparison between the mass balance computed change in groundwater storage and that computed using groundwater elevation data showed excellent agreement. For water …

Comparison Of Field Level And Regional Actual Etc Values Developed From Remote Sensing And Dual Crop Coefficient Procedure, Daniel J. Howes, Lucas Hoffmann, Franklin Gaudi

BioResource and Agricultural Engineering

Crop evapotranspiration (ETc) estimates are important for regional water planning as well as irrigation scheduling. Traditional ETc computations utilize published crop coefficients (basal) that are adjusted on a daily basis depending on soil water availability (i.e., dual crop coefficient method). Recent advancements include using remote sensing data such as LandSAT combined with a surface energy balance algorithm (METRIC), allowing crop evapotranspiration to be computed for each pixel throughout images taken during the season. There are limitations and advantages for both methods. Comparisons of soil water balance evapotranspiration values to METRIC values for two scenarios in different regions of California have …

California Crop And Soil Evapotranspiration, Charles Burt

BioResource and Agricultural Engineering

The goal of this publication is to provide water users, consultants, water agency personnel, and others throughout California with information that will: (a) help individual water users with irrigation scheduling and system design and (b) help agricultural water agency personnel with water balances and future planning.

The tables in this publication represent the consolidation of results from thousands of annual ET simulations that accounted for crop, rainfall (wet, dry, or “typical”), soil, and irrigation method in each of 13 major ETo zones in California. The annual simulations used daily water balances at the soil surface, crop canopy, and soil root …