Remote Sensing Tools for Monitoring Water Requirements and Water Stress in Vineyards and Fruit Trees
Dr. Samuel Ortega-Farías, Ph.D.
ABSTRACT
The main agricultural areas of Chile will face a significant reduction of rainfall (between 20-40%) due to global climate change. Also, Chile is periodically affected by the climatic phenomenon of “La Niña” (ENSO), which has produced important droughts and economic losses in most of the agricultural areas. Under these conditions, sophisticated irrigation water management will be required to optimize water productivity (kg m-3) and to maintain sufficient levels of yield and quality of wine and fruits. In this regard, the objective of this paper is to describe remote sensing tools for monitoring water requirements (or evapotranspiration, ET) and plant water stress in vineyards and fruit orchards. The description includes the evaluation of METRIC (mapping evapotranspiration at high resolution with internalized calibration) model to generate maps with the spatial distribution of crop coefficients (Kc) and ET of vineyards and fruit orchards using satellite images. In this case, validation indicated that METRIC was able to estimate ET and Kc with errors of 9 and 10%, respectively. Also, the presentation includes the validation of a remote sensing energy balance (RSEB) algorithm for estimating vine ET using multispectral and thermal sensors placed aboard an Unmanned Aerial Vehicle (UAV). Results indicated that RSEB algorithm overestimated ET by about 13%, with a root mean squared error (RMSE) and mean absolute error (MAE) of 0.43 and 0.29 mm d-1. Finally, the presentation will describe a preliminary study about the estimation of vine and fruit tree water status using spectral indices obtained from a six-band multispectral camera placed aboard a UAV. This technology is a suitable decision-making tool for digital agriculture.
BIOSKETCH
Dr. Samuel Ortega-Farias obtained a Bachelor’s degree in Agronomy Science (viticulture and enology) at the Catholic University (Chile). He obtained both Master and Ph.D. degrees from Oregon State University (USA) with a major area in bio-mathematical modeling and soil–water–plant–atmosphere relationship. He is currently working as a professor at the Agronomy School, Faculty of Agricultural Sciences, University of Talca (Chile). Furthermore, he is the Director of the Research and Extension Center for Irrigation and agroclimatology (CITRA). His research has focused on regulated deficit irrigation, sustainable water management, and mapping evapotranspiration and plant water status using remote sensing imagery obtained from unmanned aerial vehicles (UAV) and satellite remote sensing platforms. Finally, Dr. Ortega-Farias is the Editor-in-Chief of the Journal Irrigation Science (Springer Nature).