Estimating the effect of water shortage on olive trees by the combination of meteorological and Sentinel-2 data

ABSTRACT

Relative soil water content (RSWC) is widely used to characterize the impact of water stress (WS) on vegetation. In bi-layer ecosystems, such as olive groves, this impact must be primarily estimated for the tree component, which, having greater rooting depth, responds more slowly to WS than understory grass. This complicates the application of methods for RSWC prediction, which must be properly adapted to consider the deeper soil layer influential on olive trees. The current study investigates the modification of a recently proposed RSWC simulation method based on a combination of meteorological and satellite-derived normalized difference vegetation index (NDVI) data. The application of the method to an olive grove in Central Italy requires the estimation of both weather and NDVI contributions affecting solely olive trees, which is carried out through the use of appropriate data processing techniques. The RSWC estimates obtained reasonably reproduce the ground RSWC observations referred to the 1 m soil layer, which are representative of the WS affecting olive trees (r² = 0.795, RMSE = 0.15 and MBE = −0.09). The limits and prospects of this method are finally discussed with particular reference to the possible integration of the RSWC estimates within more complex ecosystem models.

KEYWORDS:

• Sentinel-2 MSI
• rooting depth
• bilayer ecosystems
• soil water content

Acknowledgments

The authors wish to thank the “Istituto Tecnico Agrario” (ITAS) of Florence, for offering the experimental site. The authors are also grateful to the two EuJRS anonymous reviewers for their helpful comments on the first draft of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

Meteorological data are available at https://www.lamma.rete.toscana.it/meteo and the land use map is available at https://land.copernicus.eu/pan-european/corine-land-cover. Sentinel-2 MSI imagery is available at https://sentinel.esa.int/web/sentinel/sentinel-data-access and GoogleEarth images are available at https://earth.google.com/.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

The research was supported by institutional resources.