Journal article
Using hyperspectral and thermal imagery to monitor stress of Southern California plant species during the 2013–2015 drought
ISPRS journal of photogrammetry and remote sensing, Vol.220, pp.580-592
02/2025
DOI: 10.1016/j.isprsjprs.2025.01.015
Abstract
From 2012 to 2015, California experienced the most severe drought since 1895, causing natural vegetation throughout the state to become water-stressed. With many areas in California being inaccessible and having extremely rugged terrain, remote sensing provides a means for monitoring plant stress across a broad landscape. Airborne hyperspectral and thermal imaging captured the drought in the spring, summer, and fall seasons of 2013 – 2015 across 11,640 km2 of Southern California. Here we provide a large-scale analysis of plant species’ annual and seasonal temperature variability throughout this prolonged drought. We calculated the Temperature Condition Index (TCI) using airborne thermal imagery and a plant species classification map derived from airborne hyperspectral imagery to track response in three dominant species (e.g., Mediterranean grasses and forbs, chamise, and coast live oak) that have different stress adaptation strategies. The annual grasses and forbs showed strong seasonal changes in TCI, which corresponded to the typical green-up, peak biomass in summer, and senescence in the fall. Mediterranean grasses and forbs also had the strongest change in TCI values as the drought progressed from 2013 to 2015, with the months of April and August showing the most pronounced changes. The deeper rooted, native chamise evergreen shrub and coast live oak evergreen, broadleaf tree showed a more minor shift in seasonal and yearly patterns of TCI, but even these very well adapted species showed an increased amount of TCI stress as the drought progressed from 2013 to 2015. Across the study area and image dates, TCI stress was not evenly distributed, but in August 2015 almost the entire region experienced elevated TCI stress. To better understand the environment’s effect on plant stress, we relate topographic attributes to plant stress. Higher TCI values correlated with south or south-southwest facing slopes, while other topographic attributes were weakly correlated with TCI. An increase in elevation had a strong correlation with a decrease in TCI stress, but this relationship weakened as the drought progressed. The synergistic capabilities of hyperspectral and thermal imagery demonstrate that we can monitor the dynamic nature of plant species’ stress temporally and spatially. This work supports improved monitoring of natural landscapes and informing management possibilities, especially for areas prone to continued drought and high risk of wildfires
Details
- Title: Subtitle
- Using hyperspectral and thermal imagery to monitor stress of Southern California plant species during the 2013–2015 drought
- Creators
- Susan K. Meerdink - University of IowaDar A. Roberts - University of California, Santa BarbaraJennifer Y. King - University of California, Santa BarbaraKeely L. Roth - PlanetPaul D. Gader - University of FloridaKelly K. Caylor - University of California, Santa Barbara
- Resource Type
- Journal article
- Publication Details
- ISPRS journal of photogrammetry and remote sensing, Vol.220, pp.580-592
- DOI
- 10.1016/j.isprsjprs.2025.01.015
- ISSN
- 0924-2716
- eISSN
- 1872-8235
- Publisher
- Elsevier B.V
- Grant note
- NASA: NNX12AP08G NASA Earth and Space Science Fellowship (NESSF)Harris Corporation
This project was funded as a NASA Grant NNX12AP08G, HyspIRI discrimination of plant species and functional types along a strong environmental-temperature gradient, and a NASA Earth and Space Science Fellowship (NESSF). The project was also partially supported by the Harris Corporation.
- Language
- English
- Date published
- 02/2025
- Academic Unit
- Geographical and Sustainability Sciences
- Record Identifier
- 9984775022002771
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