Coastal Ecosystems Bring Many Benefits but may be Vulnerable to Increasing Intensity Hurricanes

Conference Year

January 2019

Abstract

Mangroves are hugely beneficial tropical ecosystems due to their wide range of ecological and societal functions, but have declined dramatically in most of the world due to human influences. Mangroves in Cuba are a rare case, remaining largely undisturbed by direct human activities, but are not immune to tropical storms and hurricanes. Category V Hurricane Irma (HI, Aug. 2017) swept along 300 km of the northern coast of Cuba, with the eye of the storm just 6-30 km offshore. In addition to physical damage from high winds, inundation by freshwaters for 3 weeks suffocated red mangroves. Here we apply novel remote sensing algorithms for spatio-temporal image compositing to quantify changes in land cover (e.g., mangrove loss) and degradation (e.g., mangrove damage). Google Earth (GE) Engine API cloud was used to composite cloud-free, Sentinel-2 satellite data (10 m, dry season November-March) pre- and post- HI. Changes in land cover (e.g., forest, mangrove, grassland, agriculture/pasture, urban, bare soil) were documented using a random forest classification calibrated with user interpretation of GE imagery predating HI. Validation with user-interpreted points from Planet data products pre- and post- HI showed high accuracy and were further informed by a 2018 field visit. In Caguanes National Park, home to 200 species (24 endemic), we document total mortality in some mangroves and forests and extreme degradation in others using changes in the Normalized Difference Vegetation Index (NDVI). 65% of Mangroves were highly damaged including 44% of all mangroves succumbing to mortality post-HI. Nearly 50% of forests were affected, including damaged canopies (24%), total vegetation loss (6%), and complete opening of canopies (18%). A larger swath of the HI’s path was examined using moderate resolution satellite imagery, confirming the extreme damages to Caguanes National Park proved to be telling of the entire northern coast of Cuba.

Primary Faculty Mentor Name

Gillian Galford

Status

Undergraduate

Student College

Rubenstein School of Environmental and Natural Resources

Program/Major

Environmental Sciences

Primary Research Category

Food & Environment Studies

Abstract only.

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Coastal Ecosystems Bring Many Benefits but may be Vulnerable to Increasing Intensity Hurricanes

Mangroves are hugely beneficial tropical ecosystems due to their wide range of ecological and societal functions, but have declined dramatically in most of the world due to human influences. Mangroves in Cuba are a rare case, remaining largely undisturbed by direct human activities, but are not immune to tropical storms and hurricanes. Category V Hurricane Irma (HI, Aug. 2017) swept along 300 km of the northern coast of Cuba, with the eye of the storm just 6-30 km offshore. In addition to physical damage from high winds, inundation by freshwaters for 3 weeks suffocated red mangroves. Here we apply novel remote sensing algorithms for spatio-temporal image compositing to quantify changes in land cover (e.g., mangrove loss) and degradation (e.g., mangrove damage). Google Earth (GE) Engine API cloud was used to composite cloud-free, Sentinel-2 satellite data (10 m, dry season November-March) pre- and post- HI. Changes in land cover (e.g., forest, mangrove, grassland, agriculture/pasture, urban, bare soil) were documented using a random forest classification calibrated with user interpretation of GE imagery predating HI. Validation with user-interpreted points from Planet data products pre- and post- HI showed high accuracy and were further informed by a 2018 field visit. In Caguanes National Park, home to 200 species (24 endemic), we document total mortality in some mangroves and forests and extreme degradation in others using changes in the Normalized Difference Vegetation Index (NDVI). 65% of Mangroves were highly damaged including 44% of all mangroves succumbing to mortality post-HI. Nearly 50% of forests were affected, including damaged canopies (24%), total vegetation loss (6%), and complete opening of canopies (18%). A larger swath of the HI’s path was examined using moderate resolution satellite imagery, confirming the extreme damages to Caguanes National Park proved to be telling of the entire northern coast of Cuba.