Hurricane‐Induced Changes in the Everglades National Park Mangrove Forest: Landsat Observations Between 1985 and 2017

Abstract

The Everglades National Park (ENP) has one of the largest mangrove forests in the United States, yet due to lack of data and methods, there has been no multidecadal record of detailed changes in its mangrove forests, not to mention their response to periodic hurricanes. Here, based on remote sensing spectroscopy, multisensor cross calibration, spectral normalization, and pixel unmixing, we develop a stepwise method to map distributions and changes of the ENP mangrove forests and other major wetlands cover types (marshes and hardwood hammocks) over the last three decades. The time series of Landsat-based results indicate statistically significant increasing trend from 1985 to 2017 in the total ENP mangrove coverage with a cumulative increase of 10.2%, which has increased in the inner coastline area but decreased in the outer coastline area. The mangrove coverage also decreased considerably in certain hurricane years (1992, 2005, and 2017), with the largest decrease of 644.9 km 2 (46.5% of the mean mangrove area in normal years) occurring in 1993 after Hurricane Andrew. Yet, these large mangrove die-off areas gradually recovered to prehurricane levels 3-4 years after the passage of major hurricanes. Results also indicate that while the mangrove forests were always damaged by hurricanes, the extent of the damage depended on wind speed, direction, and distance from maximum wind. The findings here could serve as baseline information for future restoration efforts of the ENP ecosystem, and the study also provides a method extendable to other coastal wetland regions.Accurate assessment of the mangrove forests of the ENP and their temporal changes is important to understand how mangrove forests respond to restoration efforts (such as the Comprehensive Everglades Restoration Plan), climate variability, and extreme weather events (such as hurricane perturbations).

Widespread mangrove damage resulting from the 2017 Atlantic mega hurricane season

“…According to this map, there were 2.26 million ha of mangroves within our study region. Based on a previous investigation of mangrove response to hurricanes [25], we considered pixels with a ∆NDVI < −0.2 to represent mangrove damage [34]. In 2017 only, we also calculated mangrove damage as described below from imaging instruments aboard two additional satellites, MODIS Terra and Sentinel 2, to investigate bias resulting from differences in spatial resolution and optical qualities of the instruments (SI appendix).…”

“…While mangroves offer protection from storms, they also incur damage. Specifically, damage may result from several factors including strong winds, flooding, and sediment deposited by storm surge [21][22][23][24][25]. In addition to these storm characteristics, the extent and severity of damage has been shown to depend on mangrove type, canopy height, and landscape context [21,26,27].…”

Vulnerability of Fishery-Based Livelihoods to Extreme Events: Local Perceptions of Damages from Hurricane Irma and Tropical Storm Alberto in Yaguajay, Central Cuba

“…In Cuba, where the present study takes place, a total of 121 hurricanes have been reported between 1791 and 2016; 33 of which have been classified as category 3 or higher (Roura-P erez et al 2018). In combination with increasing temperatures, rising sea levels, and acidification, extreme events have contributed to the disappearance of key habitats (e.g., coral reefs, mangroves, and seagrasses) ( Barton and Casey 2005;Bernal et al 2016;Gardner et al 2005;Han et al 2018;Smith et al 1994). Although their influence in local fisheries remains poorly understood, hurricanes and tropical storms can amplify the effects of anthropogenic stressors such as overfishing with important consequences for the sustainability of fish and human populations alike (Jackson et al 2014;Michener et al 1997;Sainsbury et al 2018).…”

Molecular Level Analysis Reveals Changes in Chemical Composition of Dissolved Organic Matter From South Texas Rivers After High Flow Events

“…In 2017 alone, a total of six major hurricanes (category >3) were formed in Atlantic Ocean, marking the highest number since 2005 and twice of the averaged major hurricane number in the past decade (2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016). Besides the direct impact on the landfall area (e.g., Han et al, 2018), high-flow events after hurricane could subsequently change the hydrology and water quality in subtropical regions (e.g., Nesbit and Mitsch, 2018). Characterized by a semiarid climate and sporadic rainfalls, South Texas is known for very intense precipitation events cropping up within relatively short period of time (Bomar, 1983(Bomar, , 2017Mooney and McClelland, 2012;Bruesewitz et al, 2013;Reyna et al, 2017).…”