Storm surge, not wind, caused mangrove dieback in southwest Florida following Hurricane Irma

AbstractMangroves buffer inland ecosystems from hurricane winds and storm surge. However, their ability to withstand harsh cyclone conditions depends on plant resilience traits and geomorphology. Using airborne lidar and satellite imagery collected before and after Hurricane Irma, we estimated that 62% of mangroves in southwest Florida suffered canopy damage, with largest impacts in tall forests (>10 m). Mangroves on well-drained sites (83%) resprouted new leaves within one year after the storm. By contrast, in poorly-drained inland sites, we detected one of the largest mangrove diebacks on record (10,760 ha), triggered by Irma. We found evidence that the combination of low elevation (median = 9.4 cm asl), storm surge water levels (>1.4 m above the ground surface), and hydrologic isolation drove coastal forest vulnerability and were independent of tree height or wind exposure. Our results indicated that storm surge and ponding caused dieback, not wind. Tidal restoration and hydrologic management in these vulnerable, low-lying coastal areas can reduce mangrove mortality and improve resilience to future cyclones.

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The Impact of Hurricane Irma on Our Community and the Collier Mosquito Control District's Mission

Journal of the American Mosquito Control Association ◽

10.2987/19-6876.1 ◽

2020 ◽

Vol 36 (2s) ◽

pp. 11-14

Author(s):

Robin A. King ◽

Rebecca Heinig ◽

Patrick Linn ◽

Keira J. Lucas

Keyword(s):

Mosquito Control ◽

Electrical Power ◽

Southwest Florida ◽

Disease Vector ◽

Collier County ◽

Mosquito Management ◽

The Impact ◽

Integrated Mosquito Management ◽

Hurricane Irma ◽

Subtropical Environment

ABSTRACT The Collier Mosquito Control District, located in southwest Florida, is uniquely positioned in a subtropical environment between the Gulf of Mexico and Everglades National Park. The District's mission is focused on the control of disease vector and nuisance mosquitoes in Collier County, which is accomplished through integrated mosquito management. Hurricane Irma made landfall in the county on September 10, 2017, leaving in its wake tremendous property and infrastructure damage, and it also disrupted communications and airport operations. These factors greatly affected the District's operations and its ability to meet its mission. In addition, the lengthy loss of electrical power forced most residents outdoors, increasing their exposure to mosquitoes. From challenges in completing poststorm treatments to outdated policies that caught us off-guard, the event prompted a new hurricane policy and plan to ensure improved preparedness for the next natural disaster. The poststorm environment also provided a rich foundation for research into mosquito populations after tropical disturbances of this scale. Here we report the impact on the District's aerial mosquito control operations, changes to internal policies, and mosquito population abundance following Hurricane Irma.

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Mangrove Damage, Delayed Mortality, and Early Recovery Following Hurricane Irma at Two Landfall Sites in Southwest Florida, USA

Estuaries and Coasts ◽

10.1007/s12237-019-00564-8 ◽

2019 ◽

Vol 43 (5) ◽

pp. 1104-1118 ◽

Cited By ~ 13

Author(s):

Kara R. Radabaugh ◽

Ryan P. Moyer ◽

Amanda R. Chappel ◽

Emma E. Dontis ◽

Christine E. Russo ◽

...

Keyword(s):

Early Recovery ◽

Southwest Florida ◽

Delayed Mortality ◽

Hurricane Irma

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Evacuee Perception of Geophysical Hazards for Hurricane Irma

Weather Climate and Society ◽

10.1175/wcas-d-18-0019.1 ◽

2019 ◽

Vol 11 (1) ◽

pp. 217-227 ◽

Cited By ~ 5

Author(s):

Jason Senkbeil ◽

Jennifer Collins ◽

Jacob Reed

Keyword(s):

Wind Speed ◽

Storm Surge ◽

Wind Speeds ◽

Wind Gusts ◽

Different Types ◽

High Concern ◽

Rest Areas ◽

The Mean ◽

Atlantic Hurricanes ◽

Hurricane Irma

Abstract Hurricane Irma was one of the strongest Atlantic hurricanes in history before landfall and caused a large evacuation. A total of 155 evacuees at interstate rest areas were asked to rank their concern about damage at their residence for six different geophysical hurricane hazards. Additionally, they were asked about their perceived maximum wind speeds (PMWS) and the wind speeds at which they thought damage would occur (DW) at their residence. These wind speeds were then compared to the actual peak wind gusts (APG) nearest to each resident’s location. Results show a significantly greater concern for wind and storm size, compared to other hazards (tornadoes, rainfall/flooding, storm surge, falling trees). The mean PMWS of evacuees was greater than the mean APG, suggesting widespread misperception of wind speeds. Furthermore, the mean APG was less than the mean DW, and the mean PMWS was also higher than the DW. Additional tests found no significant differences in wind perception between residents with previous storm experiences and no experience, and no significant differences between those who resided in mandatory evacuation zip codes and those who did not. These results suggest that wind speed risk is poorly understood, even though it is a high concern for evacuees from hurricanes. The communication of wind speed risk in forecasts should possibly be modified by placing greater emphasis on postlandfall impacts, wind speed decay after landfall, and wind speeds that cause damage to different types of residences.

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Understanding the Effects of Wind Intensity, Forward Speed, Pressure and Track on Generation and Propagation of Hurricane Irma Surges around Florida

Journal of Marine Science and Engineering ◽

10.3390/jmse9090963 ◽

2021 ◽

Vol 9 (9) ◽

pp. 963

Author(s):

Abram Musinguzi ◽

Madinah Shamsu ◽

Muhammad K. Akbar ◽

Jason G. Fleming

Keyword(s):

Storm Surge ◽

West Coast ◽

Florida Keys ◽

Offshore Wind ◽

Forward Speed ◽

The West ◽

Onshore Wind ◽

Hurricane Wind ◽

Wind Intensity ◽

Hurricane Irma

In this study, it is demonstrated that hurricane wind intensity, forward speed, pressure, and track play an important role on the generation and propagation of coastal storm surges. Hurricane Irma, which heavily impacted the entire Florida peninsula in 2017, is used to study the storm surge sensitivity to varying storm characteristics. Results show that the west coast experiences a negative surge due to offshore wind of the approaching storm, but the positive surge returns after the hurricane eye passes over a location and wind became onshore. In the west coast peak, surges are intensified by an increase in onshore wind intensity and forward speed. In the Florida Keys, peak surges are intensified by an increase in wind intensity, a decrease in forward speed and a decrease in pressure. In southeast and east Florida, peak surges are intensified by decrease in pressure, although overall surges are less significant as the water can slide along the coastline. In the recessed coastline of Georgia-Carolinas, maximum surge is elevated by an increase in onshore wind intensity. Shifting the track westward increases peak surges on the west coast, while shifting the track eastward increases peak surge on the east coast. The results demonstrate a new understanding about the sensitivity of surge to varying parametric conditions and the importance of considering changes in the coastline orientation in storm surge predictions.

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Integrating Evacuation and Storm Surge Modeling Considering Potential Hurricane Tracks: The Case of Hurricane Irma in Southeast Florida

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10100661 ◽

2021 ◽

Vol 10 (10) ◽

pp. 661

Author(s):

Mahyar Ghorbanzadeh ◽

Linoj Vijayan ◽

Jieya Yang ◽

Eren Erman Ozguven ◽

Wenrui Huang ◽

...

Keyword(s):

Storm Surge ◽

Element Model ◽

South Florida ◽

Individual Decision ◽

Evacuation Modeling ◽

Case Study Analysis ◽

Storm Surge Modeling ◽

Shelter Availability ◽

Hurricane Irma

Hurricane Irma, in 2017, made an unusual landfall in South Florida and the unpredictability of the hurricane’s path challenged the evacuation process seriously and left many evacuees clueless. It was likely to hit Southeast Florida but suddenly shifted its path to the west coast of the peninsula, where the evacuation process had to change immediately without any time for individual decision-making. As such, this study aimed to develop a methodology to integrate evacuation and storm surge modeling with a case study analysis of Irma hitting Southeast Florida. For this purpose, a coupled storm surge and wave finite element model (ADCIRC+SWAN) was used to determine the inundation zones and roadways with higher inundation risk in Broward, Miami-Dade, and Palm Beach counties in Southeast Florida. This was fed into the evacuation modeling to estimate the regional clearance times and shelter availability in the selected counties. Findings show that it takes approximately three days to safely evacuate the populations in the study area. Modeling such integrated simulations before the hurricane hit the state could provide the information people in hurricane-prone areas need to decide to evacuate or not before the mandatory evacuation order is given.

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MDPrePost-Net: A Spatial-Spectral-Temporal Fully Convolutional Network for Mapping of Mangrove Degradation Affected by Hurricane Irma 2017 Using Sentinel-2 Data

Remote Sensing ◽

10.3390/rs13245042 ◽

2021 ◽

Vol 13 (24) ◽

pp. 5042

Author(s):

Ilham Jamaluddin ◽

Tipajin Thaipisutikul ◽

Ying-Nong Chen ◽

Chi-Hung Chuang ◽

Chih-Lin Hu

Keyword(s):

Coastal Zone ◽

Satellite Images ◽

Experimental Results ◽

Convolutional Network ◽

Fully Convolutional Network ◽

Southwest Florida ◽

Mangrove Area ◽

Mangrove Degradation ◽

Hurricane Irma ◽

Sentinel 2

Mangroves are grown in intertidal zones along tropical and subtropical climate areas, which have many benefits for humans and ecosystems. The knowledge of mangrove conditions is essential to know the statuses of mangroves. Recently, satellite imagery has been widely used to generate mangrove and degradation mapping. Sentinel-2 is a volume of free satellite image data that has a temporal resolution of 5 days. When Hurricane Irma hit the southwest Florida coastal zone in 2017, it caused mangrove degradation. The relationship of satellite images between pre and post-hurricane events can provide a deeper understanding of the degraded mangrove areas that were affected by Hurricane Irma. This study proposed an MDPrePost-Net that considers images before and after hurricanes to classify non-mangrove, intact/healthy mangroves, and degraded mangroves classes affected by Hurricane Irma in southwest Florida using Sentinel-2 data. MDPrePost-Net is an end-to-end fully convolutional network (FCN) that consists of two main sub-models. The first sub-model is a pre-post deep feature extractor used to extract the spatial–spectral–temporal relationship between the pre, post, and mangrove conditions after the hurricane from the satellite images and the second sub-model is an FCN classifier as the classification part from extracted spatial–spectral–temporal deep features. Experimental results show that the accuracy and Intersection over Union (IoU) score by the proposed MDPrePost-Net for degraded mangrove are 98.25% and 96.82%, respectively. Based on the experimental results, MDPrePost-Net outperforms the state-of-the-art FCN models (e.g., U-Net, LinkNet, FPN, and FC-DenseNet) in terms of accuracy metrics. In addition, this study found that 26.64% (41,008.66 Ha) of the mangrove area was degraded due to Hurricane Irma along the southwest Florida coastal zone and the other 73.36% (112,924.70 Ha) mangrove area remained intact.

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Automated High-Resolution Time Series Mapping of Mangrove Forests Damaged by Hurricane Irma in Southwest Florida

Remote Sensing ◽

10.3390/rs12111740 ◽

2020 ◽

Vol 12 (11) ◽

pp. 1740

Author(s):

Matthew J. McCarthy ◽

Brita Jessen ◽

Michael J. Barry ◽

Marissa Figueroa ◽

Jessica McIntosh ◽

...

Keyword(s):

Time Series ◽

High Resolution ◽

Land Cover ◽

Satellite Imagery ◽

Large Scale ◽

Detection Methods ◽

Mangrove Forests ◽

Wetland Ecosystems ◽

Southwest Florida ◽

Hurricane Irma

In September of 2017, Hurricane Irma made landfall within the Rookery Bay National Estuarine Research Reserve of southwest Florida (USA) as a category 3 storm with winds in excess of 200 km h−1. We mapped the extent of the hurricane’s impact on coastal land cover with a seasonal time series of satellite imagery. Very high-resolution (i.e., <5 m pixel) satellite imagery has proven effective to map wetland ecosystems, but challenges in data acquisition and storage, algorithm training, and image processing have prevented large-scale and time-series mapping of these data. We describe our approach to address these issues to evaluate Rookery Bay ecosystem damage and recovery using 91 WorldView-2 satellite images collected between 2010 and 2018 mapped using automated techniques and validated with a field campaign. Land cover was classified seasonally at 2 m resolution (i.e., healthy mangrove, degraded mangrove, upland, soil, and water) with an overall accuracy of 82%. Digital change detection methods show that hurricane-related degradation was 17% of mangrove forest (~5 km2). Approximately 35% (1.7 km2) of this loss recovered one year after Hurricane Irma. The approach completed the mapping approximately 200 times faster than existing methods, illustrating the ease with which regional high-resolution mapping may be accomplished efficiently.

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