Landsc Ecol (2023) 38:169–183 https://doi.org/10.1007/s10980-022-01540-7
RESEARCH ARTICLE
Prolonged coastal inundation detected with synthetic aperture radar significantly retarded functional recovery of mangroves after major hurricanes Mei Yu · Qiong Gao
Received: 26 July 2022 / Accepted: 29 September 2022 / Published online: 18 October 2022 © The Author(s), under exclusive licence to Springer Nature B.V. 2022
Abstract Context Hurricanes are major threats to coastal mangrove ecosystems. Inundation has been implicitly reported to associate with mangrove damages and mortality. However, there have been no spatial statistical analyses of the impact of inundation on mangrove recovery at landscape scales. Objectives Our objectives are to detect spatiotemporal patterns of inundation after major hurricanes and to explore explicitly the role of inundation in mangrove recovery at landscape scale. Methods Using C-band Synthetic Aperture Radar images, we detected the spatiotemporal pattern of surface flood and derived the spatial distribution of inundation depth under mangrove canopies based on surrounding surface flood and elevation along northern Puerto Rico coasts after major hurricanes in 2017. Based on the Enhanced Vegetation Index, we derived the short-term hurricane impact and the recovery ratio from 2018 to 2021, and analyzed the impact and the recovery of mangrove greenness by means of spatial error models.
Supplementary Information The online version contains supplementary material available at https://doi. org/10.1007/s10980-022-01540-7. M. Yu (*) · Q. Gao Department of Environmental Sciences, University of Puerto Rico, Rio Piedras, San Juan, PR 00926, USA e-mail: meiyu@ites.upr.edu
Results The identification of surface flood reached very high accuracy. The severe impact is significantly explained by greater gust windspeed during the hurricane and lower elevation. More importantly, retarded mangrove greenness recovery is significantly explained by severer impacts, longer and deeper inundation, and heavier hurricane rainfall. Conclusions Spatiotemporal heterogeneity in flood depth plays a significant and essential role in mangrove recovery and delayed mortality after major hurricanes. The derived flood depth turns out to be a better explanator of mangrove recovery than elevation, which highlights importance of landscape hydrology and topography with respect to mangrove response and restoration after major hurricanes. Keywords Inundation · Coastal wetlands · Hurricane · SAR · Flooding detection · Caribbean Introduction Mangrove forests provide essential ecosystem services of water purification, flood mitigation, fisheries, carbon sequestration, and erosion protection for coastal communities (Costanza et al. 2008; Barbier et al. 2011; Gedan et al. 2011). Yet coastal mangroves are facing great anthropogenic threats of deforestation for coastal development, agriculture, and urbanization (Dahl and Stedman 2013), as well as natural threats of rising sea level (Kirwan and Megonigal 2013; Vol.: (0123456789)
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