Are the Sundarbans, the World's largest mangroves region under threat?—An ecosystem‐based geospatial approach to assess changes past, present, and future in relation to natural and human‐induced factors

Abstract

The World's most extensive mangrove region, the Sundarbans ecosystem, is highly biodiverse but severely stressed. Past, present, and future potential changes in Sundarbans mangroves have been assessed from multi-temporal satellite data of 1980, 2000, and 2020, elevation data, and topographical maps using geospatial techniques, digital shoreline analysis system, land change modelling, and ground truth verification. The mangrove loss was 16,025 ha between 1980 and 2020 and is predicted to be 22,286 ha between 2020 and 2050. Major changes were observed in mangroves, waterbodies, mudflats, agriculture, and aquaculture. The shoreline change by endpoint rate indicated the erosion rate by 5.81 m yr À1 in 2000-2020 compared to À0.90 m yr À1 in 1980-2000. The weighted linear regression indicated the average erosion and accretion rate of À5.96 m-yr À1 and 4.92 m yr À1 , respectively, with erosion in 76% of transects and accretion in the remaining 24% between 1980 and 2020.A sea-level rise by 1 m will inundate 17,486 ha of mangroves. The finding revealed the dynamic nature of mangroves, past and expected future loss, the severely eroding transects, hotspots, and the consequences of mangrove loss on depending the population. As fringe mangroves will be at greater risk, speedy measures are needed to stabilize the highly eroding regions.climate change vulnerability, geographical information system (GIS), natural and anthropogenic factors, sea-level rise, shoreline change, Sundarban mangroves | INTRODUCTIONMangroves are carbon-rich ecosystems that thrive in intertidal coastal saline zones or brackishwater. They protect the coast from hurricanes, tsunamis, and shoreline erosion, serve as breeding grounds for many shrimps and finfishes, offer medicine, firewood, food, and building construction materials for the local population (Dasgupta et al., 2019;Giri et al., 2007;Menéndez et al., 2020). Despite their importance for maintaining biodiversity, coastal ecology, and supporting local livelihoods, mangroves are greatly threatened across the globe (Friess et al., 2019). The development of satellite, remote sensing, and geospatial analysis software have helped researchers and environmentalists to assess mangrove dynamics and deforestation. Due to timeseries data generation capability, remote sensing science has become

Impact of Climate Change: Whispering from the Sundarbans Mangrove of Bangladesh

“…Most of the rivers of Bangladesh flow from north to south, silting up the mangroves delta and draining into the Bay of Bengal (Bandyopadhyay et al 2023;van Maren et al 2023). The mangrove is a transitional area between the freshwater rivers originating from the Ganges and the Bay of Bengal (Das 2023;Jayanthi et al 2023;Subramanian et al 2023). The ecosystems as well as the luxuriant biodiversity of Sundarbans have strong interactions with marine environments (Sarkar & Bhattacharya 2003;Rahman 23 c, d, e, f).…”

How Does Increased Salination Jeopardize the Floral Diversity of the Sundarbans Mangrove of Bangladesh?

“…Most of the rivers of Bangladesh flow from north to south, silting up the mangroves delta and draining into the Bay of Bengal (van Maren et al 2023;Bandyopadhyay et al 2023). The mangrove is a transitional territory between the freshwater rivers originating from the Ganges and the Bay of Bengal (Das 2023;Subramanian et al 2023;Jayanthi et al 2023;).…”