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Samanta S, Hazra S, French JR, Nicholls RJ, Mondal PP. Exploratory modelling of the impacts of sea-level rise on the Sundarbans mangrove forest, West Bengal, India. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166624. [PMID: 37643706 DOI: 10.1016/j.scitotenv.2023.166624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/17/2023] [Accepted: 08/25/2023] [Indexed: 08/31/2023]
Abstract
In this paper we conduct exploratory simulations of the possible evolution of the Indian Sundarbans mangroves to 2100 under a range of future sea-level rise (SLR) scenarios, considering the effects of both inundation and shoreline erosion. The Sea Level Affecting Marshes Model (SLAMM) is used to simulate habitat transitions due to inundation and these outputs are combined with an empirical model of SLR-driven shoreline erosion. A set of plausible climate-induced SLR scenarios are considered, together with delta subsidence and constrained vertical sediment accretion. Significant mangrove decline is found in all cases: the greater the rise in sea level the greater the losses. By the end of the century, the Indian Sundarbans mangroves could lose between 42 % and 80 % of their current area if current management is continued. Managed realignment could offset these losses but at the expense of productive land and the migration of the human population.
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Affiliation(s)
- Sourav Samanta
- School of Oceanographic Studies, Jadavpur University, 188 Raja S. C. Mullick Road, Kolkata 700032, West Bengal, India.
| | - Sugata Hazra
- School of Oceanographic Studies, Jadavpur University, 188 Raja S. C. Mullick Road, Kolkata 700032, West Bengal, India.
| | - Jon R French
- Coastal and Estuarine Research Unit, UCL Department of Geography, University College London, London WC1E 6BT, UK.
| | - Robert J Nicholls
- Tyndall Centre for Climate Change Research, University of East Anglia, Norwich NR4 7TJ, UK.
| | - Partho P Mondal
- School of Oceanographic Studies, Jadavpur University, 188 Raja S. C. Mullick Road, Kolkata 700032, West Bengal, India
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Sahana M, Areendran G, Sajjad H. Assessment of suitable habitat of mangrove species for prioritizing restoration in coastal ecosystem of Sundarban Biosphere Reserve, India. Sci Rep 2022; 12:20997. [PMID: 36470951 PMCID: PMC9723184 DOI: 10.1038/s41598-022-24953-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 11/22/2022] [Indexed: 12/12/2022] Open
Abstract
Mangrove forests being the abode of diverse fauna and flora are vital for healthy coastal ecosystems. These forests act as a carbon sequester and protection shield against floods, storms, and cyclones. The mangroves of the Sundarban Biosphere Reserve (SBR), being one of the most dynamic and productive ecosystems in the world are in constant degradation. Hence, habitat suitability assessment of mangrove species is of paramount significance for its restoration and ecological benefits. The study aims to assess and prioritize restoration targets for 18 true mangrove species using 10 machine-learning algorithm-based habitat suitability models in the SBR. We identified the degraded mangrove areas between 1975 and 2020 by using Landsat images and field verification. The reserve was divided into 5609 grids using 1 km gird size for understanding the nature of mangrove degradation and collection of species occurrence data. A total of 36 parameters covering physical, environmental, soil, water, bio-climatic and disturbance aspects were chosen for habitat suitability assessment. Niche overlay function and grid-based habitat suitability classes were used to identify the species-based restoration prioritize grids. Habitat suitability analysis revealed that nearly half of the grids are highly suitable for mangrove habitat in the Reserve. Restoration within highly suitable mangrove grids could be achieved in the areas covered with less than 75 percent mangroves and lesser anthropogenic disturbance. The study calls for devising effective management strategies for monitoring and conserving the degraded mangrove cover. Monitoring and effective management strategies can help in maintaining and conserving the degraded mangrove cover. The model proves to be useful for assessing site suitability for restoring mangroves. The other geographical regions interested in assessing habitat suitability and prioritizing the restoration of mangroves may find the methodology adopted in this study effective.
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Affiliation(s)
- Mehebub Sahana
- grid.5379.80000000121662407School of Environment, Education and Development, University of Manchester, Oxford Road, Manchester, M13 9PL UK
| | - Gopala Areendran
- grid.511474.20000 0001 0691 3044IGCMC, WWF-India, New Delhi, India
| | - Haroon Sajjad
- grid.411818.50000 0004 0498 8255Department of Geography, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi, India
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Marcinko CLJ, Samanta S, Basu O, Harfoot A, Hornby DD, Hutton CW, Pal S, Watmough GR. Earth observation and geospatial data can predict the relative distribution of village level poverty in the Sundarban Biosphere Reserve, India. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 313:114950. [PMID: 35378347 DOI: 10.1016/j.jenvman.2022.114950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 02/26/2022] [Accepted: 03/20/2022] [Indexed: 05/21/2023]
Abstract
There is increasing interest in leveraging Earth Observation (EO) and geospatial data to predict and map aspects of socioeconomic conditions to support survey and census activities. This is particularly relevant for the frequent monitoring required to assess progress towards the UNs' Sustainable Development Goals (SDGs). The Sundarban Biosphere Reserve (SBR) is a region of international ecological importance, containing the Indian portion of the world's largest mangrove forest. The region is densely populated and home to over 4.4 million people, many living in chronic poverty with a strong dependence on nature-based rural livelihoods. Such livelihoods are vulnerable to frequent natural hazards including cyclone landfall and storm surges. In this study we examine associations between environmental variables derived from EO and geospatial data with a village level multidimensional poverty metric using random forest machine learning, to provide evidence in support of policy formulation in the field of poverty reduction. We find that environmental variables can predict up to 78% of the relative distribution of the poorest villages within the SBR. Exposure to cyclone hazard was the most important variable for prediction of poverty. The poorest villages were associated with relatively small areas of rural settlement (<∼30%), large areas of agricultural land (>∼50%) and moderate to high cyclone hazard. The poorest villages were also associated with less productive agricultural land than the wealthiest. Analysis suggests villages with access to more diverse livelihood options, and a smaller dependence on agriculture may be more resilient to cyclone hazard. This study contributes to the understanding of poverty-environment dynamics within Low-and middle-income countries and the associations found can inform policy linked to socio-environmental scenarios within the SBR and potentially support monitoring of work towards SDG1 (No Poverty) across the region.
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Affiliation(s)
| | - Sourav Samanta
- School of Oceanographic Studies, Jadavpur University, 188, Raja S.C. Mallik Road, Jadavpur, Kolkata, 700032, India.
| | - Oindrila Basu
- School of Oceanographic Studies, Jadavpur University, 188, Raja S.C. Mallik Road, Jadavpur, Kolkata, 700032, India
| | - Andy Harfoot
- School of Geography and Environmental Sciences, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Duncan D Hornby
- School of Geography and Environmental Sciences, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Craig W Hutton
- School of Geography and Environmental Sciences, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Sudipa Pal
- School of Oceanographic Studies, Jadavpur University, 188, Raja S.C. Mallik Road, Jadavpur, Kolkata, 700032, India
| | - Gary R Watmough
- School of Geosciences, Institute of Geography, University of Edinburgh, Drummond Street, Edinburgh, Scotland, United Kingdom; Global Academy of Agriculture and Food Security, University of Edinburgh, Easter Bush Campus, Edinburgh, Scotland, United Kingdom.
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Abstract
Inhabitants of low-lying islands face increased threats due to climate change as a result of their higher exposure and lesser adaptive capacity. Sagar Island, the largest inhabited estuarine island of Sundarbans, is experiencing severe coastal erosion, frequent cyclones, flooding, storm surges, and breaching of embankments, resulting in land, livelihood, and property loss, and the displacement of people at a huge scale. The present study assessed climate change-induced vulnerability and risk for Sagar Island, India, using an integrated geostatistical and geoinformatics-based approach. Based on the IPCC AR5 framework, the proportion of variance of 26 exposure, hazard, sensitivity, and adaptive capacity parameters was measured and analyzed. The results showed that 19.5% of mouzas (administrative units of the island), with 15.33% of the population at the southern part of the island, i.e., Sibpur–Dhablat, Bankimnagar–Sumatinagar, and Beguakhali–Mahismari, are at high risk (0.70–0.80). It has been concluded that the island has undergone tremendous land system transformations and changes in climatic patterns. Therefore, there is a need to formulate comprehensive adaptation strategies at the policy- and decision-making levels to help the communities of this island deal with the adverse impacts of climate change. The findings of this study will help adaptation strategies based on site-specific information and sustainable management for the marginalized populations living in similar islands worldwide.
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River Basin Management Planning in the Republic of Ireland: Past, Present and the Future. WATER 2021. [DOI: 10.3390/w13152074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The River Basin Management Plan (RBMP) is an essential component of the European Union Water Framework Directive that details an integrated approach required to protect, improve and sustainably manage water resources. RBMP were intended to be produced for the periods 2009–2015, 2016–2021 and 2022–2027. However, after two years of delays in the development processes, the Republic of Ireland produced its first RBMP in 2010. The second RBMP cycle was also implemented in 2018 and is expected to run until the end of 2021 to give way to the third RBMP, whose consultation processes have been ongoing since December 2019. This paper contributes to the forthcoming RBMP by assessing stakeholders’ perspectives on the second RBMP through a desk-based review and by conducting interviews with nine institutions (14 interviewees). The qualitatively analysed interviews reveal a broad spectrum of actors associated with water management and governance in the Republic of Ireland through a three-tier governance structure that has been delivered (with amendment) through the first two RBMPs. Organisations such as the An Fóram Uisce|The Water Forum, the Environmental Protection Agency, the Local Authority Waters, and the Agricultural Sustainability Support and Advisory Programme have responsibilities designated in the RBMPs to deliver improved water quality, integrated catchment management, community engagement and awareness-raising. Trust has also been building up among these organisations and other agencies in the water sector. Despite these responsibilities and progress made, the interviews identified communication lapses, ineffective collaboration and coordination among stakeholders and late implementation to be hampering the successful delivery of the second RBMP, in addition to significant pressures acting on water bodies from agricultural activities and urban wastewater treatment. Towards the third RBMP, the paper concludes that optimised water sector finance, enhanced and well-resourced communications, and improved stakeholder collaboration are needed to foster effective and efficient water services delivery and quality. More so, given the cross-cutting impact of the Sustainable Development Goals on water resources and the interconnected relations among the goals, the paper further recommends the integration of the SDGs in the various plans of actions and a co-benefits approach to derive the triple benefits from biodiversity, climate change initiatives and water quality measures.
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Stakeholder Expectations of Future Policy Implementation Compared to Formal Policy Trajectories: Scenarios for Agricultural Food Systems in the Mekong Delta. SUSTAINABILITY 2021. [DOI: 10.3390/su13105534] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The development of a coherent and coordinated policy for the management of large socio-agricultural systems, such as the Mekong delta in southern Vietnam, is reliant on aligning the development, delivery, and implementation of policy on national to local scales. Effective decision making is linked to a coherent, broadly-shared vision of the strategic management of socio-agricultural systems. However, when policies are ambiguous, and at worst contradictory, long-term management and planning can consequently suffer. These potential adverse impacts may be compounded if stakeholders have divergent visions of the current and future states of socio-agricultural systems. Herein we used a transferable, scenario-based methodology which uses a standard quadrant matrix in order to explore both anticipated and idealized future states. Our case study was the Mekong delta. The scenario matrix was based upon two key strategic choices (axis) for the delta, derived from analysis of policy documents, literature, stakeholder engagement, and land use models. These are: (i) who will run agriculture in the future, agri-business or the established commune system; and (ii) to what degree sustainability will be incorporated into production. During a workshop meeting, stakeholders identified that agri-business will dominate future agricultural production in the delta but showed a clear concern that sustainability might consequently be undermined despite policy claims of the contrary. As such, our study highlights an important gap between national expectations and regional perspectives. Our results suggest that the new development plans for the Mekong delta (which comprise a new Master Plan and a new 5-year socio-economic development plan), which emphasize agro-business development, should adopt approaches that address concerns of sustainability as well as a more streamlined policy formulation and implementation that accounts for stakeholder concerns at both provincial and national levels.
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