Global Assessment Report on Disaster Risk Reduction 2015
Making development sustainable: The future of disaster risk management

background image
Note: BRIICS = Brazil, Russia, India, Indonesia, China, South Africa.
Mangrove conservation and restoration is another area where considerable efforts have been invested, though the results are still mixed. For example, 9,050 hectares of mangroves were planted in West Bengal, India between 1989 and 1995 with a success rate of only 1.5 per cent (Lewis, 2001

Lewis, Roy R. 2001,Mangrove Restoration – Costs and Benefits of Successful Ecological Restoration, In review, Proceedings of the Mangrove Valuation Workshop, Universitity Sains Malaysia, Penang, 4-8 April 2001. Beijer International Institute of Ecological Economics, Stockholm, Sweden.. .
). Mangroves can reduce flood impact by protecting against storm surge, reducing wave heights by up to 50 centimetres and reducing surface waves from wind by more than 75 per cent (McIvor et al., 2013

McIvor, A.L., T. Spencer, I. Möller and M. Spalding. 2013,The response of mangrove soil surface elevation to sea level rise, Natural Coastal Protection Series: Report 3. The Nature Conservancy and Wetlands International.. .
). However, the conditions for successful restoration are not found everywhere.
To address these challenges, hybrid approaches using mangrove reforestation in combination with common structural solutions have also been developed to reduce delta and coastal vulnerability and to create socioeconomic benefits at the same time (Winterwerp et al., 2003). For example, in north-central Java, Indonesia, mangrove belts were widely promoted but did not stabilize eroding coastlines and could not be restored successfully due to the morphology of the shoreline.
Instead, the coast continued to degrade at an alarming rate (Winterwerp et al., 2014

Winterwerp, Han, Bregje van Wesenbeeck, Jan van Dalfsen, Femke Tonneijck, Apri Astra, Stefan Verschure and Pieter van Eijk. 2014,A sustainable solution for massive coastal erosion in Central Java - Towards Regional Scale Application of Hybrid Engineering, Discussion paper. Deltares and Wetlands International.. .
). However, a combination of permeable structures on the one hand and engineering techniques on the other enabled enough sediment to accumulate, thus creating sufficient elevation for the mangroves to colonize naturally (ibid.).
While anecdotal examples of successful (and unsuccessful) approaches to ecosystem and environmental management abound, it is difficult to measure their global impact. However, significant investments in restoring and protecting natural capital are being made, and they have proved to be effective in reversing the loss of biodiversity and ecosystem decline at the local level (OECD, 2012

OECD (Organisation for Economic Co-operation and Development). 2012,OECD Environmental Outlook to 2050: The consequences of Inaction, Paris: OECD Publishing.. .
). For example, efforts in reforestation and natural forest regeneration, particularly in OECD countries and emerging economies, are projected to show results from 2020 onwards, with a significant increase in overall forest cover projected to continue up to 2050 (Figure 12.8).
Figure 12.8 Global forest area change, 2010-2050
(Source: OECD, 2012

OECD (Organisation for Economic Co-operation and Development). 2012,OECD Environmental Outlook to 2050: The consequences of Inaction, Paris: OECD Publishing.. .
Previous page Previous Section  
Contact us  |  Disclaimer  |  Our Partners  |  References  |  Acknowledgements  |  PreventionWeb |  WCDRR  |  © United Nations 2015.