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FEATURE: The vital role of ecosystems in reducing risk from disasters

With losses from major disasters increasing, we should be investing in ecosystems that protect people and infrastructure, says CDKN’s Maliza van Eeden

The last ten years have seen huge losses from disasters such as the 2004 East Asian tsunami, hurricanes Katrina and Sandy, and earthquakes in Haiti and Pakistan. Steady progress has been made in decreasing the number of lives lost from disasters, particularly from improvements in early warning systems. However, direct economic losses from disasters have increased over the last 40 years due to the transformation of the global economy.

According to the UN’s 2013 Global Assessment Report on Disaster Risk Reduction (DRR), economic losses amount to hundreds of billions of dollars annually and are projected to double by 2030. To this should be added the cost of the numerous small, “everyday” disasters that affect people’s lives and assets, but which do not make it into newspaper headlines or onto the agendas of donor meetings.

It seems logical that healthy ecosystems would help to protect people from the impacts of disaster. They increase resilience levels, deliver development benefits and help communities adapt to climate change, all of which should help vulnerable people cope with the impacts of more frequent and intense disasters. Yet the role of ecosystems in disaster risk reduction does not have the profile it deserves, considering its status as a “no regrets” development option.

The Hyogo Framework for Action (HFA), the first international plan to substantially reduce disaster losses by 2015, outlines five priorities for action. Sustainable ecosystems and environmental management is listed under Priority 4, to “reduce the underlying risk factors”. This is the priority where least progress has been made so far, according to the HFA’s mid-term review. Despite its direct impact on each of the HFA’s priority areas, ecosystems are also not officially recognised as a crosscutting issue.

According to Professor Nick Brown of Oxford University’s Department of Plant Sciences, several factors present barriers to the uptake of “green” DRR solutions. Firstly, the links between ecosystems, resilience and DRR is an emerging area and understanding of their inter-connectivity is still poor. Because of the diversity of ecosystems, geophysical conditions and hazards, it is also difficult to extrapolate general solutions. Secondly, ecosystems approaches can take decades to deliver their full risk reduction benefit, while political cycles are more concerned with short-term gains.

Professor Wadid Erian, a lead author for the Intergovernmental Panel on Climate Change (IPCC), said at the recent Global Platform for Disaster Risk Reduction in Geneva, Switzerland, that “the most effective adaptation and disaster risk reduction programmes are those that offer development benefits in the short term and reduce vulnerability in the long term”. Perhaps part of the answer, then, is to emphasise the short-term development gains from ecosystem services to buy time for the long-term benefits to take effect.

Another part of the problem is that the value of ecosystems in mitigating impacts from disasters has been hard to measure. However, this is now changing. At the Global Platform for DRR, the Partnership for Environment and Disaster Risk Reduction (PEDRR) launched a new book entitled The Role of Ecosystems in Disaster Risk Reduction.(1) PEDRR is an alliance of UN agencies, NGOs and specialist institutes that promotes the implementation of ecosystems-based DRR. The book is a compilation of articles by DRR practitioners and academics setting out the state of our knowledge of ecosystems-based approaches to DRR, based on studies from across the globe. It presents evidence quantifying the contribution of ecosystems compared to other, more conventional, infrastructure solutions.

An example from the Swiss Alps illustrates the value of so-called “protection forests” in safeguarding people, assets and infrastructure from avalanches, rock falls and landslides .(2) Forests are an integral part of Switzerland’s risk management strategy and are becoming increasingly important with the influx of people and assets to previously inaccessible mountainous areas through better transport and the growth in tourism. Protection forests provide both direct protection (for example, by preventing the homogenous build-up of snow that leads to avalanches) and indirect protection (where forests in a river catchment contribute to preventing erosion).

The study evaluated the risk from rock falls at a particular location for people driving on roads downslope of an active rock fall, using 3D to simulate rock falls with and without the mitigating effect of the forests. The risk to road users was calculated as being reduced by 91% by the presence of the forests, equating to CHF1,000 per hectare (ha) per year. To replace a forest by hard infrastructure providing the same degree of protection would cost CHF 18,000 – CHF 53,000 per ha. The editors note(3), however, that these values do not take into account the benefits from tourism, wildlife and agro-forestry, which would push these figures even higher.

Other examples include the economic valuation of coastal wetlands for hurricane protection in the USA and Spain, and the calculation of the flood prevention value of the Whangamarino wetlands in New Zealand. Although most of the quantification studies are from the developed world, some are also emerging from developing countries. The International Federation of Red Cross and Red Crescent Societies (IFRC) estimates, for example, that in Vietnam, mangrove restoration is seven times cheaper than maintaining dykes as a mitigation measure against the impacts of tropical cyclones (excluding the value of the secondary benefits to society).

Ecosystems approaches are growing. The Partners for Resilience (PfR), for example, is a collaboration of development and civil society partners that integrates DRR, climate change adaptation, and ecosystems management and restoration. In the Philippines, PfR is working on a project to restore the regulatory role of wetland ecosystems and stabilise hill slopes. CDKN is extracting lessons learned from PfR’s experiences to help shape policies that build community resilience to disasters and climate change.

Ecosystems solutions are, however, not a panacea; the answer lies in a combination of hard infrastructure and green approaches. But ecosystems approaches to DRR provide a number of significant benefits that should not be overlooked. Among other things, they help to avoid maladaptation (when actions to reduce vulnerability to climate change create unintended adverse impacts or increase vulnerability), since the impacts can be assessed continuously.

The evidence of the value of green approaches for risk reduction is stronger for certain ecosystems in relation to specific hazards. More research is needed on others, such as the relationship between vegetation and geomorphology in landslides(4). However, sufficient evidence already exist that ecosystems approaches do work for DRR. As the discussions around the HFA’s successor framework progress, ecosystems-based DRR must be recognised as a significant contributor to our arsenal of risk-reduction options and take a central place in risk management and development practice.


[1] Renaud, FG, Sudmeier-Rieux, K and Estrella, M (eds.) The Role of Ecosystems in Disaster Risk Reduction (2013).

[2] Wehrli, A and Dorren, L, “Protection forests: A key factor in integrated risk management in the Alps” in Renaud, FG, Sudmeier-Rieux, K and Estrella, M (eds.) The Role of Ecosystems in Disaster Risk Reduction (2013).

[3] Renaud, FG, Sudmeier-Rieux, K and Estrella, M, “Opportunities, challenges and future perspectives for ecosystem-based disaster risk reduction” in Renaud, FG, Sudmeier-Rieux, K and Estrella, M (eds.) The Role of Ecosystems in Disaster Risk Reduction (2013).

[4] Papathoma-Koehle, MP and Glade, T “The role of vegetation cover change in landslide hazard and risk” in Renaud, FG, Sudmeier-Rieux, K and Estrella, M (eds.) The Role of Ecosystems in Disaster Risk Reduction (2013).


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