Climate change will increase the risks of devastating floods, especially in low-lying and coastal areas.
Communities that have relocated from high-risk areas show that despite their best defences like seawalls, infrastructure reinforcements, and building codes, they can be overwhelmed and insufficient against continuous threats of flooding, storm surges, and sea-level rise. Moving or relocation will be their best option.
The towns of Grantham in Queensland, Australia, and Oakwood Beach in New York City have opted for managed retreats to avoid devastating floods rather than restoring their community.
Managed retreat is deliberately getting out of the area and out of harm’s way when all adaptation and mitigation will prove unsuccessful. It involves the strategic relocation of assets and people away from high-risk areas.
A study by Miyuki Hino and colleagues evaluated 27 managed retreat cases from 22 countries in three decades. It revealed that 1.3 million people have relocated due to natural hazards like tropical storms, floods, earthquakes, tsunamis, and erosions. However, they predict that more people will be affected by the increased threats of climate change.
The study analyzed these relocations related to climate risks and natural hazards involving two groups– the residents at risk and the government, who initiate relocation and benefit from it.
Other factors are involved regarding the decision to remain or move, such as the government’s political will, societal benefit-cost ratio, and the disaster’s likelihood of occurrence.
Researchers created four quadrants in which they grouped the 27 case studies. The study provides examples of specific case studies under each quadrant.
- The first quadrant, “Mutual Agreement”, is where residents initiate the retreat, and many will benefit from the relocation (high social benefit-cost ratio). Under this circumstance, the retreat will be smooth, residents’ properties will be restored to open space, and the government will spend less on disaster risk reduction and recovery.
- In the second quadrant, “Greater Good,” the government initiates the retreat, but people are unwilling to move. Negotiations are used to resolve agreements. In some cases, the government buys the residents’ properties or elevates their homes.
In the Philippines, after Typhoon Haiyan, the government prevented rebuilding in the hardest-hit area by citing eminent domain. The result is that hundreds of thousands of informal settlers can be stranded without permanent housing for months or years.
- In the third quadrant, “Self Reliance,” the residents push for relocation while the government hesitates to support it because of inadequate societal benefits. This happened in Papua New Guinea’s Carteret Islands. Only 100 out of the intended 1,700 residents have relocated ten years after the residents decided to move due to sea-level rise risk.
- The fourth quadrant, “Hunkered Down,” is when the government initiates retreat without broader societal benefits. A coastal relocation program in the UK initiated a small-scale buy-out of coastal properties at risk of erosion. The program evaluation shows that the benefits did not justify the costs.
Why relocation is difficult for residents
According to Hino, although managed retreat may appear to be a sensible solution, it is controversial and difficult. It is not a low regret nor an easily reversed solution.
Residents moving out are experiencing social and psychological pains from losing cultural heritage and parting from family and their ancestral lands.
For more information, read the entire study: Managed retreat as a response to natural hazard risk
Relocation Experience in the Philippines
Another study from Cornell University published in November 2020 looked at migration in the Philippines as a climate adaptation solution to frequent flooding.
They found that migration is not the main mitigation strategy that Filipinos consider when faced with continuous natural or climatic threats.
Floods are the most common threat faced by Filipinos living in coastal regions. Climate change is causing sea levels to rise and making typhoons stronger and frequent.
Other research finds that there will be a 5 to 10 times increase in the number of Filipinos living under the projected high tide line by 2100.
Garbage and pollution are widespread problems in the Philippines, affecting residents’ water quality and health, especially during flooding. Regular tidal floods and high tides are also causing saltwater intrusion.
Despite these risks, Filipinos would choose to remain in the area due to a “strong sense of place and occupational attachment”. Respondents from the focus group say they would use it to elevate or protect their homes rather than retreat from the area if they had money.
Choosing to say resulted in demanding adaptation measures like taking on extensive infrastructure projects that involve building flood gates and walls to block water, and drainage cleaning, which is all done with assistance from the government and their peers in the community.
Residents would abruptly leave the area in extreme cases where the threat becomes intolerable. Others would leave temporarily but would return as soon as the calamity passed.
In some cases where authorities call for residents to evacuate pending natural disasters, some households will assign a family member to remain in the house for fear of looting.
Respondents say that the lack of resources, capacity, and relocation options are the main reasons they remain in the area.
Read the entire study: Major storm, rising tides, wet feet: Adapting to flood risk in the Philippines
Another study investigated the different resettlement approaches in the Philippines as a climate adaptation option. The study looked at resettlement projects for Metro Manila’s informal settlers.
The most preferred resettlement method is in-city or resettlement within the city than the other off-city option.
The challenge to off-city relocation is to counteract uncontrolled urban sprawl, while the solution to inner-city relocation is to develop innovative, vertical projects.
Researchers point to the relocation of informal settlers as a critical solution to Metro Manila’s congestion compounded by the impacts of Covid-19 and climate change.
Hino, M. (2017, May 1). Adapting to Climate Change Through ‘Managed Retreat’. Acclimatise News. Retrieved from Adapting to climate change through ‘managed retreat’ | Acclimatise – Building climate resilience
Hino, M., Field, C. & Mach, K. Managed retreat as a response to natural hazard risk. Nature Clim Change 7, 364–370 (2017). https://doi.org/10.1038/nclimate3252
DeMint, M. (2021, February, 2). Migration not seen as solution by those in flood zone. Prevention Web. Retrieved from https://www.preventionweb.net/news/view/75860
Hannes Lauer & Mario Delos Reyes & Joern Birkmann, 2021. “Managed Retreat as Adaptation Option: Investigating Different Resettlement Approaches and Their Impacts—Lessons from Metro Manila,” Sustainability, MDPI, Open Access Journal, vol. 13(2), pages 1-24, January.
Williams, L., Arguillas, M., & Arguillas, F. (2020, November). Major storms, rising tides, and wet feet: Adapting to flood risk in the Philippines, International Journal of Disaster Risk Reduction, Volume 50, 2020, 101810, ISSN 2212-4209, https://doi.org/10.1016/j.ijdrr.2020.101810.
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