17 March 2017

Hawaii in search of resilience

Hawaii Sea Level Rise Resilience Adaptation Flood Sydney One Climate One Challenge Meza GheungResilience. It looks like the title of a science-fiction movie! It could be one day. For sure it is today a term which is used more and more when talking about the city of the future. What does resilience mean? In biology, the resilience is the capability of an ecosystem or specie to confront a shock and to return to normal after it. As for cities, the definition is quite the same; the shocks being social, economic or… climatic. 


“Beaches are a great public resource here,” Samuel says. Samuel Lemmo is the Administrator of the Hawaiian Office of Conservation and Coastal Lands. “One of my key missions deals with coastal ecosystems, communities, and all issues related to our coastlines. Lots of people live in coastal areas in Hawaii. Erosion is already a massive problem. We also experience large-scale flooding in the low‐lying areas of the State. Climate changes and sea level rise are one of our main concerns.”

Hawaii Sea Level Rise Resilience Adaptation Flood Sydney One Climate One Challenge Meza Gheung
Samuel’s Office is part of the State Department of Land and Natural Resources.
“In 2014, when by law a Hawaii Climate Adaptation Initiative was launched, it was decided that the lead agency would be my office,” Samuel explains. “Quickly I suggested starting a major job: prepare and release a report about sea level rise and Hawaii. We must make our home more resilient! Hawaii is the only island State of the US. Since the beginning of 20th century, the sea level (SLR) has risen by more than 17cm. The report is a vulnerability and adaptation report. It aims at preparing us for future SLR and presenting recommendations to reduce our exposure to the hazards like erosion and flooding.

The Report will include the economic impact on structures, properties or natural resources. Displacing of the communities or relocation of roads will also be assessed. We want to use case studies to better explain the scenarios; we want the recommendations to be presented creatively and tactfully so that people do read them and understand them.”


“Around ten people work on the preparation of the special report, not only from Conservation and Coastal Lands Office but also from the University of Hawaii School of Ocean Earth and Technology,” Samuel says. “Our local research aims to enhancing our assessments of how Hawaii will be impacted in regards to SLR. Our models should be a nice scientific contribution! Indeed they go further than what is usually performed. Traditionally modeling sea level rise has consisted only in projecting to the land the elevation of the sea. We go further. We add three additional parameters: erosion of the coast, passive inundation and annual high wave flooding. In regards to erosion, for instance, we input soil maps and geological data to model erosion effects.” Water spreads differently in contact with sand, volcanic porous rock or hard rock.

On the right, an illustration of passive inundation. Water can come from the ground! Especially if the ground is porous. Florida experiences the phenomenon, they call it sunny day flooding. ©Office of Conservation and Coastal Lands

“We have coral reefs here. They serve as a physical barrier. Well, if the level goes up, energy of the waves will not be stopped anymore, which means we will receive more powerful waves. They will go further landward.” Globally speaking, concerning changes in water-masses and air-masses, it is very complex for scientists to imagine all the induced consequences. Samuel concludes: “With the information, decision makers will be able to better prepare and better response. The report should be available end of this year.”


When we were in Sydney, Australia, we had the chance to meet with Kristin Gabriel who is the Manager of the Resilient Sydney project, for the City of Sydney. She could explain us that “Sydney joined the 100 Resilient Cities initiative in 2015.” The initiative, started by the Rockefeller Foundation, helps cities around the world becoming more resilient. “We identify two categories of disruption. First, chronic stresses refer to constant issues. It can be social cohesion or housing prices for instance. In Sydney, public transportation is an example of permanent concern. Some people are geographically disconnected from the city center because public transportation is not satisfactory there. This deficiency also affects the social cohesion and equality.

Hawaii Sea Level Rise Resilience Adaptation Flood Sydney One Climate One Challenge Meza Gheung
Kristin and Carolina.
Secondly we distinguish the acute shocks which refer to sudden events that threaten a city such as fires, floods or disease outbreaks. In the case of Sydney, extreme heat waves are the number one cause of deaths. Also we consider other climate extremes like storms and floods.” Sydney and Honolulu, Hawaii, are member cities in the 100 Resilient Cities network. We visited or will visit several others during our 2016/2017 trip: Singapore, Melbourne, Wellington, Christchurch and New York City.

A pumping station of Miami Beach. ©City of Miami Beach, Greg Allen/NP

During the last decade, Florida had to deal with more and more floods and storms. Miami has started to adapt: the city builds higher streets, advanced drainage systems and water pumping stations. The city solutions inspire others, not only in order to face SLR, but also to face heavy rainfalls which will be more frequent in lots of regions around the world. In New York City, the Dryline, or BIG U, project consists in constructing a high-water barrier, protecting Manhattan from the rising waters. Year after year, the Big Apple experiences both stronger hurricanes and stronger snow storms. As we said in our previous article, in few decades the climate will have changed. In lots of cities around the world, the adaptation transformation has begun.

Hawaii Sea Level Rise Resilience Adaptation Flood Sydney One Climate One Challenge Meza Gheung
An elevated house, in Houston, Texas.
A nice chart presenting adaptation technologies for coastal areas, according to the Asian Development Bank. ©Asian Development Bank, 2014
Hawaii Sea Level Rise Resilience Adaptation Flood Sydney One Climate One Challenge Meza Gheung
Getting prepared for our meeting with Kristin, at City of Sydney Town Hall!

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