Resilient cities

Ultimate resilience: Floating Oceanix City – picture Bjarke Ingels Group (public domain)

Building dykes as flood protection is one of the oldest forms of resilience. However, people only started building dykes after their houses, roads and crops had been flooded several times and they had managed each time to recover from the damage. Later, the dykes broke and they were reinforced. This brings us to the core of the concept of resilience: Building capacity within individuals, communities, institutions, businesses, and systems to survive, adapt, and grow no matter what kinds of chronic stresses and acute shocks they experience.


Resilient Cities is the second of a series of short essays on how we can make our cities more humane. That means finding a balance between sustainability, social justice and quality of life. This requires far-reaching choices. Once these choices have been made, it goes without saying that we use smart technologies to realize them.

The concept of resilience

Resilience is an attitude of individuals and also a behavioral pattern of a group of people, for instance inhabitants of a city. The 100 Resilient Cities-movement (100RC) distinguishes seven qualities that together characterize resilience.

Qualities of resilience – 100RC

The use of the term resilient city has been promoted by international organizations and associations of cities to improve the ability of cities to handle hazards such as hurricanes Katarina in the New Orleans region (2005) and Sandy along the east coast of North America (2012).

In subsequent years, the concept hazard has been expanded to include external pressures in general, varying from climate change, environmental degradation to poverty. That is why the 100RC-movement distinguishes between chronic stresses and acute shocks.

  characteristics examples
Chronic stress Repeating events that weaken the fabric of a city on a daily or cyclical basis. High unemployment, inefficient public transportation system, endemic violence and chronic food and water shortages.
Acute shock Sudden events that disrupt the life in a city. Earthquakes, floods, disease outbreaks, airplane crashes and terrorist attacks

Becoming resilient at city level refers to policies that deal with all these types of hazards. These policies include:

  • Precautionary measures based on the recognition and anticipation of imminent threats.
  • Coping strategies, including directs actions to limit damage, to help victims and repair the damage.
  • Prevent risks or mitigate their impact.

Below, I will discuss each of these aspects

Precautionary measures
The most difficult problem in anticipating hazards is knowing which hazard has to be anticipated. This is difficult, given the long list of chronic stresses and acute shocks that can hit a city. Although cities can make an overview of possible hazards and their impact, it is better to prepare in a more generic way, for example by making evacuation plans or assure that communication channels remain available.

Environmental monitoring
If there are several potential threats, a regional environmental monitoring system is useful. In Moscow, such a system measures the quality of air, water and soil, noise level, and dangerous geo-ecological processes.

The measurement infrastructure comprises 56 automated stations that monitor air quality; 66 approved control lines for surface water monitoring, 130 locations for soil research and 13 locations to observe landslide processes.

Private developers have designed mobile applications (Plume Air Report, Moscow Air, Eco monitor, Moscow Air Lite) for online and real-time use of this data.

In areas where flooding is a recurring phenomenon, citizens and government agencies can anticipate the threat by installing early warning systems, preparing emergency services, availability of scenarios for the evacuation of the elderly and the sick, assigning places for temporarily housing, collecting tents, organizing access to food, drinking water and to medical care. The faster and more accurate the prediction is, the better the preparations can be.

One Concern, a benefit corporation, started in 2018 with the prediction of floods through artificial intelligence. The company had previously developed successful procedures for earthquake forecasting. The video below gives an impression of these advanced and accurate systems for predicting hazards.

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Prediction of floods by artificial intelligence
Flood Concern makes map-based visualizations of places where floods can hit hardest, up to five days before an approaching storm. It involves simulations in the form of time-lapses of how the water will rise, at what speed and in which direction.  These maps also indicate which parts of the infrastructure will get flooded or washed away, and mitigation efforts – from sand backs to opening locks – will turn out. These data allow emergency teams to determine which roads are still accessible, and to plan evacuation routes accordingly.
(Direction of flooding water – Figure by Flood Concern (public domain))

In addition to prediction of hazards, cities also need real-time information about inundated areas. It is useful to ask citizens to support the collection of data for various reasons: The information will come from all parts of the city and in the meantime, they are prepared for a possible evacuation.

Mapping the extension of flooding with crowdsourcing
Greater Jakarta experiences regular flooding. is a tool that combines data from sensors with reports from citizens via social media such as Twitter. The maps made with this data in real time provide the government and residents the best available information about the flood.

The system is programmed to react when someone in Jakarta tweets the word “banjir” (flood) and tags @PetaJkt. The system automatically replies and asks to confirm the tweet with geotagged photos. All incoming reports are combined to build an up-to-the-minute, online flood map. This innovative tool is powered by CogniCity.
(Flooding in Jakarta (print screen tweet) – picture by PetaBencana (public domain))

Emergency plans must not focus only on the most probable disasters, but on all conceivable ones. Making a list of potential threats is not that difficult: Plane crashes, terrorists who blow up a dam or shoot visitors during a football match, previously unknown massive and violent protests, outbreak of a hitherto unknown deadly disease, an attack by a foreign power or, if you want, aliens, et cetera.

It is impossible to make separate plans for all these threats. The preparation must take place on a more abstract level. For example, how to act if roads are impassable, a large number of people have died, there is no electricity, water and gas, an evacuation must take place within a few hours, et cetera.

Agreements must also be made in advance about outside assistance and on which means of communication a permanent appeal can be made. Together with aid organizations, the government must be prepared to build and equip emergency hospitals within a few days.

At last, there must be well-considered ideas about the coordination of the operation, even if the most eligible people are dead or taken hostage. in the US, not only communal authorities, but also insurance companies prepare their customers in areas that are sensitive for hazards.

Restoring communication in devasted areas
Last year, IBM won Fast Company’s World Changing Company of the Year award for various projects that use technological know-how to save lives.

One is an ingenious solution to restore internet-connections in disaster-stricken areas, by dropping a large number of small hexagonal rubber balls into a disaster area: They are watertight, can float and can function wherever they end up. Each ball has a small and durable mini Wi-Fi relay. By working together, they create an ad hoc mobile network.
(Floating Wi-Fi relay – picture IMB)

Coping with disaster
As soon as local authorities become aware of an imminent disaster, the earlier prepared scenarios are set a-going. In case of flooding or hurricanes, these measures vary from removing loose objects to evacuation of citizens. Stocks of necessary materials as wooden shelves to protect windows, sand backs, pumps and inflatable boats are transported to the places where the will be needed most. In the event of a forced evacuation of civilians, the places of destination have to be equipped with water tanks and food.

One of the most dramatic cases to discuss the concept of resilience and its partial failure is the massive earthquake that destroyed the whole of Haiti on January 12, 2010, claiming 316,000 lives, injured another 300.000 people and displaced more than 1.5 million people. The earthquake was just the beginning:  In the following years other destructive natural disasters caused thousands of new deaths, engraved famine and a deadly cholera epidemic, destroying the ongoing efforts to rebuild the country. So far, almost nine years later, millions of Haitians still need humanitarian assistance and many still live in camps without proper sanitation and drinking water. In the meantime, the international community has raised € 8 billion in aid. What it was used for is unclear, in spite of a large number of helping hands. It seems that the reconstruction of the land is mainly due to the resilience of the residents, who started to rebuild their primitive huts time and again by using the remains of their previous emergency shelter. The government infrastructure of the country was completely destroyed by the dictatorial regimes of father and son Duvalier and led, among many other things, to the depart of most residents with some education.

The Haiti-case shows the combined effect of a devasting earthquake, the total unpreparedness of the government and the population and, unfortunately, failure of the relief effort by the global community.

Earthquakes are probably the most devasting natural hazards. Their power can ruin the entire infrastructure, from command centers to stock of repair materials. This underlines the need for redundancy when taking precautions. At the same time, it emphasizes the need for resilience as a part of the social capital of the population concerned. Social capital makes self-organization, the willingness to cooperate and trust.

The Extreme Weather-app
A freely available application alerts citizens and government about current and future weather conditions at their current location. It is also capable of detecting and predicting sandstorms, which pose a major challenge in the Middle East. The app is powered by a series of algorithms using real-time satellite data and weather forecasting models. One of these models is the chemistry transport model CHIMERE an open source model for dust and air quality forecasting and simulation that allows researchers to enter weather and land surface variables such as wind speed, humidity and soil composition, in order to produce forecasts of dust and other aerosol/gaseous pollutant species including ozone.
(Dust storm in UAE- picture OECD)

Preventing disaster
The ultimate challenge for a resilient policy is to prevent or reduce the effects of natural or man-made hazards. After the flooding of parts of the Netherlands in February 1953, the Delta Plan was designed to provide protection against the worst possible storms. Everyone believed that when the plan was implemented, the Netherlands would be safe for the coming centuries. This idea does not fit into the perspective of resilience. The Delta Plan was based on resisting storms that had destroyed parts of the country in 1953 or even stronger. Resilience requires going beyond known threats. These are not only severe storms, but also an increase in the level of the sea and a decrease in the level of land and groundwater. Not to mention the dehydration of the soil and the damage to the piles on which all houses and buildings are build. Against this background the idea of ​​floating cities arose.

In earthquake zones, new buildings are generally resistant to earthquakes. But this mainly concerns the high-rise buildings in the business districts and not the places where the majority of people live, let alone the slums of the billion inhabitants of slums.

Resilience in practice

The Haiti case proves that a resilient population is not enough to cope with the damage caused by natural and man-made hazards. Fortunately, cities and their inhabitants in other parts of the world were more successful. The examples below show that resilience requires an interaction between technological solutions and investments in social capital.

New Orleans
In 2005, Hurricane Katrina destroyed New Orleans. 80% of the city was flooded and the disaster cost nearly 1,000 lives. The damage amounted to $ 135 billion. However, the impact of the storm was exacerbated by institutional racism, outdated infrastructure and poor economic conditions.

Surrounded by water on four sides, the city has realized that water must be regarded as a permanent feature of the urban landscape. Once the recovery began, not only were flood risk management systems developed, but the resilience of residents was considered too: An example is the Gentilly Resilience District, in which all residential areas have water management systems with the objective of reducing flood risks, preventing subsidence and promoting water retention, strengthening coastal protection and increasing the capability of the population to cope.

New York
In 2012, Hurricane Sandy caused 160 deaths and US$ 71 billions of damage along the US east coast, leaving tens of thousands homeless people across the region. Over 300,000 housing units were damaged, inhabited primarily by economically disadvantaged households. New York City has developed a comprehensive plan to strengthen isolated and underserved communities and reduce their vulnerability in the face of future challenges. It includes the reinforcement of homes, a raised shoreline, improvements to public housing, transport and community centers.

The recovery from hurricane Sandy brought resilience to the heart of the city administration and resulted in an even much larger project, saving New York from floods to be caused by global warming. New York City Mayor Bill de Blasio recently announced a $10 billion coastal resilience project, designed to protect Lower Manhattan from flooding. Without such a plan in 2050, 37% of properties in Lower Manhattan are at risk from flood, up to 50% in 2100, when 20% of streets will be exposed to daily flooding.

Flooding Manhattan 2050 – 2100 – Picture City of New York, Mayor’s office (public domain)

Medellin was the world capital of crime last century. Nevertheless, the population increased rapidly, which coincided with other chronic tensions, such as poverty, poor planning and inadequate infrastructure. The most vulnerable residents built illegal houses on slopes in the city that are sensitive to landslides. These concentrations of the poor and unemployed were far removed from the commercial center in the valley and the services of the government.

Then the miracle happened: Since 1991 the number of murders has fallen by 95% and since the beginning of the 21st century the percentage of poor dropped by 22.5%. Medellín achieved this through cooperation between all groups within and outside the city council. The city stopped forced relocations of residents from slums to high-rise buildings. Instead, she started investing in upgrading existing residential areas and especially improving their accessibility. To this end, an innovative public transport system was developed that not only reduced travel time and traffic congestion, but also promoted social cohesion and employment.

Disaster Risk Assessment Made Simple (HARD)
Tool provides means to perform a simplified disaster risk assessment to prioritize actions elaborate and implement a disaster risk management plan, including emergency procedures and awareness campaigns.

It enables to enhance cooperation with government and provides a platform for citizens to actively collaborate. The tool is composed by a web-based platform, where information can be entered and monitored, and a mobile app, where interaction with citizens

The software has three main components:

  • Map of the city including geographic, land use, demographic, infrastructure and buildings.
  • Mapping and evaluation of disaster risks, considering exposure and vulnerability aspects.
  • Financial data on historic, current and future disaster events, entailing CAPEX and OPEX.

(Illustration: Conceptual-framework-for-disaster-risk-assessment by Mariana de Brito)

The booming resilience movement

As mentioned, the realization of the need to integrate resilience in urban planning grew rapidly in the second decade of the 21th century. It was called ‘the design imperative’ of the 21th century. Design used to be based on a set of defined use cases, which provided the required features, materials, capacity, and strength, which is called the ‘happy path’. However, reality is chaotic and messy and things often go otherwise or wrong.

Designing for resilience is more than helping people prepare for disasters; it is a fundamental change in thinking about (urban) strategy and collaboration. That is why building a more resilient world begins with the broadening the design process and take account for the ‘unhappy paths’. Cities need to look holistically at their capacities and risks, instead continuing a silo-ed approach with different teams designing disaster recovery plans, separately investigating sustainability issues, livelihood and wellbeing, land-use and infrastructure.

The resilience movement boosted after the Rockefeller Foundation invested $100 million in the 100 Resilient Cities Challenge in 2014 to transform public institutions, functions, and operations in the participating cities. To achieve this goal, an autonomous organization 100RC was created. The organization has selected three cohorts of approximately 30–35 cities, announced in December 2013, December 2014, and May 2016. Member cities are enabled to appoint a ‘chief resilience officer’ to act as an internal champion and to lead the process of developing a resilience strategy. In addition, 100RC facilitated ample contacts between the growing number of resilience officers, senior officers and mayors, because resilience activities include institutional change in government operations, such as de-siloing efforts between emergency management and community development entities.

A comprehensive midterm review of the project was recently completed by the independent Urban Institute, as a prelude to the summative evaluation in 2022.  This overall positive evaluation states that 100RC has been influential as a provider of resilience assistance and an advocate to others for resilience investments. This is due to the size of the Foundation’s resources used (so far: $ 164 million), the size of the interventions that already have taken place (2600 projects, worth $ 3,35 billion) and the possibility of summative learning for the scientific and professional field.

In total surprise, the Rockefeller Foundation announced in 2019, April 1, that the program would be dissolved, without any explanation. A challenge for its partner’s resilience?

Strategy development

The development of a City Resilience Strategy is mandatary for all 100RC-partners. During a six- to nine-month period, cities map out the challenges they face and develop a holistic strategy to address them.

The strategy-building process was developed and validated by Arup. A short video gives a general overview of the procedure.

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The process starts with a systematic inventory of stronger and weaker points of a given city from a resilience perspective, summarized in a resilience index. Part of this process is the collection of data and the filling the cells of the so-called City Resilience Framework. The data is ‘weighted’ by using the seven ‘resilience qualities’ already mentioned in the introduction of this article. This part of the process is a joint effort, involving hundreds of citizens and other stakeholders. The next stage is the formulation of resilience goals.

City resilience framework – Picture 100RC

Rotterdam – for instance – has formulated seven resilience goals, which are realized with 60 projects.

The seven resilience goals of Rotterdam are:

  1. Rotterdam: a balanced society
  2. World Port City built on clean and reliable energy
  3. Rotterdam Cyber Port City
  4. Climate Adaptive city to a new level
  5. Infrastructure ready for the 21st century
  6. Rotterdam network – Truly our city
  7. Anchoring resilience in the city

Almost all plans that I have scrutinized have similar chapters, resulting in dozens of actions and intentions for further study too. Most strategies refer to pre-existing planning documents, sometimes with the suggesting to add the perspective of resilience.

100 RC has allowed Arup to make available all project tools, formats and other project aids free of charge in order to enable non-100RC cities to make their own resilience strategy.

Tools and formats to create a resilience strategy
Civil servants and politicians have a large number of tools at their disposal to strengthen the resilience of their city. The following sources produces by Arup are very informative and available for free thanks to the Rockefeller Foundation.

Reading the resilience strategies of towns all over the word is encouraging. They are written from a citizen-in-the-center perspective and all plans pay substantial attention to the relation between man-made hazards, poverty and inequality.

Nearly all plans propose actions in the following fields:

  • Improving of housing
  • Creation of jobs, viable incomes and basic services.
  • Strengthening of community ties
  • Improving communication between administration and citizens
  • Fueling pride among citizens of their city
  • Protection again global warming, and use of carbon-free energy.
  • Protection against natural hazards

I was surprised that all strategies focus primarily on man-made hazards and their prevention in particular. I expected a more comprehensive elaboration of anticipation, coping with, mitigation and prevention of all kind of hazards. The emphasis seems to be reversed in ten years. I realize that to prevent or to mitigate the impact of natural hazards is requiring towering investments at a national level. Take the Dutch Delta plan as example. But a major role for anticipation and coping with natural hazards in the local resilience strategy is mandatory and this aspect is undervalued.

The twelve earlier mentioned aspects of resilience show significant overlap with recurrent themes in city-planning documents. Therefore, the integration of the resilience perspective in these documents is a next step. Nevertheless, developing resilience strategies was an extremely valuable endeavor, as many citizens became involved and as a result contributed to striking citizen-centered perspective. This is in contrast to many other strategic plans that are primarily based on (economic) growth.

Resilience in the humane city

Reconciling the concepts of resilience and humanity is not difficult. The concept of resilience is rooted in a deep desire to alleviate the pain of the countless victims of chronic stress and acute shocks and to protect people from future suffering. All resilience strategies developed by the 100RC-cities are admirable steps into this direction. It is painful to see how many of these cities lack the resources to prevent even part of their intentions, which temps them sometimes into symbolic policies. Athens, for example, followed an excellent participatory approach during the development of its strategy but any desirable action struggles with the overall poverty of the city and its inhabitants. The same applies to many cities in developing countries and – in contradiction with the wealth of a small part of its citizens – for cities in the US.

Most acute chocks and chronic stresses and the failure to anticipate, cope, mitigate, or prevent are not rooted in nature, divine destiny or fate, but in the unequal distribution of resources and the abuse of power – corruption included – worldwide.

To the extent that hazards are natural, many could have been prevented or at least mitigated by a better infrastructure, or even by deploying better technologies for predicting them. And when they strike, they hit the poor population most. In the case of man-made hazards, they are often associated with poverty and inequality. The Medellin-case is a hopeful example that years of determined policy can reverse the cycle of crime and poverty.

It is helpful to distinguish between resilience as a characteristic of (political) entities, such as towns and as a characteristic of individual people. On the first level, resilience includes policies directed at the mitigation and prevention of chronic stresses and acute shocks and creation strategies to achieve this. The most dominant characteristic of resilience on the second level is the ability of individuals and groups to live with and recover from chronic stress and acute shocks through self-organized and collaborate actions (social capital). Where first-level resilience failed in Haiti, ordinary people managed to survive because of this second level.

Finally, I summarize the essence of a humane approach to resilience in our cities, considering the relationship between urban policy, wealth and health.

Actions for a humane approach to resilience in cities

  1. Most global cities face the challenge of integrating resilience into their already overloaded tasks. At the same time, they are chronically under-resourced. Their share in the national budget must grow significantly, which ultimately means that the national income must be distributed differently.
  2. At present, global warming is broadly recognized as a one of the most threatening chronic stresses. The energy transition is considered as the adequate answer. That is only partly the case: Unfortunately, even a complete cessation of greenhouse gas emissions in 2050 will not stop global warming, the rising of the sea-level, the growing number of storms and showers, and ongoing desertification elsewhere. After all, the atmosphere is saturated with CO2 and other greenhouse gasses. These and other hazards will result in an until now unknown migration and resettling movements in this and the next century.
  3. The perspective of long-term resilience will radically change urban planning. Regardless of the need for profound improvements in the physical design of towns in the next decade, the survival of many cities in itself is at stake due to the rise in sea level and has to be taken into consideration. However, long-term resilience thinking still is in its infancy.
  4. Cities must, in cooperation with national authorities invest more in advanced forecasting technologies of (natural) disasters, using sensing and artificial intelligence. All strategies for reducing the consequences of disasters require better knowledge of the occurrence, intensity, behavior and impact of these hazards and appropriate technologies are available.
  5. Contingency plans have to be developed in collaboration with (representatives of) citizens. Citizens should be allocated specific roles, if these plans have to be executed. Resilience also implies the preparation of territory for temporary housing, mapping out provisional external communication channels and preparing strategies for (temporary) reconstruction of destroyed parts of the city.
  6. A significant relation exists between man-made hazards and poverty and its side effects such as insufficient housing, illness, lack of education, unemployment, gang membership and criminality. However, this relation is neglected often. For each city, the first, albeit major steps towards resilience are increasing income, providing decent housing and work and an attractive living environment.
  7. Secularization and individualization and more in general loss of social capital are characteristics of contemporary city life. This applies to all social groups and is accompanied by growing distrust, less participation in community life and lack of willingness to help. All these circumstances weaken resilience. Cities can reverse this process by encouraging and supporting ‘commoning’ initiatives at neighborhood level and strengthening the esthetic and cultural identity of the town, and in particular by enabling participation and self-government of citizens at all levels.
  8. Resilience requires fundamental choices. Maybe higher dikes, certainly advanced techniques for predicting disasters, but above all a higher income for the lowest paid.



*) This article was brought to you by Professor Herman van den Bosch, Professor at Open University of The Netherlands.