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What El Niño has taught us about infrastructure resilience

Irene Portabales González's picture
Also available in: Español
Photo: Ministerio de Defensa del Perú/Flickr
The rains in northern Peru have been 10 times stronger than usual this year, leading to floods, landslides and a declaration of a state of emergency in 10 regions in the country. Together with the human and economic toll, these downpours have inflicted tremendous damage to transport infrastructure with added and serious consequences on people’s lives.

These heavy rains are blamed on El Niño, a natural phenomenon characterized by an unusual warming of the sea surface temperature in the central and eastern equatorial Pacific Ocean. This phenomenon occurs every two to seven years, and lasts about 18 months at a time. El Niño significantly disrupts precipitation and wind patterns, giving rise to extreme weather events around the planet.

In Peru, this translates into rising temperatures along the north coast and intense rainfall, typically shortly before Christmas. That’s also when “huaicos” appear. “Huaico,” a word that comes from the Quechua language (wayq’u), refers to the enormous masses of mud and rocks carried by torrential rains from the Andes into rivers, causing them to overflow. These mudslides result from a combination of several natural factors including heavy rains, steep slopes, scarce vegetation, to name a few. But human factors also come into play and exacerbate their impact. That includes, in particular, the construction of human settlements in flood-prone basins or the absence of a comprehensive approach to disaster risk management.

This year’s floods are said to be comparable to those caused by El Niño in 1997-1998, one of the largest natural disasters in recent history, which claimed the lives of 374 people and caused US$1.2 billion worth of damages (data provided by the Peruvian National Institute of Civil Defense).

Climate and disaster risk in transport: No data? No problem!

Frederico Pedroso's picture
Development professionals often complain about the absence of good-quality data in disaster-prone areas, which limits their ability to inform projects through quantitative models and detailed analysis.
 
Technological progress, however, is quickly creating new ways for governments and development agencies to overcome data scarcity. In Belize, the World Bank has partnered with the government to develop an innovative approach and inform climate-resilient road investments through the combination of creativity, on-the-ground experience, and strategic data collection.
 
Underdeveloped infrastructure, particularly in the transport sector, is a key constraint to disaster risk mitigation and economic growth in Belize. The road network is particularly vulnerable due to the lack of redundancy and exposure to natural hazards (mostly flooding). In the absence of alternative routes, any weather-related road closure can cut access and severely disrupt economic and social movement.
 
In 2012, the government made climate resilience one of their key policy priorities, and enlisted the World Bank’s help in developing a program to reduce climate vulnerability, with a specific focus on the road network. The institution answered the call and assembled a team of experts that brought a wide range of expertise, along with experience from other climate resilience interventions throughout the Caribbean. The program was supported by Africa, Caribbean and Pacific (ACP) European Union funds, managed by the Global Facility for Disaster Reduction and Recovery (GFDRR).
 
Our strategy to address data scarcity in Belize involves three successive, closely related steps.

Preparing transport for an uncertain climate future: I don’t have a crystal ball, but I have a computer

Julie Rozenberg's picture
Photo: Alex Wynter/Flickr
In 2015, severe floods washed away a series of bridges in Mozambique’s Nampula province, leaving several small villages completely isolated. Breslau, a local engineer and one of our counterparts, knew that rebuilding those bridges would take months. Breslau took his motorbike and drove the length of the river to look for other roads, trails, or paths to help the villagers avoid months of isolation. He eventually found an old earth path that was quickly cleaned up and restored… After a few days, the villagers had an alternative to the destroyed bridge, reconnecting them to the rest of the network and the country.

What happened in the Nampula province perfectly illustrates how a single weather event can quickly paralyze transport connections, bringing communities and economies to a screeching halt. There are many more examples of this phenomenon, which affects both developing and developed countries. On March 30th, a section of the I-85 interstate collapsed in Atlanta, causing schools to close and forcing many people to work from home. In Peru, food prices increase in Lima when the carretera central is disrupted by landslides because agricultural products can’t be brought to market.

How can we help countries improve the resilience of their transport networks in a context of scarce resources and rising climate uncertainty?

Are roads and highways the Achilles Heel of Brazil?

Frederico Pedroso's picture
Also available in: Português
Photo: Ricardo Giaviti/Flickr
Over the past three years and a half, our team has been working on a transport project with the state of São Paulo in Brazil. The project involves a lot of traveling, including frequent commutes between the World Bank office in Brasilia and the State Department of Transport in São Paulo (DER-SP)—a journey that is estimated to take 2 hours and 40 minutes. This includes the time to drive from the World Bank office to Brasilia Airport, flight time, and commuting from São Paulo’s Congonhas Airport to the State Department of Transport.
 
Let’s say that, on a typical Wednesday, the team needs to attend a meeting in São Paulo. To ensure we can make it on time, we plan our day carefully, book our flights and define the right time to leave the office in Brasilia. With a plan in place, we leave the office at 10:00 am and head to Brasilia Airport. The first leg of the trip takes 35 minutes and we manage to arrive early for our 11:00 am flight, which, unfortunately, is delayed by 20 minutes. We land in São Paulo, quickly get out of the terminal, and manage to hop on a taxi at 1:20pm… not bad! We are now on the last leg of our journey, a mere 14-kilometer drive between Congonhas Airport and the meeting place, which is supposed to take only 20 minutes. However, there is a short thunderstorm that floods the city and closes off key streets. This single event leads to complete traffic chaos along the way, and our planned 20-minute transfer from the airport turns into a 1-hour-and-15-minute ordeal. These traffic disruptions have a serious impact on our meeting as well, as some Department of Transport staff cannot join and some items of the agenda cannot be discussed.
 
This incident may seem anecdotal, but it is a good illustration of our extreme dependency on transport systems and the weaknesses associated with it. Because transport is so critical to our social and economic lives, it is extremely important to understand, anticipate, and minimize the different types of risks that may impact transport systems.

The “plastic bridge”: a low-cost, high-impact solution to address climate risk

Oliver Whalley's picture
Also available in: Français
Photo: Anthony Doudt/Flickr
Bridges are critical links in the transport network. In their position across waterways, they are exposed to the full effects of flooding and landslides, and are often the first pieces of infrastructure to be damaged in the event of a disaster. They also typically take weeks or months to repair.  Besides causing expensive damage to the infrastructure itself, disruptions in connectivity also have a much broader impact on economic productivity and people’s ability to access essential services. As many places are expected to witness more intense and frequent rainfall as a result of climate change, the risk to bridges will only worsen: more rainfall will lead to bigger river flows and more damage to bridges, especially those designed to handle smaller storms.

At each end of a bridges is a structure which supports the weight of the deck. These are known as abutments, and they are often the first part of the bridge to fail. Blockage of the main channel by debris can cause water to look for the path of least resistance around the sides of the bridges, thus placing the abutments at risk.

Traditional bridge construction requires the installation of piles for the foundations of abutments—a lengthy and expensive process that involves specialist materials, skills and equipment.

But there is another promising solution: Geosynthetic Reinforced Soil (GRS) abutments. These allow for rapid and resilient construction of bridge abutments using locally available materials, without specialized equipment. With GRS, bridges can be constructed in as little as five days (Von Handorf, 2013) and at a cost 30-50% lower than traditional approaches (Tonkin and Taylor, 2016) .

GRS abutments are based on ‘geogrids,’ a high density mesh made out of polyethylene (plastic). Layers of soil and geogrid are combined to create a solid foundation for the bridge deck. Construction can be completed with basic earthmoving and compaction equipment, and a range of local fill materials can be used with guidance from geotechnical specialists.

Climate change is forcing us to reinvent rural transport for the better

Ashok Kumar's picture
Photo: Ravisankar Pandian/Flickr
India is in the midst of implementing PMGSY, a $35-billion national level Rural Road Program designed to provide basic road access to rural communities. The World Bank is supporting PMGSY through a series of lending operations ($1.8 billion in Bank funding) and significant knowledge support. A key element of the Bank’s support has been to integrate a “climate and green growth lens” into these efforts in cost-effective ways.

How is “green growth” benefiting India? One important dimension of that effort has been  the use of environmentally optimized road designs, which has resulted in quality infrastructure using local and marginal materials, providing both economic and environmental benefits. Where available, sand deposits accumulated from frequent floods, industrial by-products, and certain types of plastic, mining, and construction waste have been used to good effect. Designs that use such materials have been about 25% cheaper to build, on average, than those requiring commonly used rock aggregates. The environmental benefits of using the above materials, in terms of addressing the big disposal problem of such materials and reducing the consumption of scarce natural stone aggregates, are as significant as the cost savings.

A second “green growth” dimension has been focusing investments on the “core” network, i.e. the network India needs to develop in order to provide access to all villages. Relative to a total rural road network of about 3.3 million kilometers, the core network that falls under PMGSY stretches over only 1.1 million kilometers. Prioritizing construction and maintenance on those critical road links will bring down costs as well as the associated carbon footprint.