Study: Rising Sea Levels Raise Corrosion Concerns


Researchers at the University of Hawaii at Manoa recently unveiled a new study showing that cities with complex networks of buried and partially buried infrastructure may have an increased risk of corrosion and failure of critical systems as sea levels rise.

According to the university, systems such as sewer lines, roadways and building foundations could be at risk of damage due to interactions with shallower and saltier groundwater.

The study was reportedly conducted by Earth scientists at the university and was compiled from research by experts across the globe.

Potential Risks

“While it has been recognized that shallowing groundwater will eventually result in chronic flooding as it surfaces, what’s less known is that it can start causing problems decades beforehand as groundwater interacts with buried infrastructure,” said Shellie Habel, lead author and coastal geologist in the UH Manoa School of Ocean and Earth Science and Technology (SOEST).

“This knowledge gap often results in coastal groundwater changes being fully overlooked in infrastructure planning.”

The research team's aim was reportedly to spread news about these issues and provide guidance from experts on managing them. Habel and co-authors stated that they went over existing research to study the effects on different types of infrastructure.

Additionally, using worldwide elevation data and geospatial data to show the extent of urban development, the team found 1,546 low-lying coastal cities and towns across the globe that are likely experiencing these impacts. Approximately 1.42 billion people live in these areas, the university says.

“The IPCC 6th Assessment Report tells us that sea-level rise is an unstoppable and irreversible reality for centuries to millennia,” said Chip Fletcher, study co-author, interim dean of SOEST, and director of the UH Manoa Climate Resilience Collaborative (CRC).

“Now is the time to prepare for the challenges posed by this problem by redesigning our communities for greater resilience and social equity.”

Additionally, before the visible effects of surface flooding appear, the sea-level rise will reportedly push up the water table and shift salty water landward. The team explains that, as this happens, the subsurface environment could get more corrosive to critical underground infrastructure networks.

Researchers at the university say that buried drainage and sewage lines can become compromised and cause the spread of urban contamination, while building foundations can be weakened by this process.

Extensive research from CRC has reportedly proven that critical infrastructure around the world, including drainage and basements, is likely experiencing flooding from rising groundwater levels.

“The damage caused by sea level rise-influenced coastal groundwater is often concealed and not immediately perceptible,” said Habel, who is based at CRC and Hawaii Sea Grant in SOEST. “As a result, it tends to be overlooked in infrastructure management and planning efforts.”

Additionally, the authors noted the importance of research efforts that could contribute to more informed adaptation strategies.

“Being aware of these hidden impacts of sea-level rise is of significant importance for the State of Hawaii due to the concentration of communities situated along low-lying coastal zones where groundwater is generally very shallow,” said Habel.

The university states that CRC works with partners across the nation and infrastructure managers in Hawaii to get accurate assessments of how vital infrastructure, like pipe networks, roadways and buildings, is impacted.

The team believes that understanding the impacts and risks associated with sea level rise-influenced coastal groundwater can allow for the creation of more effective management and adaptation.

Similar Research

In September of last year, a team of researchers was reportedly working to advance efforts to enhance infrastructure information-sharing by building an inventory of stormwater control measures (SCMs) operating in 23 United States cities.

The report stated that researchers from six universities, as well as the Water Research Foundation (Alexandria, Virginia) and the U.S. Geological Survey, were reportedly attempting to identify patterns among the types of SCMs cities pursue and the various physical, climatic, socioeconomic and regulatory factors driving those choices.

Working closely alongside stormwater professionals in these cities with sufficient information about their SCM networks, the researchers reportedly compared the frequency and density of different SCM classes against a series of other city characteristics.

The characteristics reportedly included the city’s average slope and proximity to the water table, as well as its typical climate, its population density, whether it contained combined or separate collection systems and if it was subject to a consent decree or other atypical regulatory requirements.

According to the report, through drawing clearer connections among the types of common constraints that might make one type of SCM more cost-effective than another, the study reportedly sought to help cities of all sizes find out what makes a particular piece of infrastructure site specific.

Using statistical methods, researchers teased out multiple patterns that detail which city characteristics hold the most sway over the types of SCMs they pursue.

Such physical considerations as the amount of impervious space in each city, its average slope, its distance to the water table and its use of groundwater were reportedly the strongest determinants of the type of SCMs cities built.

The report stated that as an example, cities that were not limited by a shallow water table generally chose infiltrators over basins, strips and swales, or filters, but infiltrators were less common in lower-elevation cities.

The infiltrators class included SCMs like infiltration basins and vaults, trenches, dry wells and permeable pavers. In contrast, such climatic variables as average precipitation and temperatures, aridity and water-vapor pressures reportedly had little or no correlation with any particular type of SCM.

The researchers stated that filters were also implemented more often in cities with a greater percentage of regulated waterways classified as impaired, as well as those that struggle with chronic combined sewer overflows.

This finding was expected to help show that U.S. cities regard filters as the most reliable or cost-effective route to reach regulatory targets related to water quality. Basins—such as wetlands, cisterns and forebays—reportedly tended to be less common in cities with stricter regulatory obligations.

Results also noted noticeable differences in the scale and diversity of urban SCM networks. For example, Los Angeles was found to maintain the lowest density of SCMs, with as few SCMs as 0.46/sq. kilometers (0.74/sq. miles) of impervious area, indicating a preference toward larger, regional interventions.


Tagged categories: Asia Pacific; Colleges and Universities; Corrosion; Corrosion protection; EMEA (Europe, Middle East and Africa); Environmental Control; Environmental Controls; Environmental Protection; Exposure conditions; Health & Safety; Health and safety; Infrastructure; Infrastructure; Latin America; NA; North America; Pipes; Program/Project Management; Research and development; Roads/Highways; Safety; Seacoast exposure; Sewer systems; Stormwater; water damage; Weathering

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