By 2050 — just 28 years from now — sea level along the coast of Long Island Sound is expected to be 18 inches above today’s level. By 2100 it could be as much as six and a half feet higher than current levels. Extreme weather events caused by climate change, such as strong storms, are also expected to increase in frequency. What all this means for the densely populated coast, which includes some of the state’s largest cities, is that significant changes are on the way.
UConn Department of Plant Science and Landscape Architecture researcher Tao Wu ’21 Ph.D and Extension Educator with the Connecticut Sea Grant program Juliana Barrett recently published a study looking at the changes -or the use of land from the past and the importance of taking factors such as socio-economic development and the dynamic nature of coastal environments into account to make these areas more resilient to change or the climate. Their findings were published in Environmental Management.
This research focused on Connecticut, which has 96 miles of coastline and 24 coastal cities along the Long Island Sound, and the ways that changes in coastal land use are affecting coastal stability. .
Connecticut’s beaches are vulnerable after the rapid development of the 19th and 20th centuries, and because most of the land is less than 20 feet above sea level, the researchers say.
“Based on climate modeling and analogies with glaciological conditions, the global SLR [sea level rise] Projections are more than 50% higher in Long Island Sound than the global average in an intermediate low emission scenario,” said Wu.
Although conveniently located for industry and commerce, the coasts are highly variable and are now challenges for development. Coastal areas are under constant stress from forces such as wind, tides, flooding, sediment deposition, and sea level rise. Development, sprawl, and impervious surfaces add to the problems by increasing the risk of flooding in coastal cities.
The researchers investigated land use and focused on examples from New Haven Harbor, New London Ocean Beach, and Jordan Cove barrier island to study past adaptive measures.
For their work, the researchers used GIS georeferencing of historical maps and satellite images, Digital Elevation Model (DEM) analysis, and analysis of historical documentation.
“GIS methods can help reveal an accurate picture of land use change and land morphologic change in coastal land and its relationship with elevations,” said Wu. “Historical analysis of documentation and analysis of coastal hazards will help our understanding of the adaptive cycle of coastal land use change and the evolution of communities, the changes in disaster response and risk management in the United States and Connecticut and reveals the need to adopt adaptation and resilience. strategies.”
By looking at the history of land-use change, researchers have seen how population growth and development have resulted in an unprecedented level of vulnerability among coastal community in Connecticut.
Wu said that engineering-based solutions such as levees and surge barriers are common adaptation methods adapted for beaches, but they are limited in what they can do.
“Engineered flood mitigation systems can suddenly break down in the face of disturbances that previously could be absorbed and recovered from,” Wu said. “Rigid systems will eventually fail because they cannot take into account uncertainty and try to maintain a perfectly stable situation, especially under the conditions of climate change and the uncertainty that it brings. this.”
In the case of New Haven Harbor, the strict development of the harbor fill form for the construction of the interstate highway system has increased the flood risk in the area.
Wu explained that there are many nature-based solutions and other resilience strategies that help beaches absorb the effects of coastal flooding and storm surges including living beaches, built wetlands, green stormwater management, strategic setbacks, floodplain acquisition, and open space preservation. Conventional engineered solutions are aimed at removing disturbance, but resilient solutions focus on building the ability to absorb and recover from disturbance in coastal areas. In fact, nature-based solutions work with, rather than against nature, as with engineered solutions.
“These methods are especially important for adapting to climate change and natural forces because floodplains and coastlines are dynamic landscapes that are constantly changing and evolving in ways that are not can be accommodated by these engineered structural solutions,” said Wu.
The researchers found evidence of past resilience adaptations, noting how the 1938 New England Hurricane prompted a change in land use for the Ocean Beach community and New London’s downtown waterfront. In addition, New London also implemented green infrastructure measures that helped increase Ocean Beach Park’s ability to absorb storm surges and flood waters to some extent, the researchers said. These steps from the past are now informative.
Faced with rising sea levels and climate change, much of the area surrounding New Haven Harbor is within 100- and 500-year floodplains. The city has now initiated proactive adaptation policies to build resilience.
Considered a “good place” for development in the 1950s, researchers noted that the Jordan Cove barrier island, now underwater, is an extreme case and a good example to consider. long-term dynamics between sea and land in planning and development. .
“The transition from ‘keeping feet dry’ to ‘living with water’ in the Netherlands is an example of resilient thinking,” says Wu. “In Connecticut, we need to help people understand the impacts of climate change such as sea level rise, extreme coastal flooding, and the vulnerability of coastal communities. We also need to incorporate changes -or in our policy making, new development planning, and natural resource management. In a word, we must be strong in mind, then adapt to the changing climate and create sustainable living environment through learning, experimentation, and creativity with the goal of developing new solutions that can cope with our ever-changing environment.”
