Protecting New Zealand’s coasts and communities

As the world grapples with the concerning effects of rising sea levels, Aotearoa New Zealand is taking proactive steps to address the unique vulnerabilities of its coastal areas and protect the wellbeing of its communities.

Sea level rise is being fuelled by melting ice in polar areas and in alpine glaciers, which is combined with expansion of the ocean caused by a temperature increase. While the sea level is rising around Aotearoa New Zealand, whether coastal communities are at risk depends on if the land is rising or falling in their area.

Aotearoa New Zealand is tectonically active, and researchers have recently mapped vertical movements along our coasts, showing some areas are experiencing upward shifts (making relative sea level rise smaller) while others are sinking (causing relative sea level rise to be greater).

Many organisations and researchers around the world are working together to get a clear understanding of the global impact; however, because of Aotearoa New Zealand’s unique coastline and vertical-land movements, an individualised approach is needed.

Our Changing Coasts is a five-year MBIE funded programme bringing together world leading researchers to help forecast sea levels over the next 100 years, and how our coastal landscapes will change. This programme, led by Professor Richard Levy from Victoria University of Wellington, builds on NZ SeaRise, which produced sea level projections to include state-of-the-art global climate data and estimates of local vertical land movements around Aotearoa New Zealand.

“These projections offer a big step forward in our efforts to understand the pace and magnitude of future sea level change at a local level, but the projections don’t include detailed information regarding the local impacts of sea level change on our coastal environmental and communities. These impacts are a focus of Our Changing Coast,” says Professor Levy.

The team have partnered with TAIAO and will be using machine learning and detailed process-based models to better understand where our most vulnerable coastlines are. Professor Karin Bryan, who is leading this initiative for TAIAO, is very excited to support this programme.

“This is the type of work that TAIAO is all about” she says.

“The vertical movements, unique coastlines, and weather events that are out of our control make it very difficult for us to understand what will happen in New Zealand. That’s why this research, that is dedicated to Aotearoa’s taiao [environment], is so important.”

Using TAIAO’s models, the researchers will determine how sediment like sand, mud, and silt will move between the open coast and our low-lying estuarine environments, which will help determine whether these areas will have the enough sediment to build new land and cope with rising sea levels (particularly in areas that are already naturally sinking).

Once completed, councils around Aotearoa New Zealand will be able to better support the communities living around coasts and estuaries that are particularly vulnerable and can plan how communities should move, grow, or take care of their land to minimise risk.

Data and Information from the programme will be published on the NZ SeaRise portal and will be continually updated to reflect new information and adapt to changing circumstances. As we have seen in recent months, we can be severely impacted by weather events, the intensity of which is very difficult to predict.

To learn more about the Our Changing Coast and NZ SeaRise programmes, visit their website.