Editor’s note: This story is part of “Washout: Our vanishing beaches,” a series about the reshaping of Rhode Island’s shoreline. This interview has been edited for length and clarity.
TRANSCRIPT:
LUIS HERNANDEZ: Professor Walsh, it’s a pleasure. Thanks so much.
J.P. WALSH: Nice to meet you.
HERNANDEZ: Professor, how different do our beaches look right now after the winter storm? Because that’s the thing a lot of people are thinking about.
WALSH: Yeah, well, so we had a tough winter with a number of storms like normal, but we had some particularly strong storms this winter that really took a toll along our shoreline. When we actually measure the change, the beach itself, like the position of the shoreline today, is in many ways similar to places last fall, but we saw a lot of erosion of either the dunes or the bluff at the upper edge of the beach because we had these really big storms that had high water level and large waves that eroded the upper boundary of the beach.
HERNANDEZ: So what can you tell us about the last few decades? How much has our shoreline changed in that time?
WALSH: When you look using aerial imaging over decades, we get rates on the order of five feet per year of erosion. That’s kind of the high end of the rates. Many parts of our coastline maybe are not either eroding at all, like where you have rocky coasts that are more resistant to erosion. But places where we have sandy shorelines based on sort of the long-term change rates, we’re looking at higher end of up to about five feet per year averaging over decades of time. We measured this winter, at many places, rates of change over 15 feet per year; that’s annualized. Pretty high erosion just this winter at many places and along the upper beach of our coast.
HERNANDEZ: Can you tell me what beaches are seeing that kind of erosion?
WALSH: Yeah. Places like South Kingstown Town Beach. Roy Carpenter’s Beach is well known for high rates. I mean, Rhode Island, because we have a complex geology, it’s really quite variable what we see along the shoreline, and it also varies not only in space – sort of along the shoreline – but also with time. The rates are very variable, maybe from one storm or a year to the next.
HERNANDEZ: Whenever I talk to a scientist, I always want to know, can you predict the future?
WALSH: No, but I think we can gain good insights into what the future will look like using the past and that’s sort of a core concept of the field of geology. I have real concern because, just in the last few years, we’ve had – not just this winter, but the winter before – some really powerful winter storms. Typically in New England, we refer to our winter storms as nor’easters because the winds dominantly come out of the northeast and they bring cold weather, often snow. More recently, we’ve had winter storms pass directly over us or north of us and that’s brought southerly, or southeast, winds, and that’s brought strong waves and wind on our coast. That’s caused quite a lot of erosion.
HERNANDEZ: Whenever we do this story, I’ll often mention that climate change is a part of this. I wanted you to explain to us, what are the factors driving this very fast erosion?
WALSH: Great question. A beach, when you go to it, the primary control is the geology of the area. Some places we have nice, sandy beaches; others, we don’t. Of course, there’s the oceanography; the waves, the tides, the currents that act to reshape the coastline over time. And then when you go to a beach on a given day, what it looks like is a function of its history, both over the long-term as well as the last month or two. So what erosion might look like at a beach is a function of that geology as well as how humans have altered it, but then how the oceanography – the storms and weather – has reshaped it over recent or past time.
HERNANDEZ: You mentioned Rhode Island is unique. As a scientist, what are some of the challenges you face trying to measure beach erosion here.
WALSH: When we talk about beach erosion, many of us are probably thinking about when we have erosion that affects the houses along the beach or affects maybe the beaches that we visit and the structures or the roadways. The beach itself – sort of the upland edge of the beach – is where we start having houses or roads. That’s where we start feeling vulnerability. The beach itself, though, is a dynamic place where we lay our beach towels and that will change a lot over the season and after each storm. So when we try to measure beach change, we have to be clear about what we’re measuring. Are we measuring from the actual position of the ocean at a certain time? Or are we measuring maybe the upper edge of the beach and how that’s moving over time?
HERNANDEZ: Some people advocate for beach renourishment. Other people say no, nature’s going to take it anyway. Let it go. We’ll just retreat. What do you think about that?
WALSH: My stance is it is, I try to be a scientist and have a neutral opinion on whether it’s good or bad. You’re right; with storms and sea-level rise, probably the beach is going to erode anyway and it may happen very quickly, so any investment made on beach nourishment can disappear quickly, as we heard about this winter up in Massachusetts. But some communities have made that commitment because they really depend on having a healthy beach system, so that investment is warranted. It’s one that will need to be sustained. The other limit to this is the cost involved and the availability of sand because sand is not everywhere in the ocean, although people might think so. It is a finite resource in certain areas and that’s one of the challenges that many communities face.
HERNANDEZ: Professor J.P. Walsh is a coastal scientist at URI. Professor, thanks very much for the insight. I really appreciate it.
WALSH: Thanks, Luis. Pleasure to meet you.
Click here to read more from “Washout: Our vanishing beaches,” a series about the reshaping of Rhode Island’s shoreline.
