Hard Corps scientist, Hardcore surfer – Dr. Jeffrey Hanson at the Field Research Facility at Duck Pier, NC. Photo: 2M

Q & A

CORPS VALUES

EVERY SO-CALLED "EVIL" CONTAINS AN ELEMENT OF GOOD -- THAT INCLUDES THE ARMY CORPS OF ENGINEERS 

By Matt Walker/ Surfing Magazine 

They're the guys you love to hate. Dumpers of sand. Dredgers of breaks. Builders and breakers of groins. You know them better as the U.S. Army Corps of Engineers. And if you're looking for a place on which to focus your negative energy, it's the Field Research Facility in Duck, NC. This spear of steel and concrete juts 1840 feet into the Atlantic Ocean -- the longest research pier on the whole East Coast. Beneath the shadow of a 120-foot observation tower, surrounded by strange amphibious vehicles, here is where the Army Corps performs all of its coastal impact observations. Every plan to move a lighthouse; every Jersey nourishment project, runs back to Duck. But the place isn't pure evil. In fact, more work goes toward demystifying ocean processes here than almost any place on earth -- and certainly anywhere on the Atlantic Seaboard. "My main focus is waves," says Research Oceanographer Dr. Jeffrey Hanson. "To understand wave physics, how waves transition across the continental shelf and impact the coast, and to develop better models." 

Blonde, smiling, and eager to please, 48-year-old Hanson spent 18 years at Johns Hopkins before joining the Army Corps in 2003 because he "got tired of studying waves on a computer and looking out at a parking lot." Today, he and a team of researchers, including Chuck Long and Kent Hathaway, are refining a new nearshore wave modeling system aimed to negotiate every detail within 100 yards of the coastline. And though the system's primary purpose is to protect buildings, surfers may end up being one of the biggest beneficiaries.

ESM: Would you say the Field Research Facility is "ground zero" for the Army Corps' work?
JH: Well, we're really just a satellite lab for the research and development center in Vicksburg, Mississippi. We're the guys who observe the coastal processes for the Army Corps, collecting data to help validate and improve coastal processes models. But from a coastal observation standpoint, we're definitely ground zero.  

ESM: What kind of work goes on at any given time?
JH: Historically, the pier has been focused on understanding the processes behind the movement of sand. Why are the beaches eroded in some spots and not others? What can we do about it? But my role is to expand that and provide a place here in North Carolina where we can demonstrate and validate them and continue to improve them. 

ESM: So if computer models are basically assumptions based on prior data, your job is to develop even better models with newer data.
JH: Exactly. We break down Mother Nature into its basic processes, its driving mechanisms: winds, obviously; tides; the winds drive currents and also generate waves; waves and currents both work on the shoreline as far as transporting sand. Right now, we have separate models for all these processes. What we're working toward is coupling them all together so that if we have the winds predicted right, we could feed them in and start predicting what a particular hurricane would do to the Outer Banks -- where a new inlet might open, how an old one might close up, what sort of flooding we could expect from X category storm coming from X direction and lasting for X many days. It's a risk-based approach that we want to be able to get to, so we can go to any particular location and really evaluate the vulnerability of that location to episodic events. And in the process, we continually improve our modeling capability. But don't get the impression that the Army Corps of Engineers is operating alone. We've formed partnerships with the University of North Carolina, FEMA, and in particular the NOAA and the National Centers for Environmental Prediction, which includes Hendrik Tolman, the developer of WaveWatch III, which is the global basin scale wave model that NOAA operates.  

ESM: But that's all open ocean modeling.
JH: Yes. Now the trick is how to intelligently bring those waves in and really know what they're doing at the beach. When you have waves coming across a shelf, there's a lot of physics going on. The waves feel the bottom. They attenuate from bottom friction. They shoal up. They start to break and lose energy that way. And we have to have all those physics right. For that, you need to go to a higher resolution wave model such as SWAN (Simulating Waves Nearshore) -- which the National Weather Service runs for several places -- and the model the Army Corps is developing called STWAVE. We have an analysis technique that's unique which allows us to split apart a wave field into its individual wind, sea, and swell components and track them over time. Rather than just looking at the total wave height out there and the mean direction, we're breaking the waves down into their individual components from distinct storms. And we look at how these different wave models can reproduce this. Right now, we have Eve Devaliere of UNC running SWAN here at the pier and putting results on the web, and we compare predictions with actual results to make improvements to STWAVE, which we believe will have even better shallow water physics for more accuracy.  

ESM: So when I drive south and the waves are half the size as predicted, it's SWAN's fault -- or whatever nearshore wave model a website might be running.
JH: [laughs]... Well, sort of. One thing people have to remember with any computer model is that garbage in equals garbage out. If you don't have the winds right, if you don't have the boundary forcing of the waves right, you can't possibly predict; the model can only work with what you give it. 

ESM: How close is the SWAN model?
JH: For the one we have on the Outer Banks, you get a prediction every 500 meters. And it's probably good for... say a few hundred yards offshore, but not really good up against the beach. What SWAN is doing is taking it from 60 miles offshore and bringing it within a half-mile of shore. The next phase will be to bring it in from a half-mile offshore and up to the beach. 

ESM: Which is good for us, because that's where waves break.
JH: That's right. And we'll be working with things like breaking criteria, so you can estimate how the breakers will change up and down the beach.

ESM: Like within a mile?
JH: Yeah. 

ESM: But not, say, a block.
JH: Well... [chuckles]. Again, it's all progressing in stages.  

ESM: So where's your model at now?
JH: This year, we'll get STWAVE up and going. And that's being developed by Don Resio and Jane Smith at our main lab in Vicksburg, and what we'll be here is a validation site. We're also working with professor Rich Luettich at UNC to get STWAVE coupled with ADCIRC, which is a circulation model, so we'll correctly get the wave and current interactions in the model. When you're around inlets and shoals and sandbars and whatnot, the currents become very important in dictating what the wave climate is. Those are the forces that move sand. So we have another team working on a sediment transport morphology, so we can eventually predict how the beaches are gonna respond to the waves and currents, and that includes sandbar migrations and formations. Eventually, it would be nice to get down to the level of detail of understanding how these sandbars, and how the beach morphology -- the shape of the beach from the sand dune out to the sandbars -- how they respond over the time to the winds, waves, and currents. That's where we're trying to get to. Because if you have a hurricane that erodes away a sand dune, you're more likely to have inundation and flooding in an area behind that dune. We have a 25-year database of video imagery and acoustic surveys (of sand movement). So the next phase is to use that data to validate computer models of how the beaches and sandbars are evolving. We have a team working on that, a joint effort between the University of Delaware, Army Corps, and Delft University in the Netherlands. 

ESM: Is that info you're planning on publishing?
JH: That's definitely a goal. It's a bit far down the road right now. You have to take this research a step at time. 

ESM: Five years? Ten years?
JH: I'd like to say three to five.  

ESM: So at some point will that all be available online? You'd go to the FRF page and see how the sandbars shifted on Pea Island after a storm?
JH: Well, our role here is to develop the capability and then transition it elsewhere for operational use. Our role won't be in an operational capacity, but we'll develop the technology and then transfer it over to whoever will make it publicly available. Our models all have a community emphasis, which means they're technically available to everyone.  

ESM: That's the same idea behind accessing NASA photos or NOAA photos; it's your tax dollars at work and open to the public. And then once you have it ready here, then what? Take it to the rest of the world?
JH: That's the idea. 

ESM: Obviously, the Corps doesn't have the best reputation among surfers when it comes to beach replenishment and destroying breaks; but here's a clear case where -- even though the end goal isn't surfing-related -- surfers will be major beneficiaries. How do you explain the paradox?
JH: I don't know about the Corps as a whole. I have a more local stance. I have a lot of friends here who surf, I surf myself, and I want to provide something for the surfing community based on our work. So it's more of a local effort: the community is nice enough to put up with us, and this is something nice we can give back to them that'll have some value.  

ESM: And your goal is to produce what, forecasts that are twice as good? Fifty percent better? Ten percent?
JH: [laughs]... You're not gonna get me to say that. 

ESM: Come on, now! We want concrete answers. We want to know what the waves will be like on June 10th, 2008, within a foot!
JH: Let's just say we're looking at continually making steady improvements in wave forecast capability. I think the Corps is committed to that. 

Dr. Hanson would, once again, like to recognize everyone involved in STWAVE and its surrounding projects, including Don Resio, Jane Smith, Rich Luettich, Eve Devaliere, Chuck Long, Kent Hathaway, and Harry Friebel -- and his son Jason for letting him catch a few waves. For more info and to keep tabs on STWAVE's progress and other projects, go to www.frf.usace.army.mil

"And miles to go before I surf...?" If the new A.C.O.E. technology is a go, maybe not. Pea Island, NC. Photo: Dugan