| “People want to know about the different shoreline types, such as marsh or swamp forest, how development may influence shoreline changes, and where sills, docks, and other structures are located. This map can help answer those questions.” | |
| Braxton Davis, North Carolina Division of Coastal Management |
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The first-ever digital map of North Carolina’s 12,000-mile estuarine shoreline will help coastal agencies, research institutions, and local governments identify shoreline changes and development trends. This information will be used to monitor those changes and make better-informed coastal resource management decisions.
“People want to know about the different shoreline types, such as marsh or swamp forest, how development may influence shoreline changes, and where sills, docks, and other structures are located. This map can help answer those questions,” says Braxton Davis, director of the North Carolina Division of Coastal Management.
The estuarine shoreline for the 20 coastal North Carolina counties is viewable via Internet Explorer on the North Carolina Shorelines and Oceanfront Setback Map (http://ims.ncdenr.org/Website/ncshore/viewer.htm). Featuring data from the best-available aerial imagery collected from 2006 through 2010, the site enables users to combine various data layers for customized and downloadable maps. GIS files can also be used in other maps and analyses.
The map provides detailed coastwide and county-level information. For instance, a sampling of searches yields answers on the average width of boat ramps, average length of groins, and total square footage of piers and docks. Facts are also provided on shoreline stabilization structures such as bulkheads and groins. This information can help coastal professionals weigh complex decisions that involve property rights, development, protecting coastal resources, and other concerns.
The North Carolina Division of Coastal Management partnered with East Carolina University to complete the map. The project partners received support through NOAA’s Office of Ocean and Coastal Resource Management under the Coastal Zone Enhancement Program.
The map became available in June 2012, and the early response has been positive. “Even before it came out, we were getting data requests from local governments and academia,” says Davis.
One group is using the map to analyze the condition of shoreline stabilization structures before and after 2011’s Hurricane Irene. Over the coming months, the agency will be holding more outreach events in coastal communities to explain the map’s usefulness.
Vast Area, Great Need
Marshes, rivers, creeks, and brackish sounds make up North Carolina’s 2.2 million acres of estuarine waters, one of the largest estuarine systems in the U.S. Until recently, much information on this resource was either anecdotal or area-specific, lacking the details needed for a more accurate, “big-picture” understanding.
“People would say things like, ‘North Carolina has enough bulkheads to stretch from Murphy to Maneo.’ That didn’t tell us anything about what percentage of the shoreline had bulkheads, or the effect of a particular bulkhead on an area,” emphasizes Mike Lopazanski, coastal and ocean policy manager for the division.
“Even permit records don’t tell the whole story,” notes Lopazanski, “because what is permitted is not necessarily what ends up being built. We needed solid data for our agency and also to give to the North Carolina Coastal Resources Commission so they could make informed decisions about situations on the ground.”
Davis acknowledges that efforts by several Southeast and Mid-Atlantic states to map their estuarine shorelines—and the great information that is being discovered—inspired North Carolina to spearhead its own project. “For decades Virginia and Maryland have partnered with researchers to map estuarine shorelines and produce ‘shoreline situation reports,’ and I’ve been told these are some of the most useful projects they’ve ever supported,” he notes.
Steps Forward, Lessons Learned
North Carolina’s mapping effort began with a pilot project in December 2006. Seeking a better understanding of stakeholders’ mapping needs and expectations, the project partners held a summit in December 2007. Representatives attended from state and federal resource and regulatory agencies, academic institutions, and nongovernmental organizations.
By 2008, a working group had been formed to guide the project and establish methods for collecting the aerial imagery and processing the results. County by county, the partners and working group collected the most recent imagery available with the highest possible resolution, using color imagery because of its better visibility and contrast.
“While collecting information for the map, we found that communication was key—not only within our working group but also with other agencies, universities, and consultants,” says Lopazanski. “Establishing a consistent methodology and limiting the number of shoreline categories also turned out to be important, because any more than five shoreline types made the mapping too difficult.”
Building Momentum
A follow-up summit in spring 2013 will go over the results of the mapping project and address possible tweaks and improvements to the methods. Plans are in the works to make the map viewable in several additional browsers and to update the detailed structures inventory. Davis and Lopazanski also hope to build on the map’s effectiveness by finding support for regular imagery collection and shoreline updates.
“Regular data updates and a structures inventory can tell us more about shoreline changes over time and whether some erosion-control methods work especially well, to mention just a few uses,” notes Davis. “With these data sets, we can make better decisions about the most favorable areas for erosion control and the best methods to accomplish it.”
For more information on the North Carolina Shorelines and Oceanfront Setback Map, contact Braxton Davis at Braxton.Davis@ncdenr.gov or (252) 808-2808. You can also learn more by visiting http://ims.ncdenr.org/Website/ncshore/viewer.htm.
North Carolina Estuarine Shoreline Facts
- 12,625 Total Shoreline Miles
- 26,612 Total Number of All Shoreline Structures
- 825 Total Acres of All Shoreline Structures
- 604 Total “Shoreline Stabilization Structure” Miles (groins, sills, bulkheads, and other)
