NC Seagrant awards Dr. Lin Xiong grant to study dune restoration effectiveness across the Town of Nags Head

Written by: Dr. Lin Xiong

​In the Outer Banks of North Carolina, beach and dune ecosystems support millions of annual visitors and a ~2.3-billion-dollar tourism industry. But beach and dunes are subjected to acute and chronic erosion due to climate change, sea level rise, and increases in coastal development, population, and tourism. Beach renourishment projects and dune stabilization initiatives are often underway to build more resilient coastline. Better Beaches OBX (BBOBX) have planted beach grass and placed recycled Christmas trees along the dune line to help stabilize and build dunes in Outer Banks for the past several years. However, there are no measures of the effectiveness of these dune stabilization initiatives, which are key interests for BBOBX and local towns.

We will use lidar to quantify sediment budgets, foredune dynamics, and assess how various dune restoration activities impact coastal resilience along the North Carolina coast. Lidar is short for light detection and ranging. It detects ranges by emitting laser pulses and measuring travelling time from returns. Our Coastal Laser Scanner system includes the core instrument--TLS (Terrestrial Laser Scanner), also called ground-based lidar. The TLS in our lab, VZ400i, can emit up to 500,000 laser pulses per sec and acquire millions of measurements of coastal dunes and beaches in a very short time. It is like a digital twin of the coastal system with point clouds.

Traditional cross-shore profile surveys measured by Real Time Kinematic (RTK) GPS can only measure beach dynamics in 2D whereby changes in sand volume cannot be accurately measured with those limited profiles. The Coastal Laser Scanner is developed in the CSI’s Coasts & Oceans Observing Lab, which is led by Dr. David Lagomasino. Our Coastal Laser Scanner system can provide high resolution topographic survey in 3D and greatly improves coastal landscape visualization and interpretation.

Our goal is to conduct repeat hyper-resolution topographic surveys using our Coastal Laser Scanner at planted and non-planted beachfront dunes to assess the effectiveness of the stabilization activities which will provide preliminary data for future funding, provide training opportunities for students, and reinforce community partnerships between the ECU Outer Banks Campus, BBOBX, and the Town of Nags Head.