Drone Mapping for Coastal Erosion Monitoring and Management

Coastal erosion is one of the most dynamic and consequential geomorphic processes on Earth. Shorelines change continuously — advancing and retreating in response to waves, storms, sea level rise, and human activities. Managing this change requires precise, repeatable measurements over time.

Drone mapping has become an essential tool for coastal scientists, engineers, and managers who need to understand and respond to coastal change.

Establishing an accurate baseline is the foundation of any coastal monitoring program. A drone survey produces:

• High-resolution orthomosaic — detailed imagery of the shoreline and beach
• DEM — precise elevation data for the beach and dune system
• Shoreline position — the precise location of the water-land boundary at the time of the survey

This baseline allows future surveys to be compared to initial conditions, quantifying the rate and pattern of change.

Coastal monitoring requires repeat surveys at regular intervals — monthly, seasonally, or after significant storm events. Comparing surveys from different dates reveals:

• Shoreline position change — how far the shoreline has advanced or retreated
• Beach volume change — how much sand has been gained or lost
• Dune erosion — changes in dune height and volume
• Infrastructure exposure — whether coastal infrastructure is becoming exposed by erosion

Major storms can cause dramatic coastal changes in a matter of hours. Post-storm drone surveys document:

• Storm erosion — the extent and volume of sand removed by the storm
• Overwash — areas where storm waves overtopped the beach and dune
• Infrastructure damage — damage to seawalls, revetments, and other coastal structures
• Recovery — how quickly the beach recovers after the storm

Beach nourishment — placing sand on eroding beaches to restore beach width — is a common coastal management strategy. Drone mapping supports nourishment projects:

A pre-nourishment survey establishes the baseline conditions — beach width, volume, and profile — before sand placement begins.

During nourishment operations, drone surveys track the progress of sand placement and verify that the nourishment template is being achieved.

After nourishment, regular drone surveys track how the nourished beach evolves — how quickly it erodes, where sand is redistributed, and how long the nourishment lasts.

Coastal infrastructure — seawalls, revetments, jetties, and groins — requires regular inspection. Drone surveys document:

• Structure condition — visible damage, displacement, and deterioration
• Scour — erosion at the base of structures
• Overtopping — evidence of wave overtopping
• Backshore conditions — conditions behind the structure

Coastal dunes provide natural protection against storm surge and erosion. Drone mapping supports dune management:

• Dune volume — measuring the volume of sand stored in the dune system
• Dune height — tracking changes in dune crest elevation
• Vegetation — mapping dune vegetation that stabilizes the dune surface
• Blowouts — identifying areas where wind erosion has created gaps in the dune

As sea levels rise, low-lying coastal areas become increasingly vulnerable to flooding and erosion. Drone-produced DEMs support vulnerability assessment:

• Elevation mapping — identifying areas below specific elevation thresholds
• Inundation modeling — modeling flood extents under different sea level rise scenarios
• Infrastructure vulnerability — identifying infrastructure at risk from sea level rise

Coastal erosion monitoring requires precise, repeatable measurements over time — exactly what drone mapping provides. For coastal scientists, engineers, and managers, drone surveys are an essential tool for understanding and responding to coastal change.

Contact Blackridge Geospatial to discuss drone mapping services for your coastal monitoring program.