Rapid Lidar Deployment for Post-Hurricane Disaster Response: A Case Study

Abstract

This case study examines the potential implementation of Light Detection and Ranging (lidar) technology in rapid disaster response following Hurricane Helene in September 2024. The analysis focuses on how geospatial data acquisition through lidar could have enhanced damage assessment efficiency compared to legacy field methods. The study demonstrates that lidar technology has evolved beyond scientific research origins to become a viable operational tool for disaster response, particularly when rapid deployment protocols are essential to community safety and economic recovery. Further, the near complete US-wide availability of baseline high resolution aerial lidar through government efforts in the last decade enables a step change in practice through the detailed measurement of ground changes between baseline and disaster response lidar surveys.

Initial Response Limitations

In the immediate aftermath of Hurricane Helene, response efforts were significantly hampered by widespread communication network failures and infrastructure collapse. The option for ground level assessment did not exist because of the severity of ground transportation network failures and the critical need to preserve water, food, and lodging capacity for displaced residents. The conventional damage assessment methodology was forced to rely on aerial visual observations, which also presented critical limitations:

1. Coverage Inefficiency: The visual observation approach allowed only limited area coverage per day, creating delays in comprehensive damage assessment.
2. Geospatial Inaccuracy: Variable aircraft-to-ground distances and oblique look-angles resulted in uncertainties in correlating photos to ground locations.
3. Data Siloing: Multiple organizations conducted independent assessments without effective data-sharing mechanisms, resulting in fragmented and incomplete situational awareness for responding agencies.

In short, the initial response used a framework and technology stack that is over 20 years old.

Lidar Research Initiative

When well-intentioned established channels were unable to secure large-scale lidar acquisition immediately after the storm, Corey Scheip, Senior Geoscientist, BGC Engineering, and his team pursued an alternative path through research funding. This funding from the National Science Foundation and the National Center for Airborne Laser Mapping enabled regional lidar data acquisition for scientific research purposes approximately six weeks post-hurricane. While this timeframe was longer than optimal for immediate benefits, this was the first post-storm fixed wing lidar acquisition. The data were collected over two severely damaged and suddenly isolated communities in Western North Carolina – Bat Cave and Chimney Rock in the Hickory Nut Gorge and Green River Cover near Saluda, NC. The process demonstrated the potential for rapid deployment:

• Data Collection Timeline: Initial lidar surveys were conducted on November 15th
• Processing Completion: Final point clouds were delivered by mid-January
• Lidar Change Detection Analysis: Processing and hosting completed within 10 days
• Historical Comparison: Cambio Earth provided ground change analysis using lidar datasets from 2017, 2020, and 2024

Cambio Earth published the results of lidar-based continuous ground change using this rapid processing pipeline and immediately made the data available to all interested response agencies through an open-source license. 66 users from 13 agencies were added to view the LCD results and integrate them to their workflows. Additionally, university students are already working with the results in Cambio Earth to remotely learn in ways that otherwise would not be possible. 

The data highlighted the magnitude of landsliding and flooding from Helene and as of this writing, remains as the only available regional lidar post-storm.

Optimized Deployment Protocol

The case study reveals that with infrastructure and protocols in place, lidar data collection and processing could follow an accelerated timeline.

Engineering Applications

For engineers, geoscientists, and emergency response leadership, rapid lidar deployment offers several opportunities to shorten recovery time and improve certainty and responder safety in disaster response scenarios. Some are listed in this summary of capabilities:

Immediate Assessment Capabilities and Analysis 

• Reliable identification and measurement of ground changes from landslide and flood forces affecting communities, transportation, infrastructure, and water resources.
• Detailed damage assessments for compromised bridge and road networks, railroad corridors, dams, and telecommunication and utility transmission systems.
• Planning of safe emergency access routes to isolated communities and critical facilities
• High resolution 3D digital elevation models for civil engineers and contractors needing to build emergency recovery works and facilities.
• Generation of comprehensive landslide, scour, and other ground change inventories
• Mapping of stream migration and measurement of sediment changes in river systems
• Archival data set for documentation of post-event, pre-recovery site conditions
• Data for performing remote risk assessment for changes is slope stability and waterways. 

Recommendations for a resilient and improved future in disaster response. 

This case study demonstrates that rapid lidar deployment is a viable and valuable tool for disaster response. Beyond the lessons from Helene, there are examples of this protocol being applied within days and these recommendations are informed by what is possible now, rather than an aspirational theory. For emergency responders, engineers, and geoscientists, the following recommendations emerge:

1. Establish pre-event contracts with lidar data collection and analysis experts to enable rapid deployment.
2. Empower IT and other technical professionals to standardize data processing protocols and asset management systems to minimize turnaround time and avoid incompatibility breaks in digital data management.
3. Improve resiliency by preparing for lidar response in the days prior to the forecast for a highly destructive event.
4. Build data-sharing frameworks between responding organizations and execute on rolling data delivery for continuous post-event situational awareness.

The technology and implementation experience exists now for emergency response professionals to be making critical decisions informed by post-event lidar and ground change data within days of a disaster event, with continuous updates thereafter. 

When implemented correctly, post-event lidar is a tool that enables substantial improvements to multiple stakeholders in the recovery from disruptive weather and ground hazard triggered disasters.  The benefits to resiliency, trust in public officials, and economic recovery are real and measurable.