Terrestrial Laser Scanning: An Operational Tool for Fuel Hazard Mapping?

Abstract

Fuel hazard estimates are vital for the prediction of fire behaviour and planning fuel treatment activities. Previous literature has highlighted the potential of Terrestrial Laser Scanning (TLS) to be used to assess fuel properties. However, operational uptake of these systems has been limited due to a lack of a sampling approach that balances efficiency and data efficacy. This study aims to assess whether an operational approach utilising Terrestrial Laser Scanning (TLS) to capture fuel information over an area commensurate with current fuel hazard assessment protocols implemented in South-Eastern Australia is feasible. TLS data were captured over various plots in South-Eastern Australia, utilising both low- and high-cost TLS sensors. Results indicate that both scanners provided similar overall representation of the ground, vertical distribution of vegetation and fuel hazard estimates. The analysis of fuel information contained within individual scans clipped to 4 m showed similar results to that of the fully co-registered plot (cover estimates of near-surface vegetation were within 10%, elevated vegetation within 15%, and height estimates of near-surface and elevated strata within 0.05 cm). This study recommends that, to capture a plot in an operational environment (balancing efficiency and data completeness), a sufficient number of non-overlapping individual scans can provide reliable estimates of fuel information at the near-surface and elevated strata, without the need for co-registration in the case study environments. The use of TLS within the rigid structure provided by current fuel observation protocols provides incremental benefit to the measurement of fuel hazard. Future research should leverage the full capability of TLS data and combine it with moisture estimates to gain a full realisation of the fuel hazard.

Using Pre-Fire High Point Cloud Density LiDAR Data to Predict Fire Severity in Central Portugal

“…However, compared to airborne LiDAR, the area coverage of TLS is small [103]. Although methods have been developed to use TLS as an operational fuel hazard observation technology [104], wall-to-wall assessments over large areas are not feasible. In this sense, future research in fire severity behavior should address the use of mobile laser scanning (MLS), a new remote sensing technique that has not much been considered in forestry applications [105] and wildfire science [106].…”

Terrestrial 3D Laser Scanning for Ecosystem and Fire Effects Monitoring

“…Batchelor and others (2023) illustrate the use of single scans of the FARO® Focus 3D S120 terrestrial laser scanner (FARO Technologies Inc., Lake Mary, FL, USA) for estimating new structural complexity metrics in Pacific Northwest forests. Many studies have used multiple merged scans to predict grass, shrub, tree, or fuel attributes at various scales and using a variety of metrics of interest (e.g., Alonso-Rego and others 2020, Cooper and others 2017, Loudermilk and others 2009, Olsoy and others 2014, Wallace and others 2022). Merged FARO® Focus scans were used to relate structural complexity of mixed pine-hardwoods forests of the southern Appalachians to vascular plant biodiversity (Walter and others 2021).…”

Terrestrial Laser Scan Metrics Predict Surface Vegetation Biomass and Consumption in a Frequently Burned Southeastern U.S. Ecosystem

“…Fortunately, recent advances in lidar technology have allowed for a transition from research to management applications, specifically through available low-cost, portable push button instruments [35,36]. Instrument types range from hand-held or vehicle-mounted scanners [37,38], unmanned aerial vehicle scanners [39], stationary scanners [40][41][42], and even mobile phone apps [43]. These all vary in quality, accuracy, and inherent laser capabilities (range, output point density, number of returns), that impacts each desired forest measurement attribute [35,44].…”