scholarly journals Decomposing the Interactions between Fire Severity and Canopy Fuel Structure Using Multi-Temporal, Active, and Passive Remote Sensing Approaches

Fire ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 7 ◽  
Author(s):  
Nicholas S. Skowronski ◽  
Michael R. Gallagher ◽  
Timothy A. Warner
Keyword(s):  
Laser Scanning ◽  
Treatment Effectiveness ◽  
Fire Severity ◽  
Fire Behavior ◽  
Three Dimensional ◽  
Structural Heterogeneity ◽  
Behavior Modeling ◽  
Fuel Loading ◽  
Subtle Difference ◽  
Multi Temporal

Within the realms of both wildland and prescribed fire, an understanding of how fire severity and forest structure interact is critical for improving fuels treatment effectiveness, quantifying the ramifications of wildfires, and improving fire behavior modeling. We integrated high resolution estimates of fire severity with multi-temporal airborne laser scanning data to examine the role that various fuel loading, canopy shape, and other variables had on predicting fire severity for a complex of prescribed fires and one wildfire and how three-dimensional fuels changed as a result of these fires. Fuel loading characteristics were widely variable, and fires were ignited using a several techniques (heading, flanking, and backing), leading to a large amount of variability in fire behavior and subsequent fire effects. Through our analysis, we found that fire severity was linked explicitly to pre-fire fuel loading and structure, particularly in the three-dimensional distribution of fuels. Fire severity was also correlated with post-fire fuel loading, forest structural heterogeneity, and shifted the diversity and abundance of canopy classes within the landscape. This work demonstrates that the vertical distribution of fuel is an important factor and that subtle difference has defined effects on fire behavior and severity.

scholarly journals Chronosequence of Fuel Loading and Fuel Depth Following Forest Rehabilitation Frill Treatment of Tanoak to Release Douglas-Fir: A Case Study from Northern California

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 691
Author(s):  
Raven M. Krieger ◽  
Brian E. Wall ◽  
Cody W. Kidd ◽  
John-Pascal Berrill
Keyword(s):  
Woody Debris ◽  
Fire Severity ◽  
Fire Behavior ◽  
Fire Effects ◽  
Behavior Modeling ◽  
Northern California ◽  
Fuel Loading ◽  
Excessive Competition ◽  
Pre Treatment ◽  
Forest Rehabilitation

There is concern that forest management activities such as chemical thinning may increase hazardous fuel loading and therefore increase risk of stand-replacing wildfire. Chemical thinning, often accomplished by frill treatment of unwanted trees, leaves trees standing dead for a time before they fall and become surface fuels. In coastal northern California, frill treatment is used as a forest rehabilitation treatment that removes tanoak (Notholithocarpus densiflorus) to release merchantable conifers from excessive competition. We studied fuel bed depth and fuel loading after frill treatment of tanoak along a 16-year chronosequence that substituted space for time. The total depth of fuel bed was separated into woody fuels, litter, and duff. The height of each layer was variable and greatest on average in post-treatment year 5 after treated tanoak had begun to break apart and fall. Initially, the evergreen tanoak trees retained their foliage for at least a year after treatment. Five years after treatment, many tanoak had fallen and transitioned to become fine- and coarse woody debris. After 11 years, the larger pieces of down wood were mostly classified as rotten. After 16 years, the fuel loading appeared roughly equivalent to pre-treatment levels, however we did not explicitly test for differences due to potential confounding between time and multiple factors such as inter-annual climate variations and site attributes. Nevertheless, our data provide some insight into changes in surface fuel characteristics due to rehabilitation treatments. These data can be used as inputs for fire behavior modeling to generate indicative predictions of fire effects such as fire severity and how these change over time since treatment.

scholarly journals Terrestrial laser scanning for quantifying small-scale vertical movements of the ground surface in Artic permafrost regions

2017 ◽  
Author(s):  
Sabrina Marx ◽  
Katharina Anders ◽  
Sofia Antonova ◽  
Inga Beck ◽  
Julia Boike ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Ground Surface ◽  
Terrestrial Laser Scanning ◽  
Spatial Sampling ◽  
Small Scale ◽  
Vertical Movements ◽  
North East ◽  
Multi Temporal ◽  
Permafrost Regions

Abstract. Three-dimensional data acquired by terrestrial laser scanning (TLS) provides an accurate representation of Earth's surface, which is commonly used to detect and quantify topographic changes on a small scale. However, in Arctic permafrost regions the tundra vegetation and the micro-topography have significant effects on the surface representation in the captured dataset. The resulting spatial sampling of the ground is never identical between two TLS surveys. Thus, monitoring of heave and subsidence in the context of permafrost processes are challenging. This study evaluates TLS for quantifying small-scale vertical movements in an area located within the continuous permafrost zone, 50 km north-east of Inuvik, Northwest Territories, Canada. We propose a novel filter strategy, which accounts for spatial sampling effects and identifies TLS points suitable for multi-temporal deformation analyses. Further important prerequisites must be met, such as accurate co-registration of the TLS datasets. We found that if the ground surface is captured by more than one TLS scan position, plausible subsidence rates (up to mm-scale) can be derived; compared to e.g. standard raster-based DEM difference maps which contain change rates strongly affected by sampling effects.

Fire Severity, Changing Scales, and How Things Hang Together

1991 ◽  
Vol 1 (1) ◽  
pp. 23 ◽  
Author(s):  
SJ Simard
Keyword(s):  
Wildland Fire ◽  
Fire Severity ◽  
Fire Behavior ◽  
Three Dimensional ◽  
Space Time ◽  
Management Systems ◽  
Dimensional Structure ◽  
Natural Evolution ◽  
Generic Framework ◽  
Scale Range

The paper describes attributes of space, time, and process in terms of their relations to wildland fire. It then presents a generic framework, based on eight interrelated scale classes for space, time, and process. The effects of changing scales are discussed in a wildland fire context. A five-layered (society, management, systems, fire, and weather), three-dimensional structure for wildland fire is presented. The paper also discusses inefficiencies and inadequacies inherent in systems with inconsistent scales. It then focuses on the effects of scale differences between fire behavior and fire danger and on an acceptable scale range suggested by the natural evolution of these two systems. The paper then defines fire severity and proposes two types of severity models — situation and extended. Finally, it discusses fundamental differences between situational and extended severity and appropriate space, time, and process attributes for both types of severity models.

Fuel treatments alter the effects of wildfire in a mixed-evergreen forest, Oregon, USA

2005 ◽  
Vol 35 (12) ◽  
pp. 2981-2995 ◽  
Author(s):  
Crystal L Raymond ◽  
David L Peterson
Keyword(s):  
Tree Mortality ◽  
Fire Regime ◽  
Fire Severity ◽  
Fire Behavior ◽  
Evergreen Forest ◽  
Fire Intensity ◽  
Crown Fire ◽  
Fuel Loading ◽  
Fuel Treatments ◽  
Surface Fire

We had the rare opportunity to quantify the relationship between fuels and fire severity using prefire surface and canopy fuel data and fire severity data after a wildfire. The study area is a mixed-evergreen forest of southwestern Oregon with a mixed-severity fire regime. Modeled fire behavior showed that thinning reduced canopy fuels, thereby decreasing the potential for crown fire spread. The potential for crown fire initiation remained fairly constant despite reductions in ladder fuels, because thinning increased surface fuels, which contributed to greater surface fire intensity. Thinning followed by underburning reduced canopy, ladder, and surface fuels, thereby decreasing surface fire intensity and crown fire potential. However, crown fire is not a prerequisite for high fire severity; damage to and mortality of overstory trees in the wildfire were extensive despite the absence of crown fire. Mortality was most severe in thinned treatments (80%–100%), moderate in untreated stands (53%–54%), and least severe in the thinned and underburned treatment (5%). Thinned treatments had higher fine-fuel loading and more extensive crown scorch, suggesting that greater consumption of fine fuels contributed to higher tree mortality. Fuel treatments intended to minimize tree mortality will be most effective if both ladder and surface fuels are treated.

scholarly journals Inter-annual surface evolution of an Antarctic blue-ice moraine using multi-temporal DEMs

2015 ◽  
Vol 3 (4) ◽  
pp. 1317-1344 ◽  
Author(s):  
M. J. Westoby ◽  
S. A. Dunning ◽  
J. Woodward ◽  
A. S. Hein ◽  
S. M. Marrero ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Austral Summer ◽  
Multiscale Model ◽  
Aerial Photographs ◽  
Dynamic Surface ◽  
Surface Evolution ◽  
Multi Temporal ◽  
Fine Resolution ◽  
Dem Differencing

Abstract. Multi-temporal and fine resolution topographic data products are being increasingly used to quantify surface elevation change in glacial environments. In this study, we employ 3-D digital elevation model (DEM) differencing to quantify the topographic evolution of a blue-ice moraine complex in front of Patriot Hills, Heritage Range, Antarctica. Terrestrial laser scanning (TLS) was used to acquire multiple topographic datasets of the moraine surface at the beginning and end of the austral summer season in 2012/2013 and during a resurvey field campaign in 2014. A complementary topographic dataset was acquired at the end of season 1 through the application of Structure-from-Motion (SfM) photogrammetry to a set of aerial photographs taken from an unmanned aerial vehicle (UAV). Three-dimensional cloud-to-cloud differencing was undertaken using the Multiscale Model to Model Cloud Comparison (M3C2) algorithm. DEM differencing revealed net uplift and lateral movement of the moraine crests within season 1 (mean uplift ∼ 0.10 m), with lowering of a similar magnitude in some inter-moraine depressions and close to the current ice margin. Our results indicate net uplift across the site between seasons 1 and 2 (mean 0.07 m). This research demonstrates that it is possible to detect dynamic surface topographical change across glacial moraines over short (annual to intra-annual) timescales through the acquisition and differencing of fine-resolution topographic datasets. Such data offer new opportunities to understand the process linkages between surface ablation, ice flow, and debris supply within moraine ice.

scholarly journals An Accurate TLS and UAV Image Point Clouds Registration Method for Deformation Detection of Chaotic Hillside Areas

2019 ◽  
Vol 11 (6) ◽  
pp. 647 ◽  
Author(s):  
Yufu Zang ◽  
Bisheng Yang ◽  
Jianping Li ◽  
Haiyan Guan
Keyword(s):  
Laser Scanning ◽  
Detection Method ◽  
Three Dimensional ◽  
Point Clouds ◽  
Image Point ◽  
Numerical Representation ◽  
Registration Method ◽  
3D Point Clouds ◽  
Multi Temporal ◽  
Difficult Terrain

Deformation detection determines the quantified change of a scene’s geometric state, which is of great importance for the mitigation of hazards and property loss from earth observation. Terrestrial laser scanning (TLS) provides an efficient and flexible solution to rapidly capture high precision three-dimensional (3D) point clouds of hillside areas. Most existing methods apply multi-temporal TLS surveys to detect deformations depending on a variety of ground control points (GCPs). However, on the one hand, the deployment of various GCPs is time-consuming and labor-intensive, particularly for difficult terrain areas. On the other hand, in most cases, TLS stations do not form a closed loop, such that cumulative errors cannot be corrected effectively by the existing methods. To overcome these drawbacks, this paper proposes a deformation detection method with limited GCPs based on a novel registration algorithm that accurately registers TLS stations to the UAV (Unmanned Aerial Vehicle) dense image points. First, the proposed method extracts patch primitives from smoothed hillside points, and adjacent TLS scans are pairwise registered by comparing the geometric and topological information of or between patches. Second, a new multi-station adjustment algorithm is proposed, which makes full use of locally closed loops to reach the global optimal registration. Finally, digital elevation models (DEMs, a DEM is a numerical representation of the terrain surface, formed by height points to represent the topography), slope and aspect maps, and vertical sections are generated from multi-temporal TLS surveys to detect and analyze the deformations. Comprehensive experiments demonstrate that the proposed deformation detection method obtains good performance for the hillside areas with limited (few) GCPs.

scholarly journals Prediction of Fuel Loading Following Mastication Treatments in Forest Stands in North Idaho, USA

2020 ◽  
Vol 12 (17) ◽  
pp. 7025
Author(s):  
Ryer Becker ◽  
Robert Keefe
Keyword(s):  
Fire Behavior ◽  
Stand Density ◽  
Post Treatment ◽  
Behavior Modeling ◽  
Fuel Reduction ◽  
Fuel Loading ◽  
Stem Size ◽  
Fuel Loads ◽  
Pre Treatment ◽  
Mean Square Errors

Fuel reduction in forests is a high management priority in the western United States and mechanical mastication treatments are implemented common to achieve that goal. However, quantifying post-treatment fuel loading for use in fire behavior modeling to forecast treatment effectiveness is difficult due to the high cost and labor requirements of field sampling methods and high variability in resultant fuel loading within stands after treatment. We evaluated whether pre-treatment LiDAR-derived stand forest characteristics at 20 m × 20 m resolution could be used to predict post-treatment surface fuel loading following mastication. Plot-based destructive sampling was performed immediately following mastication at three stands in the Nez Perce Clearwater National Forest, Idaho, USA, to correlate post-treatment surface fuel loads and characteristics with pre-treatment LiDAR-derived forest metrics, specifically trees per hectare (TPH) and stand density index (SDI). Surface fuel loads measured in the stand post-treatment were consistent with those reported in previous studies. A significant relationship was found between the pre-treatment SDI and total resultant fuel loading (p = 0.0477), though not between TPH and fuel loading (p = 0.0527). SDI may more accurately predict post-treatment fuel loads by accounting for both tree number per unit area and stem size, while trees per hectare alone does not account for variations of tree size and subsequent volume within a stand. Relatively large root-mean-square errors associated with the random forest models for SDI (36%) and TPH (46%) suggest that increased sampling intensity and modified methods that better account for fine spatial variability in fuels resulting from within-stand conditions, treatment prescriptions and machine operators may be needed. Use of LiDAR to predict fuel loading after mastication is a useful approach for managers to understand the efficacy of fuel reduction treatments by providing information that may be helpful for determining areas where treatments can be most beneficial.

scholarly journals Interannual surface evolution of an Antarctic blue-ice moraine using multi-temporal DEMs

2016 ◽  
Vol 4 (2) ◽  
pp. 515-529 ◽  
Author(s):  
Matthew J. Westoby ◽  
Stuart A. Dunning ◽  
John Woodward ◽  
Andrew S. Hein ◽  
Shasta M. Marrero ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Austral Summer ◽  
Multiscale Model ◽  
Aerial Photographs ◽  
Dynamic Surface ◽  
Surface Evolution ◽  
Multi Temporal ◽  
Fine Resolution ◽  
Dem Differencing

Abstract. Multi-temporal and fine-resolution topographic data products are increasingly used to quantify surface elevation change in glacial environments. In this study, we employ 3-D digital elevation model (DEM) differencing to quantify the topographic evolution of a blue-ice moraine complex in front of Patriot Hills, Heritage Range, Antarctica. Terrestrial laser scanning (TLS) was used to acquire multiple topographic datasets of the moraine surface at the beginning and end of the austral summer season in 2012/2013 and during a resurvey field campaign in 2014. A complementary topographic dataset was acquired at the end of season 1 through the application of structure from motion with multi-view stereo (SfM-MVS) photogrammetry to a set of aerial photographs acquired from an unmanned aerial vehicle (UAV). Three-dimensional cloud-to-cloud differencing was undertaken using the Multiscale Model to Model Cloud Comparison (M3C2) algorithm. DEM differencing revealed net uplift and lateral movement of the moraine crests within season 1 (mean uplift  ~ 0.10 m) and surface lowering of a similar magnitude in some inter-moraine depressions and close to the current ice margin, although we are unable to validate the latter. Our results indicate net uplift across the site between seasons 1 and 2 (mean 0.07 m). This research demonstrates that it is possible to detect dynamic surface topographical change across glacial moraines over short (annual to intra-annual) timescales through the acquisition and differencing of fine-resolution topographic datasets. Such data offer new opportunities to understand the process linkages between surface ablation, ice flow and debris supply within moraine ice.

scholarly journals Derivation of Three-Dimensional Displacement Vectors from Multi-Temporal Long-Range Terrestrial Laser Scanning at the Reissenschuh Landslide (Tyrol, Austria)

2018 ◽  
Vol 10 (11) ◽  
pp. 1688 ◽  
Author(s):  
Jan Pfeiffer ◽  
Thomas Zieher ◽  
Magnus Bremer ◽  
Volker Wichmann ◽  
Martin Rutzinger
Keyword(s):  
Long Range ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Point Clouds ◽  
Satellite System ◽  
Image Correlation ◽  
Mountain Areas ◽  
Icp Algorithm ◽  
Displacement Vectors ◽  
Multi Temporal

Deep-seated gravitational slope deformations (DSGSDs) endanger settlements and infrastructure in mountain areas all over the world. To prevent disastrous events, their activity needs to be continuously monitored. In this paper, the movement of the Reissenschuh DSGSD in the Schmirn valley (Tyrol, Austria) is quantified based on point clouds acquired with a Riegl VZ®-6000 long-range laser scanner in 2016 and 2017. Geomorphological features (e.g., block edges, terrain ridges, scarps) travelling on top of the landslide are extracted from the acquired point clouds using morphometric attributes based on locally computed eigenvectors and -values. The corresponding representations of the extracted features in the multi-temporal data are exploited to derive 3D displacement vectors based on a workflow exploiting the iterative closest point (ICP) algorithm. The subsequent analysis reveals spatial patterns of landslide movement with mean displacements in the order of 0.62 ma − 1 , corresponding well with measurements at characteristic points using a differential global navigation satellite system (DGNSS). The results are also compared to those derived from a modified version of the well-known image correlation (IMCORR) method using shaded reliefs of the derived digital terrain models. The applied extended ICP algorithm outperforms the raster-based method particularly in areas with predominantly vertical movement.

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