A time-integrated MODIS burn severity assessment using the multi-temporal differenced normalized burn ratio (dNBRMT)

<p><strong>Abstract.</strong> Wildfire has a strong effect on both land use and land cover so that every year, thousands of hectares of forests, farms, and urban infrastructure are destroyed. Mapping and estimation of damages are crucial for planning and decision making. The aim of this study is classification and mapping burn severity using multi-temporal Landsat data and well-known burn severity indices including Normalized Burn Ratio (NBR) and Burned Area Index (BAI) calculated for pre- and post- Landsat 8 images. Subtracted images such as dNBR (Difference Normalized Burn Ratio), RBR (Relativized Burn Ratio) and dBAI (Difference Burned Area Index) were produced on the bases of indices as classification input. Among classification methods, the fuzzy supervised classification was utilized with three classes. The result shows the strong performance of the Fuzzy Logic system (FLS) in the detection of the area with the limited number of training data so that the average accuracy of the classes is 85%; plus, from the human logic perspective, the result was meaningful so that recognition of the features and changes visually were understandable.</p>

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Quantificação da Severidade das Queimadas e da Perda de Sequestro Florestal de Carbono em Unidades de Conservação do Distrito Federal (Measurement of Severity of Fires and Loss of Carbon Forest sink in the Conservation Units at Distrito Federal)

Revista Brasileira de Geografia Física ◽

10.26848/rbgf.v9.1.p250-264 ◽

2016 ◽

Vol 9 (1) ◽

pp. 250

Author(s):

Débora Teobaldo ◽

Gustavo Macedo de Mello Baptista

Keyword(s):

Carbon Sink ◽

Severity Index ◽

Burn Severity ◽

Conservation Units ◽

Differenced Normalized Burn Ratio ◽

Before And After ◽

Distrito Federal ◽

Para Determinar ◽

Normalized Burn Ratio ◽

The Relationship

O objetivo desse trabalho foi avaliar o grau de severidade das queimadas e da perda do sequestro de carbono nas principais Unidades de Conservação do Distrito Federal nos anos de 2010 e 2011. Para determinar o grau de severidade utilizou-se índices espectrais antes e depois da queimada, como o índice de queimada por razão normalizada (NBR) e o índice relativo diferenciado de queimada por razão normalizada (RdNBR). O sequestro de carbono perdido pela queimada foi comparado antes, depois da queimada e na rebrota pelo índice espectral CO2flux. A relação entre a severidade e o sequestro de carbono também foi determinada por meio das imagens de pré-fogo, pós-fogo e da rebrota e a comparação temporal do CO2flux. As regressões obtidas para o ano de 2010 foram bastante de acordo com o esperado, com baixa relação antes da queimada, alta após, e menor na rebrota. Já para 2011, como ocorreram queimadas ao longo de todo o período, não foi possível verificar relações favoráveis. A B S T R A C T The aim of this study was to assess the burn severity and carbon sink in the Conservation Units at Distrito Federal in the 2010 and 2011. For the burn severity index was used to quantify biomass before and after burning, such as a Normalized Burn Ratio - NBR and relative differenced Normalized Burn Ratio - RdNBR indices. Carbon sink lost by the burning was compared before and after fire by regrowth CO2flux spectral index. The relationship between the burn severity and carbon sink were also made by means the pre, post-fire and regrowth images, and temporal comparison of CO2flux. The regressions obtained for the 2010 were largely in agreement with expectations, with a low pre-fire, after high and low in regrowth. Already in 2011, as fires occurred throughout the period, it was not possible to verify favorable relationships. Keywords: Biomass, burn severity, RdNBR, carbon sink, CO2flux.

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LANDSAT-BASED DETECTION AND SEVERITY ANALYSIS OF BURNED SUGARCANE PLOTS IN TARLAC, PHILIPPINES USING DIFFERENCED NORMALIZED BURN RATIO (dNBR)

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-4-w1-173-2016 ◽

2016 ◽

Vol XLII-4/W1 ◽

pp. 173-179 ◽

Cited By ~ 2

Author(s):

A. B. Baloloy ◽

A. C. Blanco ◽

B. S. Gana ◽

R. C. Sta. Ana ◽

L. C. Olalia

Keyword(s):

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

The Philippines ◽

Local Economy ◽

Burn Severity ◽

Burned Area ◽

Landsat 8 ◽

Potential Yield ◽

Differenced Normalized Burn Ratio ◽

Normalized Burn Ratio

The Philippines has a booming sugarcane industry contributing about PHP 70 billion annually to the local economy through raw sugar, molasses and bioethanol production (SRA, 2012). Sugarcane planters adapt different farm practices in cultivating sugarcane, one of which is cane burning to eliminate unwanted plant material and facilitate easier harvest. Information on burned sugarcane extent is significant in yield estimation models to calculate total sugar lost during harvest. Pre-harvest burning can lessen sucrose by 2.7% - 5% of the potential yield (Gomez, et al 2006; Hiranyavasit, 2016). This study employs a method for detecting burn sugarcane area and determining burn severity through Differenced Normalized Burn Ratio (dNBR) using Landsat 8 Images acquired during the late milling season in Tarlac, Philippines. Total burned area was computed per burn severity based on pre-fire and post-fire images. Results show that 75.38% of the total sugarcane fields in Tarlac were burned with post-fire regrowth; 16.61% were recently burned; and only 8.01% were unburned. The monthly dNBR for February to March generated the largest area with low severity burn (1,436 ha) and high severity burn (31.14 ha) due to pre-harvest burning. Post-fire regrowth is highest in April to May when previously burned areas were already replanted with sugarcane. The maximum dNBR of the entire late milling season (February to May) recorded larger extent of areas with high and low post-fire regrowth compared to areas with low, moderate and high burn severity. Normalized Difference Vegetation Index (NDVI) was used to analyse vegetation dynamics between the burn severity classes. Significant positive correlation, rho = 0.99, was observed between dNBR and dNDVI at 5% level (p = 0.004). An accuracy of 89.03% was calculated for the Landsat-derived NBR validated using actual mill data for crop year 2015-2016.

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1984–2010 trends in fire burn severity and area for the conterminous US

International Journal of Wildland Fire ◽

10.1071/wf15039 ◽

2016 ◽

Vol 25 (4) ◽

pp. 413 ◽

Cited By ~ 36

Author(s):

Joshua J. Picotte ◽

Birgit Peterson ◽

Gretchen Meier ◽

Stephen M. Howard

Keyword(s):

Time Series ◽

Vegetation Classification ◽

Cumulative Distribution ◽

Burn Severity ◽

Burned Area ◽

Detectable Change ◽

Historical Trends ◽

Differenced Normalized Burn Ratio ◽

Normalized Burn Ratio ◽

In Fire

Burn severity products created by the Monitoring Trends in Burn Severity (MTBS) project were used to analyse historical trends in burn severity. Using a severity metric calculated by modelling the cumulative distribution of differenced Normalized Burn Ratio (dNBR) and Relativized dNBR (RdNBR) data, we examined burn area and burn severity of 4893 historical fires (1984–2010) distributed across the conterminous US (CONUS) and mapped by MTBS. Yearly mean burn severity values (weighted by area), maximum burn severity metric values, mean area of burn, maximum burn area and total burn area were evaluated within 27 US National Vegetation Classification macrogroups. Time series assessments of burned area and severity were performed using Mann–Kendall tests. Burned area and severity varied by vegetation classification, but most vegetation groups showed no detectable change during the 1984–2010 period. Of the 27 analysed vegetation groups, trend analysis revealed burned area increased in eight, and burn severity has increased in seven. This study suggests that burned area and severity, as measured by the severity metric based on dNBR or RdNBR, have not changed substantially for most vegetation groups evaluated within CONUS.

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Evaluating the ability of the differenced Normalized Burn Ratio (dNBR) to predict ecologically significant burn severity in Alaskan boreal forests

International Journal of Wildland Fire ◽

10.1071/wf08050 ◽

2008 ◽

Vol 17 (4) ◽

pp. 490 ◽

Cited By ~ 70

Author(s):

Karen A. Murphy ◽

Joel H. Reynolds ◽

John M. Koltun

Keyword(s):

Boreal Forest ◽

Boreal Forests ◽

Burn Severity ◽

Fire Season ◽

Vegetation Composition ◽

Management Objectives ◽

Differenced Normalized Burn Ratio ◽

Normalized Burn Ratio ◽

Processing Errors ◽

The Relationship

During the 2004 fire season ~6.6 million acres (~2.7 million ha) burned across Alaska. Nearly 2 million of these were on National Wildlife Refuge System lands inaccessible from the state’s limited road system. Many fires burned through September, driven by unusually warm and dry temperatures throughout the summer. Using several fires from this season, we assessed the national burn severity methodology’s performance on refuge lands. Six fires, spanning 814 489 acres (329 613 ha), were sampled on five boreal forest refuges. In total, 347 sites were sampled for vegetation composition and ground-based burn severity estimates following the national protocols. The relationship between the differenced Normalized Burn Ratio (dNBR) and composite burn index (CBI) was unexpectedly weak (R2adjusted, 0.11–0.64). The weak relationship was not a result of data or image processing errors, nor of any biotic or abiotic confounding variable. The inconsistent results, and dNBR’s limited ability to discern the ecologically significant differences within moderate and high severity burn sites, indicate that the current methodology does not satisfy key Alaskan boreal forest management objectives.

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Atmospheric effects on the performance and threshold extrapolation of multi-temporal Landsat derived dNBR for burn severity assessment

International Journal of Applied Earth Observation and Geoinformation ◽

10.1016/j.jag.2014.04.017 ◽

2014 ◽

Vol 33 ◽

pp. 10-20 ◽

Cited By ~ 18

Author(s):

Lei Fang ◽

Jian Yang

Keyword(s):

Burn Severity ◽

Atmospheric Effects ◽

Severity Assessment ◽

Multi Temporal

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Comparison of burn severity assessments using Differenced Normalized Burn Ratio and ground data

International Journal of Wildland Fire ◽

10.1071/wf04010 ◽

2005 ◽

Vol 14 (2) ◽

pp. 189 ◽

Cited By ~ 251

Author(s):

Allison E. Cocke ◽

Peter Z. Fulé ◽

Joseph E. Crouse

Keyword(s):

Pinus Ponderosa ◽

Forest Structure ◽

Tree Mortality ◽

Fire Severity ◽

Basal Area ◽

Burn Severity ◽

Burned Areas ◽

Differenced Normalized Burn Ratio ◽

Severity Levels ◽

Normalized Burn Ratio

Burn severity can be mapped using satellite data to detect changes in forest structure and moisture content caused by fires. The 2001 Leroux fire on the Coconino National Forest, Arizona, burned over 18 pre-existing permanent 0.1 ha plots. Plots were re-measured following the fire. Landsat 7 ETM+ imagery and the Differenced Normalized Burn Ratio (ΔNBR) were used to map the fire into four severity levels immediately following the fire (July 2001) and 1 year after the fire (June 2002). Ninety-two Composite Burn Index (CBI) plots were compared to the fire severity maps. Pre- and post-fire plot measurements were also analysed according to their imagery classification. Ground measurements demonstrated differences in forest structure. Areas that were classified as severely burned on the imagery were predominantly Pinus ponderosa stands. Tree density and basal area, snag density and fine fuel accumulation were associated with severity levels. Tree mortality was not greatest in severely burned areas, indicating that the ΔNBR is comprehensive in rating burn severity by incorporating multiple forest strata. While the ΔNBR was less accurate at mapping perimeters, the method was reliable for mapping severely burned areas that may need immediate or long-term post-fire recovery.

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Assessing the potential of the differenced Normalized Burn Ratio (dNBR) for estimating burn severity in eastern Canadian boreal forests

International Journal of Wildland Fire ◽

10.1071/wf15122 ◽

2017 ◽

Vol 26 (1) ◽

pp. 32 ◽

Cited By ~ 13

Author(s):

Jonathan Boucher ◽

André Beaudoin ◽

Christian Hébert ◽

Luc Guindon ◽

Éric Bauce

Keyword(s):

Boreal Forests ◽

Black Spruce ◽

Additive Model ◽

Time Frame ◽

Burn Severity ◽

Eastern Canada ◽

Generalised Additive Model ◽

Boreal Region ◽

Differenced Normalized Burn Ratio ◽

Normalized Burn Ratio

There is considerable variation in the degree of burn severity in boreal fires. One approach that has been used to capture this variation from field and remote sensing perspectives for western Canadian boreal forests is the Composite Burn Index (CBI) and differenced Normalized Burn Ratio (dNBR). Of interest was how well these methods may perform for fires in eastern Canada. This study investigated the CBI-dNBR relationship for selected fires in the eastern boreal forests of Canada, with a view towards contributing to the generalisation of a Canada-wide model. Results for the sampled region showed no difference in the CBI-dNBR relationship between black spruce- and jack pine-dominated stands, whereas this relationship was best described by a Generalised Additive Model (GAM). The dNBR-derived maps would also be useful in support of research and post-fire management in burns outside the studied territory and time frame covered by the existing burn severity mapping system already used in this region. The Saturated growth model proposed for the western boreal region also performed well for our eastern boreal region, thus further supporting the development of a national model.

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