because the MSI data is sensitive to changes in the
chlorophyll content of vegetation, which is typically
reduced in areas that have been burned. In general,
the accuracy of burned area mapping increases with
higher spatial resolution data. Using a lower spatial
resolution image, such as the 20 m spatial resolution
of Sentinel-2 data, may result in less accurate burned
area maps.
In the context of identifying burn areas,
Normalised Burn Ratio (NBR), and Normalised
Difference Moisture Index (NDMI) are among the
indices used in the context of determining burn
regions; each has certain advantages and
disadvantages. Phua et.al (2007) found that NBR is
especially good at identifying burn intensity and
defining burn scars. In dry conditions or when
attempting to distinguish between different kinds of
vegetation, NDMI may be less effective. However, it
is useful for determining the moisture level of
vegetation, which can indirectly suggest disease
susceptibility or recovery.
In tropical rainforests, burned areas may fade
within a few weeks as fresh foliage grows. Some
satellites can detect actively burning places, but may
not detect the entire charred area due to cloud cover
or delays in satellite images. Thus, SAR could serve
as an alternative data source of information since
radar sensors can image day and night, and are
capable of penetrating clouds, smoke, and smog.
Further, SAR is sensitive to changes in vegetation
structure and soil moisture following wildfire
(Bourgeau-Chavez et al., 2007). These characteristics
give SAR unique advantages in monitoring on-going
forest fire event.
Tanase, Mihai A., et al (2010) has analyzed SAR
data at X-, C-, and L-bands to investigate the
relationship between backscatter and forest focusing
on both HH and VV polarizations as well as on cross
polarized (HV). Results obtained in Spain highlighted
that for X- and C-bands, the copolarized (HH and
VV) backscatter increased with burn severity, in
detail: 1) for all frequencies, the cross polarized (HV)
decreased with burn severity; 2) C- and L-bands
cross-polarized backscatter showed better potential
for burn severity; and 3) the small dynamic range
observed for X-band data could prevent its use in
vegetation affected by fires.
Gaveau, D., Descals, A., Salim, M., Sheil, D., &
Sloan, S. (2021) present new and validated 2019
burned-area estimates for Indonesia using a time
series of the atmospherically corrected surface
reflectance multispectral images (level 2A product)
taken by the Sentinel-2A and B satellites. The
frequency–area distribution of the Sentinel-2 burn
scars follows the apparent fractal-like power law or
Pareto pattern often reported in other fire studies,
suggesting good detection over several magnitudes of
scale with 97.9% accuracy.
This research aims are to assess the effectiveness
of both Sentinel-1 SAR and Sentinel-2 optical time
series images in improving the frequency and
precision of burn area progression mapping in
peatland regions. Various approaches for optical and
SAR will be suggested to monitor the size of the
burned area in near real-time.
2 MATERIAL AND METHODS
The primary objective of the suggested methodology
is to utilise image differencing techniques to detect
burned areas in the Binsuluk Forest Reserve through
optical and SAR imagery, hence assessing the
evolution of fire in the affected region. The forest
reserve boundaries provided by the Sabah Forestry
Department is essential for identifying the source of
fire and consistently calculating the area of land
destroyed. Ultimately, we examined the impact of the
fires on the current protective forest reserve.
Figure 1: Workflow of Burned Area Mapping.
2.1 Area of Interest
The research was carried out in Binsuluk Forest
Reserve which is a protected forest reserve on the
Klias Peninsula, in Beaufort District of Interior
Active fire data collection: Hotspot data
analysis to identify location and date of fire
Overlaying with Forest
Reserve Boundary
Sentinel-1 and Sentinel 2 data
collection
Develop techniques of
burned area mapping
using SAR
(Backscatter
ratioVH/VV)Sentinel-
1
MSI Index: Normalize
Burn Ratio (NBR) and
Normalized Different
Moisture Index (NDMI)
Field Verification
Burned Area Map and Trend of
Burned Area Progression