Quantitative Analysis of Forest Fires in Southeastern Australia Using SAR Data

Abstract

Prescribed burning is a common strategy for minimizing forest fire risk. Fire is introduced under specific environmental conditions, with explicit duration, intensity, and rate of spread. Such conditions deviate from those encountered during the fire season. Prescribed burns mostly affect surface fuels and understory vegetation, an outcome markedly different when compared to wildfires. Data on prescribed burning are crucial for evaluating whether land management targets have been reached. This research developed a methodology to quantify the effects of prescribed burns using multi-temporal Sentinel-1 Synthetic Aperture Radar (SAR) imagery in the forests of southeastern Australia. C-band SAR datasets were specifically used to statistically explore changes in radar backscatter coefficients with the intensity of prescribed burns. Two modeling approaches based on pre- and post-fire ratios were applied for evaluating prescribed burn impacts. The effects of prescribed burns were documented with an overall accuracy of 82.3% using cross-polarized backscatter (VH) SAR data under dry conditions. The VV polarization indicated some potential to detect burned areas under wet conditions. The findings in this study indicate that the C-band SAR backscatter coefficient has the potential to evaluate the effectiveness of prescribed burns due to its sensitivity to changes in vegetation structure.

Assessing Burned Areas in Wildfires and Prescribed Fires with Spectral Indices and SAR Images in the Margalla Hills of Pakistan

“…Wildfires are a common natural occurrence in many environments and constitute a vital component for their management. However, fires of high severity that cause devasting impacts over large areas have recently been documented, notably in the United States of America, the Mediterranean region, Australia, and Pakistan [1][2][3][4][5], bringing into question the effectiveness of current management practices, as these severe wildfires lead to an undesirable alteration and degradation of the landscape [6]. Many variables influence the severity of a fire, including elevation, slope and aspect [7], weather and climatic conditions [8], the structural characteristics of the forest, such as the density of trees and their diameter [9], and the history of fires in the area [10].…”

“…The mapping of burned areas using SAR images relies on changes in the backscattering of the radar signal, which varies depending of the severity of the fire [3,22]. C-band SAR data have previously been used to investigate the extent of burned areas subsequent to fires in Australia and California, and it was found that the vertical horizontal (VH) polarization responded well to the occurrence of fires [3,22]. Other studies have also found that SAR imagery allowed for the detection and extent of burn scars in the landscape [25][26][27][28].…”

Monitoring of Land Use–Land Cover Change and Potential Causal Factors of Climate Change in Jhelum District, Punjab, Pakistan, through GIS and Multi-Temporal Satellite Data

“…The district has the world's second largest salt mine (Khewra salt mine), which covers an area of 2.268 million acres [54]. People of the area have diverse modes of lifestyles, beliefs, and traditions [56]. Some typical landscapes are shown in Figure 2.…”

A Synthesis of Spatial Forest Assessment Studies Using Remote Sensing Data and Techniques in Pakistan

“…Appropriate classification techniques are fundamentally essential to generate reliable forest maps [27]. The classification methods were divided into supervised image classification, unsupervised image classification, and manual and calibration categories.…”