Using remote sensing to track resilience of subtropical rainforests against fires and tropical cyclones
type: CreativeWork
description: The large-scale restoration of tropical and subtropical rainforests is crucial for mitigating climate change and biodiversity loss. Disturbances such as fire and wind potentially undermine efforts to restore degraded landscapes, interacting with the existing vegetation and background topography to produce complex patterns of damage. It is therefore crucial for us to understand these interactions and study the factors that contribute to disturbance resilience. Rapid developments in the field of remote sensing have provided new tools to study forest-disturbance dynamics across unprecedented spatiotemporal scales. In this thesis, a range of high-resolution remote sensing products, including aerial imagery, satellite multispectral imagery, and airborne LiDAR scans, were used to evaluate how fires and tropical cyclones have affected vegetation in wet subtropical Hong Kong. Chapter 1 provides an overview of how forest disturbances interact with restoration ecology. It then describes the vegetation history of Hong Kong, highlighting how the region represents an interesting case study as a long-running restoration project over highly degraded landscapes in the wet tropics. Chapter 2 reconstructs the fire history of Hong Kong using a 34-year Landsat imagery time series. Burn area detection in the wet tropics and subtropics is challenging due to high cloud cover and rapid revegetation of burn areas. A pipeline was developed to process hundreds of satellite multispectral images and accurately map out thousands of burnt areas. The pipeline additionally dated every detected burn area polygon and estimated burn severity for pixels in the burn area. The final product is the first of its kind in wet tropical Asia. Chapter 3 proceeds to use this burn area and severity time series to study fire-vegetation feedbacks in Hong Kong. When early successional vegetation is more fire susceptible than late-successional closed-canopy forests, positive fire-vegetation feedbacks are created. The…
abstract: The large-scale restoration of tropical and subtropical rainforests is crucial for mitigating climate change and biodiversity loss. Disturbances such as fire and wind potentially undermine efforts to restore degraded landscapes, interacting with the existing vegetation and background topography to produce complex patterns of damage. It is therefore crucial for us to understand these interactions and study the factors that contribute to disturbance resilience. Rapid developments in the field of remote sensing have provided new tools to study forest-disturbance dynamics across unprecedented spatiotemporal scales. In this thesis, a range of high-resolution remote sensing products, including aerial imagery, satellite multispectral imagery, and airborne LiDAR scans, were used to evaluate how fires and tropical cyclones have affected vegetation in wet subtropical Hong Kong. Chapter 1 provides an overview of how forest disturbances interact with restoration ecology. It then describes the vegetation history of Hong Kong, highlighting how the region represents an interesting case study as a long-running restoration project over highly degraded landscapes in the wet tropics. Chapter 2 reconstructs the fire history of Hong Kong using a 34-year Landsat imagery time series. Burn area detection in the wet tropics and subtropics is challenging due to high cloud cover and rapid revegetation of burn areas. A pipeline was developed to process hundreds of satellite multispectral images and accurately map out thousands of burnt areas. The pipeline additionally dated every detected burn area polygon and estimated burn severity for pixels in the burn area. The final product is the first of its kind in wet tropical Asia. Chapter 3 proceeds to use this burn area and severity time series to study fire-vegetation feedbacks in Hong Kong. When early successional vegetation is more fire susceptible than late-successional closed-canopy forests, positive fire-vegetation feedbacks are created. The…
author: Chan, Aland HY
language: eng
keywords: fire, forest disturbance, forest ecology, forest restoration, remote sensing, subtropical rainforest, tropical cyclones, wind
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/ac8de880-6a00-400a-bf63-3899291d2927/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2023-09-30
date modified: 2026-07-22T22:23:59Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.108031