Document Type

Dissertation - Open Access

Award Date

2022

Degree Name

Doctor of Philosophy (PhD)

Department / School

Geography and Geospatial Sciences

First Advisor

Xiaoyang Zhang

Keywords

Biomass burning, Climate change, Fire emission, Land use change, Smoke aerosol

Abstract

Indonesia has experienced frequent fires since the 1970s due to large-scale peatland conversion and extensive drainage for agricultural development. Fire emissions released from these fires have led to Indonesia being the world’s 3rd largest emitter of greenhouse gases in certain years. Given that fire emissions severely affect climate, weather, and the human environment, numerous approaches have been developed to estimate fire emissions. However, existing emission estimates differ largely by a factor of four in this tropical country because of frequent cloud interferences and low-temperature smoldering fires. Therefore, this dissertation aims to improve the quantification of Indonesian fire emissions through enhanced parameters of smoke aerosol emission coefficient (Ce) and fire radiative energy (FRE: time-integrated fire radiative power (FRP)) within the framework of FRPbased approach, as well as to investigate the drainage canal and peatland degradation impacts on fire emissions using satellite observations. Specifically, Chapter 2 provides a novel algorithm to derive Ce values for different land cover types using Moderate Resolution Imaging Spectroradiometers (MODIS) active fire and aerosol optical depth (AOD) products. This study demonstrates that Ce value varies with land cover types, with a larger value in peatlands than in non-peatlands. Chapter 3 develops a new algorithm to improve the estimation of fire emissions using observations from Advanced Himawari Imager (AHI) onboard geostationary satellite and Visible Infrared Imaging Radiometer Suite (VIIRS) onboard polar-orbiting satellite. It enhances FRE calculation using the reconstructed diurnal FRP cycle by fusing FRP retrievals from high temporal-resolution AHI with those from high spatial-resolution VIIRS. This chapter also improves Ce retrievals using VIIRS active fire and aerosol observations. The fire emission estimates from diurnal FRP and Ce show a high quality according to its significant correlation with an independent reference dataset derived from MODIS AOD. The estimated fire emissions over the study period from 2015 to 2020 reveal that the greatest fire emissions occurred during the strong 2015 El Niño event. Most of these emissions were released from Kalimantan and Sumatra islands, particularly their peatland areas. Chapter 4 investigates the impacts of drainage-related water level and peatland degradation on fire emissions. The results suggest that water level decrease leads to an effect of exponential increase of fire emissions, and vice versa. Besides, this effect is doubled in peatlands relative to non-peatlands because the underlying peat soils become combustion fuels in peatlands if water levels are reduced significantly. Chapter 5 summarizes the research and presents some recommendations for future research. Overall, this dissertation paves the way for improved estimation of tropical biomass burning emissions and supports the Indonesian government’s recent peatland restoration policies.

Number of Pages

217

Publisher

South Dakota State University

Available for download on Thursday, December 15, 2022

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Rights Statement

In Copyright