Characterizing Rice Residue Burning and Associated
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ABSTRACT Title of dissertation: CHARACTERIZING RICE RESIDUE BURNING AND ASSOCIATED EMISSIONS IN VIETNAM USING A REMOTE SENSING AND FIELD- BASED APPROACH Kristofer Lasko, Doctor of Philosophy, 2018 Dissertation directed by: Christopher Justice, Chair and Professor, Department of Geographical Sciences Agricultural residue burning, practiced in croplands throughout the world, adversely impacts public health and regional air quality. Monitoring and quantifying agricultural residue burning with remote sensing alone is difficult due to lack of field data, hazy conditions obstructing satellite remote sensing imagery, small field sizes, and active field management. This dissertation highlights the uncertainties, discrepancies, and underestimation of agricultural residue burning emissions in a small-holder agriculturalist region, while also developing methods for improved bottom-up quantification of residue burning and associated emissions impacts, by employing a field and remote sensing- based approach. The underestimation in biomass burning emissions from rice residue, the fibrous plant material left in the field after harvest and subjected to burning, represents the starting point for this research, which is conducted in a small-holder agricultural landscape of Vietnam. This dissertation quantifies improved bottom-up air pollution emissions estimates through refinements to each component of the fine-particulate matter emissions equation, including the use of synthetic aperture radar timeseries to explore rice land area variation between different datasets and for date of burn estimates, development of a new field method to estimate both rice straw and stubble biomass, and also improvements to emissions quantification through the use of burning practice specific emission factors and combustion factors. Moreover, the relative contribution of residue burning emissions to combustion sources was quantified, demonstrating emissions are higher than previously estimated, increasing the importance for mitigation. The dissertation further explored air pollution impacts from rice residue burning in Hanoi, Vietnam through trajectory modelling and synoptic meteorology patterns, as well as timeseries of satellite air pollution and reanalysis datasets. The results highlight the inherent difficulty to capture air pollution impacts in the region, especially attributed to cloud cover obstructing optical satellite observations of episodic biomass burning. Overall, this dissertation found that a prominent satellite-based emissions dataset vastly underestimates emissions from rice residue burning. Recommendations for future work highlight the importance for these datasets to account for crop and burning practice specific emission factors for improved emissions estimates, which are useful to more accurately highlight the importance of reducing emissions from residue burning to alleviate air quality issues. CHARACTERIZING RICE RESIDUE BURNING AND ASSOCIATED EMISSIONS IN VIETNAM USING A REMOTE SENSING AND FIELD-BASED APPROACH by Kristofer Lasko Dissertation submitted to the Faculty of the Graduate School of the University of Maryland, College Park in partial fulfillment Of the requirements for the degree of Doctor of Philosophy 2018 Advisory Committee: Professor Christopher Justice, Chair Professor Krishna Vadrevu, Co-Chair Professor Ivan Csiszar Professor Louis Giglio Professor Michael Gollner Professor Matthew Hansen © Copyright by Kristofer Lasko 2018 Foreword Chapters 2-5 contain jointly authored work in which Kristofer Lasko is the primary author. Conceptualization, methods development, processing, analysis, and manuscript writing was led by Kristofer Lasko with contributions from the other co-authors named in each corresponding chapter. ii Acknowledgements I first thank my Co-Advisor Dr. Krishna Vadrevu. Thanks for taking me on initially as an intern during my undergraduate degree where I got my first research experience. At that time, I did not realize I would continue on to a master’s degree, let alone a PhD! Thanks for providing me the opportunity to have a great research experience to jump-start my graduate education, coupled with guidance on how to work effectively towards a goal and career. I also thank my advisor, Dr. Christopher Justice, for providing support, networking connections, and broad guidance on my PhD topic, as well as helping me stay on track by focusing on the most important parts of my research. I am grateful for the mentorship, guidance, and critical analysis provided by my remaining committee members, each of whom is a leading expert in their sub-discipline: Ivan Csiszar, Louis Giglio, Matthew Hansen, and Michael Gollner. I am thankful for the chance to work with the NASA Land Cover / Land Use Change program as a research assistant and meeting coordinator under leadership from Dr. Garik Gutman. I’m also grateful for the opportunities to travel abroad to conduct research, give training sessions, and network –a result of funding from UMD, START, NAS LCLUC, and the SMART scholarship program. I also thank William Salas and Nathan Torbick of Applied Geosolutions LLC for taking time to teach me about SAR in relation to rice mapping. Lastly, the support of scientists from Vietnam National University was critical, especially for field logistics, I specifically thank Thanh Thi Nhat Nguyen, Hung Quang Bui, Vinh Tuan Tran, Chuc Duc Man, and Ha Pham Van, and Pham Van Cu. iii I am thankful to my office colleagues and 2014 PhD cohort for assistance, advice, troubleshooting as well as camaraderie helping to alleviate the stress of the PhD program. I will miss you all very much! Lastly, I am eternally thankful to my family, including my parents for their support during this stressful, but incredibly rewarding PhD journey. Lastly, thank you to my wife, Nicole, for all that you’ve done. iv Table of Contents Foreword ......................................................................................................................................... ii Acknowledgements ....................................................................................................................... iii Table of Contents ........................................................................................................................... v Chapter 1: Introduction ................................................................................................................ 1 1.1 Background and motivation of the study ......................................................................... 1 1.2 Purpose of the study ......................................................................................................... 4 1.3 Research questions and design ......................................................................................... 5 1.3.1 Design of the study ................................................................................................... 5 1.3.2 Research objectives .................................................................................................. 6 1.4 Significance of study area ................................................................................................ 8 1.5 Organization of the study ............................................................................................... 10 1.6 References ...................................................................................................................... 12 Chapter 2: Mapping and characterizing paddy rice with Sentinel-1A at varying spatial scales and polarizations in Hanoi, Vietnam ............................................................................... 15 2.1 Abstract ................................................................................................................................ 15 2.2 Introduction .......................................................................................................................... 16 2.3 Study area and datasets ........................................................................................................ 19 2.3.1 Study area ..................................................................................................................... 19 2.3.2 Satellite data ................................................................................................................. 20 2.3.3 Training and validation data ........................................................................................ 22 2.3 Methodology ........................................................................................................................ 23 2.3.1 Double and single crop rice mapping ........................................................................... 24 2.3.2 Accuracy Assessment .................................................................................................... 25 2.3.3 Spatial Analysis ............................................................................................................. 26 2.3.4 Rice phenology ............................................................................................................. 28 2.4 Results .................................................................................................................................. 28 2.4.1 Mapped area variation ................................................................................................. 28 2.4.2 Accuracy assessment and areal adjustment .................................................................. 29 2.4.3