Sedimentation Dynamics of the Cagayan De Oro River Catchment and the Implications for Its Coastal Marine Environments
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The University of Notre Dame Australia ResearchOnline@ND Theses 2017 Sedimentation dynamics of the Cagayan de Oro river catchment and the implications for its coastal marine environments Mars P. Tan The University of Notre Dame Australia Follow this and additional works at: https://researchonline.nd.edu.au/theses Part of the Environmental Sciences Commons COMMONWEALTH OF AUSTRALIA Copyright Regulations 1969 WARNING The material in this communication may be subject to copyright under the Act. Any further copying or communication of this material by you may be the subject of copyright protection under the Act. Do not remove this notice. Publication Details Tan, M. P. (2017). Sedimentation dynamics of the Cagayan de Oro river catchment and the implications for its coastal marine environments (Doctor of Philosophy Science). University of Notre Dame Australia. https://researchonline.nd.edu.au/theses/165 This dissertation/thesis is brought to you by ResearchOnline@ND. It has been accepted for inclusion in Theses by an authorized administrator of ResearchOnline@ND. For more information, please contact [email protected]. Sedimentation Dynamics of the Cagayan de Oro River Catchment and the implications for its coastal marine environments Mars Platino Tan, S.J. School of Arts and Sciences, University of Notre Dame Australia Supervising Professors Dr Rene Rollon (University of the Philipines) Dr Tolentino Moya (University of the Philippines) A/Prof Dylan Korczynskyj (University of Notre Dame Australia) This thesis is submitted in fulfillment of the requirements for the award of the degree of Doctor of Philosophy in Environmental Science November 2017 Acknowledgements The completion of this thesis would not have been possible without the assistance of many generous and kind individuals and institutions both in the Philippines and in Western Australia. Unfortunately, it is impossible to remember all of them. First and foremost, my sincere gratitude and appreciation to my academic supervisors, Dr Rene Rollon and Dr Tolentino Moya of the University of the Philippines, whose expertise in and passion for science research have guided me well through the complexities of my thesis until its completion; to Dr Dylan Korczynskyj of the University of Notre Dame Australia, whose professional mentorship from beginning to end has provided me with the key support from writing to logistics; to Dr Olive Cabrera of the University who assisted me in the Physical Oceanography part of my study; to Dr Erik Paling of the University of Western Australia, for his scientific critiques that no doubt have improved different aspects of my study; to Dr Michael O’Leary of Curtin University, who mentored me in the initial phase of my study; to Mr. Mark Sabines, of Xavier University (Philippines), who graciously tutored me on the intricacies of SWAT modeling; to Dr Caroline Jaraula of Curtin University, for her helpful inputs in my thesis proposal; and to Dr Augustine Doronila of the University of Melbourne, who helped me find my way to the University of Notre Dame Australia. In the collection, analyses, and presentations of the massive amount of both field and secondary data, I am truly thankful to James Borcillo, my indefatigable research assistant and companion, who took on all kinds of odd jobs for the research work; to the present and former staff and volunteers of the McKeough Marine Center (XU), namely, Czarmayne Escoro, Marriane Macapilet, Ria Ramos, Janice Rivera, Julie Acero, Fra-and Quimpo, Jun Aranzo, Daniel Linog, Warwin Sabasaje, Friday Atilano, and Ariel Talavera; to the former Director of the Engineering Resource Center (XU), the ever reliable research colleague and friend, Engr. Dexter Lo, and his staff and volunteers, namely, Mr Jan Taat, Engr. Gerry Apor, Shaira Baang, Jeff Vallente, Meldy Comandante, and Rengie Bagares; to Dr Ester Raagas of the Kinaadman Research Center (XU), for the statistical work; and to Janna Batillo, Camille Bollozos, and Menche Lazarte, for their help in modeling works (SWAT & DELFT3D). For the facilities and equipment, I sincerely thank the Chairs/Directors of the McKeough Marine Center, the Biology Department, the Geo-Informatics System Center, and the Engineering Resource Center of Xavier University I truly appreciate the enormous help and support of several people from the University of Notre Dame Australia: Dr Marc Fellman, Director of the Research Office; Ms Lorraine Mayhew, Administrative Assistant; and Dr Julia Alessandrini and Dr Kate Howell, former and present Higher Degree Research Education Coordinators, respectively. Several persons from the University have given me support in various ways: Ms. Jackie Stevens of the Notre Dame Library; Ms Victoria Li of the International Students Administration; Dr Sarah McGann, Dean of the School of Arts and Sciences and her academic colleagues, namely, Dr Angeline O’Neill and Prof Chris Wortham; Richard King of the Academic and Enabling iii Support Office; and the staff of the University library. Also, my sincere gratitude to Prof. Peta Sanderson, Pro Vice-Chancelor Research and International, for her full support and encouragement. Back in the Philippines, various local communities and government institutions have accommodated me to conduct on-site field work and have provided me with valuable secondary data: Barangays Macabalan and Bonbon; the Parish of Talakag; the communities of Miarayon, Nangka, Taguanao, and Tikalaan in Bukidnon; the Bureau of Soils and Water Management; the Cagayan de Oro City Planning and Development Office; the Cagayan de Oro River Basin Management Council; the Department of Environment and Natural Resources-River Basin Control Office; the Department of Public Works and Highways- Region 10; the Philippines Atmospheric, Geophysical and Astronomical Services Administration in Cagayan de Oro City and in Malaybalay City, the Macajalar Bay Development Alliance, and the Manila Observatory in the Ateneo de Manila University. Several people have played key roles behind the scenes to enable me to do my writing and to complete the thesis, for which I most grateful: To Fr Roberto Yap, SJ, President of Xavier University, who approved my study leave and, in addition to the herculean task of running the University, generously “held the fort” for me as Acting Rector of the Jesuit Community in the Xavier University; to his predecessor, Fr Jose Ramon Villarin, SJ, President of the Ateneo de Manila University, who likewise served as the superior of the community, in my absence; to my Provincial Superiors, Fr Jose Cecilio Magadia who approved my studies abroad and to Fr Antonio Moreno, SJ, for his encouragement and his kind understanding to free me from all regular ministries and duties so I could steadily focus on my writing; to all my Jesuit brethren at Xavier University and the Loyola House of Studies for substituting for me in various tasks and for their prayers. In the editing of my thesis, I truly appreciate the help of my brother Jesuits, Fr. Louis Catalan, Fr Manuel Francisco, Fr Eric Genilo, Fr. Gabriel Gonzalez, Fr Robert Rivera, Fr Albert Alejo, and Fr Walter Ysaac. I also thank the staff of the Loyola School of Theology Library, where I spent my daily routine of thesis work for many months. Writing the thesis has been made bearable because of my friendships with several individuals who, in their own ways, have provided me much help and inspiration: My ever generous host family in Perth, Dr Hector and Ms Aurora Divinagracia and their son, Gerry, who took me in as part of the family; my second Jesuit family in Nedlands, Fr Joseph Sobb, Fr John Prendiville, and Fr Hari Suparwito; the community of All Saints Catholic Chapel in Perth, particularly the late Fr Tiziano Bogoni; Theresa Pike and her family; Margaret de Ornelas and Frances Dennis; and Msgr. Michael Keating of the St Mary’s Cathedral. In the Philippines, I benefited much from the invaluable assistance of my academic colleagues and friends, Dr Libby Abesamis, Dr Hilly Quiaoit, Ms Gertrude Garcia, Ms Elaine Villanuz, and Ms Elizabeth Enerio. For the scholarship grants and funding support, I am indebted and truly grateful to the Government of Australia, the University of Notre Dame Australia, Xavier University, and the Philippine Province of the Society of Jesus. iv Last but not the least in this long list, are the members of my own family, from whom I found loving inspiration and drew much encouragement throughout the long arduous yet fulfilling journey towards the completion of my PhD thesis: My father, Oscar (deceased) and my mother, Lucia (deceased); my sisters Corazon, Olivita, Brigide and Ma. Leizel; my brother Donderex; and my beautiful nieces, Dea Zelene and Deance Jaira. Finally, I thank the Almighty God who has sustained me during my lowest moments, guided me through the crucial decisions I had to make, awakened in me confidence in myself and in the goodness of others, and kept me focused on the ultimate meaning of my study. Ad Majorem Dei Gloriam v Abstract Declines in coastal environment condition can often be attributed to land-based activities in the uplands. This may be the case in some parts of Macajalar Bay, where river plume is observed almost daily. This present study aims to demonstrate the erosion-sedimentation process along the Cagayan de Oro River Catchment to its river mouth, and its implication for the marine coastal habitats. Highlighted in the study are the various natural factors that have influenced the erosion-sedimentation process: its volume; direction; and effects on the coastal habitats. In the uplands, to account for the influence of catchment spatial heterogeneity and local rainfall on run-off rates and sediment yield, the Soil Water Assessment Tool (SWAT) model was employed. The model predicted high (15 > 50 t/ha/yr) to very high sediment yields (>50 t/ha/yr) in a few sub-catchments and slight to moderate yields (0 > 15 t/ha/yr) in most sub- catchments. However, during heavy and prolonged rainfall events, a number of sub- catchments became highly prone to erosion, due to existing large cultivated lands and very steep slopes.