WATER QUALITY MODELING AND LOAD ALLOCATION IN LAM TAKHONG WATERSHED Chau Ngoc Tran A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Industrial Systems and Environmental Engineering Suranaree University of Technology Academic Year 2019 แบบจ ำลองคุณภำพน ้ำและกำรประเมินภำระของเสียในล่มุ น ้ำลำ ตะคอง นำงสำวเจ่ำ ง็อบ เจ่ำ วิทยำนิพนธ์นีเ้ ป็นส่วนหนึ่งของกำรศึกษำตำมหลกั สูตรปริญญำวิศวกรรมศำสตรดุษฎีบัณฑิต สำขำวิชำวิศวกรรมระบบอุตสำหกรรมและสิ่งแวดล้อม มหำวิทยำลัยเทคโนโลยีสุรนำรี ปีกำรศึกษำ 2562 ACKNOWLEDGEMENTS Suranaree University of Technology has been my second home for the past 4 years, this period is the meaningful and important chapter of my life when I worked the most, enjoyed the most, and grew up more and more. I will remember my whole life regarding this time. Before closing this chapter, I would like to express my deepest gratitude to all the people who have contributed to complete my PhD degree. I would first like to extend my sincere thanks to my advisor, Dr. Chatpet Yossapol for his great insights, perspectives, guidance, encouragement, and support me to develop not only an understanding of the thesis. These have been invaluable for the past four years. He always keeps an open mind in every academic discussion and I really admire his critical opinion for the research topic. This dissertation would not have been completed without his guidance and support. I would like to appreciate to my dissertation committee, including Dr. Somchai Dararatana, Assoc. Prof. Dr. Netnapid Tantemsapya, Assoc. Prof. Dr. Nares Chuersuwan, Asst. Prof. Dr. Preeyaphorn Kosa, and Dr. Apichon Watcharenwong in help, guidance, and discussion on my thesis. Besides, I would like to express my thanks to all instructors at the Environment Engineering school at SUT. I would like also to take this opportunity to thank the SUT-PhD scholarship for ASEAN countries giving me the opportunity to study in Thailand and grant scholarships for my entire course. The warmest thank to my colleagues Be Phuc, Thanh Hung, Nhan Tanh, Khanh Trinh, Dan Thanh, and other colleagues at An Giang University who shared the difficulties and supported my work while I was conducting this study. VI I would like to express my special regards to P'Chayapat Charintorn and P'Chantharus Boonmak who take care of me as a daughter and take me to go to nice places to relax, without you, my PhD life would have been very boring. I would also like to thank P'Lukjan’s family for welcoming and making me feel like family when I am away from my home. I also wish to thank all of the staff in the CIA, Pa Khun Buaby Buffa, P'Khun Narree help me during the period of this research. I also give my sincere gratitude to Kamolrat, Borano, Narudon, Yotsapon, Tharika, Oranee, Aim, Abnor, Nattapat, Supussara, Sineenad, Pimchanok, Warm for their great help during my time in SUT. Special thanks to Phatsakrit, who have helped and overcome difficulties together, in addition, his results supporting my research. Thanks to my Vietnamese friends in SUT: chi Huong, anh Vui, be Linh, Hieu, anh Doan, Danh, anh Linh, anh Trung, anh Thanh, Thu, Hai, Quynh, Trinh, chi Hang, chi Dinh for sharing good times with me which made my life in SUT more lively. And thanks to all my friends in Vietnam: me Hong Tam, co Huyen, ut Tam, co Thuy, thay Phu, chi Linh, Hong Diep, anh Hoa, Viet Huong, Nhi Ha, Bao Tram, Thuan, Que, co Thuong and my special friends for your support and sharing make me be more mature. Last but not least, I would like to send my deepest gratitude to my family: my parents, my older brother, my older sister, and my nephews for their unconditional love and support for me during my whole life. I am really lucky to have a good family who wish me the best for my life. Thanks to my brother and sister to be beside my parents to take care of my parents during my absence. Chau Ngoc Tran TABLE OF CONTENTS Page ABSTRACT (THAI) I ABSTRACT (ENGLISH) III ACKNOWLEDGMENTS V TABLE OF CONTENTS VII LIST OF TABLES XIV LIST OF FIGURES XXI LIST OF ABBREVIATIONS XXVIII CHAPTER I INTRODUCTION 1 1.1 Background and problem statement 1 1.2 Motivation of the thesis 3 1.3 Research Questions 4 1.4 Research objectives 4 1.5 Scope and limitation of the thesis 5 1.5.1 Study area 5 1.5.2 Study period 5 II LITERATURE REVIEW 7 2.1 Water quality problem of the study 7 2.2 Total maximum daily loading (TMDL) 9 VIII TABLE OF CONTENTS (Continued) Page 2.2.1 TMDL Background 9 2.2.2 Water quality targets 11 2.2.3 Loading Capacity 12 2.2.4 TMDL Reduction 13 2.3 Water quality models tool 16 2.3.1 Signature of Water Quality Models 16 2.3.2 Development of Water Quality Models 17 2.3.3 Types of existing water quality models 20 2.3.4 Comparisons of water quality models 26 2.3.5 Selection of the study 36 2.4 SWAT Model (soil and water assessment tool) 37 2.4.1 The land phase of the hydrological cycle 37 2.4.2 Routing phase of the hydrological cycle 41 2.4.3 Modeling parameterization 44 2.5 QUAL2K Model 47 2.5.1 History of model 47 2.5.2 Model inputs 48 2.5.3 Model Outputs 48 2.5.4 Model Application 49 2.6 Integrated swat model and swat model applications 49 IX TABLE OF CONTENTS (Continued) Page 2.6.1 SWAT model applications in the US and other countries 50 2.6.2 SWAT model applications in Thailand 52 2.7 QUAL2K Model applications 55 2.8 Lam Takhong basin 58 2.8.1 Characteristics 58 2.8.2 Meteorology 59 2.8.3 Pedology features 59 2.8.4 Land utilization 60 2.8.5 Population 60 2.8.6 Lam Takhong reservoir 60 2.8.7 Water quality researches in Lam Takhong 61 III METHODOLOGY 64 3.1 Working process 64 3.2 Build a watershed model of Lam Takhong basin using SWAT Model 67 3.2.1 Watershed delineation 69 3.2.2 HRU analysis 71 3.2.3 Input data 75 3.2.4 SWAT model calibration and validation 77 X TABLE OF CONTENTS (Continued) Page 3.2.5 Impact of land use change on hydrological data in 2027 and 2035 84 3.3 QUAL2K Model 86 3.3.1 Set up Qual2k model 86 3.3.2 Qual2k model calibration 99 3.3.3 Qual2k model validation 102 3.3.4 Performance measures and evaluation criteria of model 102 3.3.5 Current simulation scenarios 105 3.3.6 Future simulation scenarios 106 3.3.7 Estimating TMDL 108 IV RESULTS AND DISCUSSION 109 4.1 Hydrological modeling for Lam Takhong River using SWAT 109 4.1.1 Model calibration 109 4.1.2 Model validation 116 4.1.3 Evaluation of hydrology predictions and water yield from the subbasin contributes to streamflow 119 4.2 Water quality modeling using QUAL2K 123 XI TABLE OF CONTENTS (Continued) Page 4.2.1 Configuration of Lam Takhong River and Scenarios Description 123 4.2.2 Water quality calibration 130 4.2.3 Water quality validation 135 4.3 Contribution of pollution sources to the pollution of Lam Takhong River 139 4.3.1 TMDL and percentage of contribution from different pollution sources to the pollution of Lam Takhong River in 2019 140 4.3.2 TMDL and percentage of contribution from different pollution sources to the pollution of Lam Takhong River in future 141 4.4 Scenarios for water quality control 143 4.4.1 BOD loading reduction of point sources 143 4.4.2 BOD loading reduction of diffuse sources 148 4.4.3 Determining of TMDL reduction to meet water quality standard targets in Thailand 151 4.5 Scenarios for water quality prediction 152 4.5.1 Land use change in the Lam Takhong watershed 152 XII TABLE OF CONTENTS (Continued) Page 4.5.2 Change the outflow of wastewater treatment plants 156 4.5.3 Scenarios of water quality control by BOD discharge reduction from WWTPs 161 4.5.4 The inflow change of headwater scenarios 165 4.5.5 Change outflow and BOD load from WWTP to meet water quality standard targets in Thailand 173 4.6 Summary 179 V CONCLUSIONS AND RECOMMENDATIONS 189 5.1 Conclusions 189 5.1.1 Models application 189 5.1.2 Simulation results and water quality assessment in Lam Takhong River 190 5.1.3 The use of study results 192 5.1.4 Scholary contribution 192 5.2 Recommendations 193 5.2.1 Policy recommendation 193 5.2.2 Future research activities recommendation 194 XIII TABLE OF CONTENTS (Continued) Page REFERENCES 196 APPENDIX LIST OF PUBLICATIONS 204 BIOGRAPHY 206 LIST OF TABLES Table Page 2.1 Main surface water quality models and their versions and characteristics 19 2.2 Principal water quality models for rivers and streams 20 2.3 Water quality models for the basin scale 22 2.4 Summary of Watershed Simulation Capabilities 23 2.5 TMDL Endpoints Supported Model 27 2.6 Summary of NPS pollution models 28 3.1 Model input data sources for the Lam Takhong basin 76 3.2 List of calibrated parameters and their default 78 3.3 Qual2K input data of the worksheets and their sources 89 3.4 Headwater Boundary Data of Lam Takhong River in February 2019 90 3.5 Data of reaches in Lam Takhong River 91 3.6 The effluent standard for sanitary wastewater treatment systems (the Ministry of Natural Resources and Environment 2010) 94 3.7 Point sources input data along Lam Takhong River 94 3.8 Water quality monitoring stations in the Lam Takhong River 97 XV LIST OF TABLES (Continued) Table Page 3.9 Discharge data from urban areas in Lam Takhong watershed for calibration of Qual2k model in February 2019 101 3.10 Water quality in Lam Takhong River in 5 February 2019 101 3.11 Discharge data from urban areas in Lam Takhong watershed for validation of Qual2k model in November 2019 103 3.12 Water quality in Lam Takhong River in 28 November 2019 103 3.13 Equations, ranges, optimal values, and advantages and disadvantages for statistical performance measures in the Moriasi et al.