Assessing climate change impacts on surface water flow for sustainable exploitation and utilization of water resources in the srepok river basin in viet nam

VIET NAM NATIONAL UNIVERSITY, HANOI VIET NAM JAPAN UNIVERSITY VU THI HAI HA ASSESSING CLIMATE CHANGE IMPACTS ON SURFACE WATER FLOW FOR SUSTAINABLE EXPLOITATION AND UTILIZATION OF WATER RESOURCES IN THE SREPOK RIVER BASIN IN VIET NAM MASTER’S THESIS VIET NAM NATIONAL UNIVERSITY, HANOI VIET NAM JAPAN UNIVERSITY VU THI HAI HA ASSESSING CLIMATE CHANGE IMPACTS ON SURFACE WATER FLOW TOWARD SUSTAINABLE EXPLOITATION AND UTILIZATION OF WATER RESOURCES IN THE SREPOK RIVER BASIN IN VIET NAM MAJOR: CLIMATE CHANGE AND DEVELOPMENT CODE: 8900201.02QTD RESEARCH SUPERVISOR: Dr Akihiko Kotera Prof Dr Koshi Yoshida Ha Noi, 2021 DECLARATION I hereby declare that this thesis is the result of my research and has not been published The use of other research results and other documents must comply with the regulation The citations and references to documents, books, research, and websites must be listed as the thesis references Author of the thesis Vu Thi Hai Ha ACKNOWLEDGEMENT First and foremost, my appreciation and gratitude go to excellent supervisors for their guidance during the thesis research, namely Prof Dr Koshi Yoshida and Dr Akihiko Kotera They have been great mentors and always being available and responding to my emails and questions I would like to thank the National Center for Water Resources Planning and Investigation and the Vietnam Meteorological and Hydrological Administration for their enthusiastic support in providing materials and guiding me in writing my thesis I am also very grateful to the Danish Hydraulic Institute (DHI) offices in Ha Noi for the incredible internship assisting me in the modelling tutorial and MIKE license supply My special thanks go to Mr Nguyen Ngoc Bach, who gave me so much meaningful advice in study MIKE models I am very grateful for all the support, continuously encouragement, teaching and guidance from all the teachers of the MCCD program have extended to me during my time study here at Viet Nam Japan University, Hanoi National University Last but not least, I would like to express my indebtedness to my families and friends who have given me constant encouragement, great patience and utmost love to overcome all difficulties in the thesis completion Thank you very much! TABLE OF CONTENTS DECLARATION ACKNOWLEDGEMENT TABLE OF CONTENTS LIST OF TABLES i LIST OF FIGURES ii LIST OF ABBREVIATIONS iv CHAPTER INTRODUCTION 1.1 Background 1.2 The research question and hypothesis 1.3 Research objectives and tasks 1.4 Objects and scope of the research 1.5 Matrix of learning outcomes for the master's thesis 1.6 Contribution of the thesis 1.7 Framework of the Master’s thesis 1.8 Literature review 1.9 Overview of the study area 12 1.9.1 Description of study area 12 1.9.2 River system 13 1.9.3 Socio-economic features 17 1.10 Overview climate change in Viet Nam and the Srepok river basin 18 CHAPTER MATERIALS AND METHODS 22 2.1 Data collection 22 2.1.1 Topography document 22 2.1.2 Hydro-meteorological data 22 2.1.3 Water demand data 26 2.1.4 Reservoirs and hydropower plants data 28 2.2 Rainfall-runoff and water balance models 28 2.2.1 MIKE NAM model 29 2.2.2 The MIKE HYDRO BASIN model 40 CHAPTER RESULTS AND DISCUSSIONS 48 3.1 Calibration and validation of MIKE NAM model 48 3.2 Calibration and validation of MIKE HYDRO BASIN model 53 3.3 Impacts of climate change on flow 55 3.3.1 The average annual flow 56 3.3.2 The average flow in the rainy season 57 3.2.3 The average flow in the dry season 58 3.4 Assessing the capacity of sustainable exploitation and using water resources under the context of climate change 59 3.4.1 Water demand assessment 59 3.4.2 Assessing the capacity of sustainable exploitation and using water resources under the context of climate change 61 CHAPTER SOLUTION AND RECOMMENDATION 67 4.1 Problems exist 67 4.2 Solution and recommendation 68 4.2.1 Innovation of policy and management: IWRM (Solutions for water resource management) 68 4.2.2 Climate change 69 4.2.3 Agriculture and solutions 70 4.2.4 Structural measures in the Srepok river basin 71 4.2.5 Recommendations to the government 72 CHAPTER CONCLUSIONS AND RECOMMENDATIONS 73 5.1 Conclusion 73 5.2 Recommendation 74 5.2.1 Limitations 74 5.2.2 Recommendations for further study 75 REFERENCES 76 APPENDIX 82 Appendix A: The MIKE NAM model results 82 Appendix B: The water demand in the Srepok river basin 86 Appendix C: The reservoirs and hydropower plants information 86 Appendix D: The rainfall projection 101 LIST OF TABLES Table 1.1: Research question and hypothesis Table 1.2: Objective and tasks Table 1.3: Relations between results of the Master's thesis and MCCD's Program Learning Outcomes (PLOs) Table 1.4: Characteristics of the main tributaries in the Srepok river basin in Viet Nam 14 Table 1.5: Average monthly flow in 1980-2015 in the Srepok Basin (m³/s) 16 Table 2.1: List of rainfall stations used in MIKE NAM 23 Table 2.2: The variation of annual average rainfall compared to the baseline period in four provinces in the Srepok river basin 24 Table 2.3: Changes in seasonal rainfall (%) compared with the baseline period in four provinces in the Srepok river basin 25 Table 2.4: Water demand in the Srepok river basin (million m3) 26 Table 2.5: Reservoirs and hydropower plans 28 Table 2.6: MIKE NAM model parameter 31 Table 2.7: The sub-basins in the Srepok river basin 32 Table 2.8: The evaporation and rainfall stations in the area of Duc Xuyen station 34 Table 2.9: The evaporation and rainfall stations in the area of Cau14 station 35 Table 2.10: The evaporation and rainfall stations in the area of Giang Son station 36 Table 2.11: The calibration and validation period of MIKE NAM 40 Table 2.12: The average monthly flow for the 1986-2015 period (m3/s) in the Srepok river basin 43 Table 2.13: Hydropower plants information in Srepok river basin 46 Table 2.14: The calibration and validation period of MIKE HYDRO BASIN 47 Table 3.1: The parameter of calibration and validation model 49 Table 3.2: Results of calibration and validation of MIKE– NAM model at three hydrological stations Giang Son, Duc Xuyen and Cau 14 in the study basin 51 Table 3.3: Criteria evaluation result of calibration and validation of MIKE HYDRO BASIN model at hydrological stations Giang Son and Cau 14 54 Table 3.4: Water demand deficit in 2017 (million m3) 61 Table 3.5: Water demand deficit in 2017 by sector (million m3) 62 Table 3.6: Water demand deficit in 2030 with P=85% (million m3) 62 Table 3.7: Water demand deficit in 2030 with P=85% by sector (million m3) 63 Table 3.8: Water demand deficit in 2030 with P=50% (million m3) 64 Table 3.9: Water demand deficit in 2030 with P=50% by sector (million m3) 64 Table 3.10: The percentage reduces to meet the 85% water supply in agriculture 65 i LIST OF FIGURES Figure 1.1: Framework of the thesis Figure 1.2: The Srepok river basin 12 Figure 1.3: The Srepok River system 14 Figure 1.4: Average monthly water level at Cau 14 station in 1980–2018 15 Figure 1.5: Average monthly water level at Duc Xuyen station in 1980–2018 15 Figure 1.6: Average monthly water level at Giang Son station in 1980–2018 16 Figure 1.7: The percentage of annual average surface water resources of sub-basins in the Srepok river basin in 1980-2015 17 Figure 1.8: Temperature in some stations in the Srepok river basin (oC) 20 Figure 1.9: Rainfall in some stations in the Srepok river basin (mm) 21 Figure 2.1: The hydro-meteorological stations, reservoirs and hydropower plants network 23 Figure 2.2: The process and concept for the MIKE NAM and MIKE HYDRO BASIN models 29 Figure 2.3 Structure of NAM model 30 Figure 2.4: Sub-basin in MIKE NAM model 33 Figure 2.5: Thiessen polygon calculates the average rainfall of the basin to the Duc Xuyen hydrological station 35 Figure 2.6: Thiessen polygon calculates the average rainfall of the basin to the Cau 14 hydrological station 36 Figure 2.7: Thiessen polygon calculates the average rainfall of the basin to the Cau 14 hydrological station 37 Figure 2.8: Thesis’s MIKE HYDRO BASIN model setting 42 Figure 2.9: Water users connected to the river network in thesis 44 Figure 2.10: Reservoir information in the thesis 45 Figure 2.11: The position of Reservoir and Hydropower plant in thesis’s model 46 Figure 3.1: Calibration and validation in Giang Son station 48 Figure 3.2: Calibration and validation in Duc Xuyen station 48 Figure 3.3: Calibration and validation in Cau 14 station 48 Figure 3.5: Frequency curve and respective flow values calculation by computer program FFC 2008 53 Figure 3.6: Observed and simulated flow at Giang Son station and Cau 14 station 54 Figure 3.7: Average annual flow in 1986–2005 and 2016–2035 periods 56 Figure 3.8: The average annual flow change in 1986–2005 and 2017–2035 periods 56 Figure 3.9: The average flow years in the rainy season 57 Figure 3.10: The average flow years change in the rainy season 57 Figure 3.11: The average annual flow in the dry season 58 Figure 3.12: The average annual flow years in the dry season 58 Figure 3.13: The water demand in 2017 60 ii Figure 3.14: The water demand in 2030 60 Figure 3.15: The water demand by sector in 2017 60 Figure 3.16: The water demand by sector in 2030 61 iii No Reservoir Bottom level (m) Dead zone level (m) Dam crest level (m) Srepok3 222 268 277.5 Krong No 520 554.5 560 EaNhai 478 492 495 DakMinh 176 192 203.5 Ia Glai 552 567 575 Hoang An 632 647 657.5 YangReh 430 432 440.7 KrongBukha 460 469 486 10 EaUy 452 458 470 11 EaSoupThuong 192 205.4 219 12 EaSoupHa 191 193.4 198.2 13 EaKao 407 414 422.5 14 EaBong 440 446.3 458 15 BuonYong 481 494.5 510 16 BuonTriet 425 429 446 17 BuonTuaSrah 427 465 492.3 18 BuonKuop 381 409 415 Elevation – Area – Volume of reservoirs Buon Tua Srah # Elevation(m) Area (km2) Volume (106 m3) 427 0 430 0.77 0.77 435 1.85 7.13 440 4.15 21.75 445 7.07 49.47 450 8.89 89.3 455 10.71 138.23 460 12.52 196.24 465 14.73 264.29 10 470 17.29 344.25 87 # Elevation(m) Area (km2) Volume (106 m3) 11 475 19.97 437.34 12 480 25.24 550.11 13 485 32.59 694.31 14 490 41.64 879.43 15 495 52.46 1114.15 16 500 64.65 1406.4 Srepok # Elevation(m) Area (km2) Volume (106 m3) 175 0 178 0.0005 180 0.0051 183 0.01 0,0217 185 0.06 0.0986 187 0.13 0.2821 188 0.19 0.4394 190 0.34 0.9604 194 0.74 3.1694 10 196 0.95 4.8563 11 198 1.21 7.0105 12 200 1.49 9.7058 13 202 1.98 13.1665 14 204 2.37 17.5047 15 206 2.92 22.7802 16 208 3.41 29.1028 17 210 36.5025 18 212 7.74 45.2332 88 Srepok # Elevation(m) Area (km2) Volume (106 m3) 222 0 224 0.001 0.001 226 0.002 0.004 228 0.01 0.015 230 0.032 0.055 232 0.107 0.186 234 0.113 0.406 236 0.254 0.764 238 0.436 1.446 10 240 0.659 2.533 11 242 0.936 4.12 12 244 1.279 6.326 13 246 1.843 9.431 14 248 2,338 13.602 15 250 2.937 18.886 16 252 3.677 25.466 17 254 4.557 33.684 18 256 5.629 43.851 19 258 6.652 56.118 20 260 7.927 70.678 21 262 9.309 87.896 22 264 10.723 107.91 23 266 11.907 130.53 24 268 13.716 156.13 25 270 15.751 185.58 26 272 17.676 218.99 27 274 19.54 256.19 28 276 21.596 297.3 29 278 23.775 342.66 30 280 26.299 392.64 89 Ea Soup Thuong # Elevation(m) Area (km2) Volume (106 m3) 192 0 205.4 2.46 11 217.6 17.22 146.935 218.7 17.26 153.6 220 18.02 168.2 Krong No # Elevation(m) Area (km2) Volume (106 m3) 520 0 522 0.003 0.002 524 0.016 0.019 526 0.033 0.066 528 0.07 0.167 530 0.113 0.349 532 0.147 0.609 534 0.184 0.94 536 0.244 1.366 10 538 0.34 1.948 11 540 0.448 2.734 12 542 0.554 3.734 13 544 0.758 5.04 14 546 0.897 6.694 15 548 1.091 8.678 16 550 1.277 11.043 17 552 1.463 13.781 18 554 1.647 16.889 90 # Elevation(m) Area (km2) Volume (106 m3) 19 556 1.848 20.382 20 558 2.163 24.389 21 560 2.474 29.023 22 562 2.884 34.376 Yangreh # Elevation(m) Area (km2) Volume (106 m3) 430 0 432 1.35 0.9 437 2.7 6.3 439,5 2.72 8.6 441 2.75 10.07 IaGlai # Elevation(m) Area (km2) Volume (106 m3) 552 0 567 0.08 0.4 576 0.45 3.6 578 0.59 5.1 EaNhaiI # Elevation(m) Area (km2) Volume (106 m3) 478 0 492 0.11 0.5 495 2.05 11.6 498 3.53 23.5 91 Ea Bong # Area (km2) Elevation(m) Volume (106 m3) 440 0 446.3 0.29 0.6 455.5 1.7 8.76 457 3.1 17.58 459 3.12 19.75 HoangAn # Elevation(m) Area (km2) Volume (106 m3) 632 0 647 0.1 0.5 657.5 0.61 5.2 659.25 0.65 5.9 Buon Triet # Elevation(m) Area (km2) Volume (106 m3) 425 0 429 0,23 0.3 443 3.5 21 444.2 3.91 25 446 4.14 29 Buon Yong # Elevation(m) Area (km2) Volume (106 m3) 481 0 494.5 0.47 2.1 92 506.8 1.8 15.5 508.4 1.9 17.34 511 2.04 20.35 Krong Bukha # Elevation(m) Area (km2) Volume (106 m3) 460 0 469 4.53 13.6 483 12.48 95.7 483.8 13.74 109 490 13.92 139.24 Ea Soup Ha # Elevation(m) Area (km2) Volume (106 m3) 191 0 193.4 2.81 2.25 196 4.53 7.55 197.2 4.96 10.25 199 5.15 13.74 Eauy # Elevation(m) Area (km2) Volume (106 m3) 452 0 458 0.1 0.2 468 1.52 8.1 470 1.63 9.8 DakMinh # Elevation(m) Area (km2) 93 Volume (106 m3) 176 0 192 0.09 0.5 203.5 0.91 8.3 206 1.48 14.8 Ea Kao # Elevation(m) Area (km2) Volume (106 m3) 407 0 414 1.71 420 4.08 17.7 421.3 5.24 25 423 5.29 28.2 Reduce water use at low lake level rude Buon Tua Srah Time Elevation Ratio Elevation Ratio Elevation Ratio Elevation Ratio Jan 487.5 487.5 0.8 481.8 0.4 465 Feb 487.5 487.5 0.8 480.6 0.4 465 Mar 487.5 487.5 0.8 479 0.4 465 Apr 487.5 487.5 0.8 476.3 0.4 465 May 487.5 487.5 0.8 471.7 0.4 465 Jun 487.5 487.5 0.8 468.4 0.4 465 Jul 487.5 466.2 0.8 465 0.4 465 Aug 487.5 481 0.8 465 0.4 465 Sep 487.5 482.5 0.8 466.4 0.4 465 Oct 487.5 485.4 0.8 476 0.4 465 Nov 487.5 486 0.8 476.5 0.4 465 Dec 487.5 486 0.8 478 0.4 465 94 Jan 487.5 487.5 0.8 481.8 0.4 465 Srepok Time Elevation Ratio Elevation Ratio Elevation Ratio Elevation Ratio Jan 272 271.5 0.8 271 0.6 268 Feb 272 271.5 0.8 271 0.6 268 Mar 272 271.5 0.8 271 0.6 268 Apr 272 271.5 0.8 268.5 0.6 268 May 272 271.5 0.8 268.5 0.6 268 Jun 272 271.5 0.8 268.5 0.6 268 Jul 272 271.5 0.8 270 0.6 268 Aug 272 271.5 0.8 270 0.6 268 Sep 272 271.5 0.8 270 0.6 268 Oct 272 271.5 0.8 270 0.6 268 Nov 272 271.5 0.8 270 0.6 268 Dec 272 271.5 0.8 270 0.6 268 Srepok Time Elevation Ratio Elevation Ratio Elevation Ratio Elevation Ratio Jan 207 207 0.8 207 0.4 204 Feb 207 207 0.8 207 0.4 204 Mar 207 207 0.8 207 0.4 204 Apr 207 205.7 0.8 204 0.4 204 May 207 204.5 0.8 204 0.4 204 Jun 207 204 0.8 204 0.4 204 Jul 207 207 0.8 207 0.4 204 Aug 207 207 0.8 207 0.4 204 95 Time Elevation Ratio Elevation Ratio Elevation Ratio Elevation Ratio Sep 207 207 0.8 207 0.4 204 Oct 207 207 0.8 207 0.4 204 Nov 207 207 0.8 207 0.4 204 Dec 207 207 0.8 207 0.4 204 Jan 207 207 0.8 207 0.4 204 YangReh Elevatio n Ratio Elevation Ratio Elevation Ratio Elevation Ratio 1/1/2017 00:00:00 435 0.8 435 0.85 435 0.85 435 0.85 1/1/2018 00:00:00 435 0.8 435 0.85 435 0.85 435 0.85 Time EaBong Elevation Ratio Elevation Ratio Elevation Ratio Elevation Ratio 1/1/2017 00:00:00 455.5 0.8 455.5 0.85 455.5 0.85 455.5 0.85 1/1/2018 00:00:00 455.5 0.8 455.5 0.85 455.5 0.85 455.5 0.85 Time EaKao Elevation Ratio Elevation Ratio Elevation Ratio Elevation Ratio 1/1/2017 00:00:00 420 0.8 420 0.85 420 0.85 420 0.85 1/1/2018 00:00:00 420 0.8 420 0.85 420 0.85 420 0.85 Time 96 EaSupHa Elevation Ratio Elevation Ratio Elevation Ratio Elevation Ratio 1/1/2017 00:00:00 196 0.8 196 0.85 196 0.85 196 0.85 1/1/2018 00:00:00 196 0.8 196 0.85 196 0.85 196 0.85 Time EaSupThuong Elevation Ratio Elevation Ratio Elevation Ratio Elevation Ratio 1/1/2017 00:00:00 217.6 0.8 217.6 0.85 217.6 0,85 217.6 0.85 1/1/2018 00:00:00 217.6 0.8 217.6 0.85 217.6 0,85 217.6 0.85 Time KrongBuk Hạ Time Elevation Ratio Elevation Ratio Elevation Ratio Elevation Ratio Jan 483 482.17 0.8 480.48 0.4 469 Feb 483 480.21 0.8 477.34 0.4 469 Mar 483 478.26 0.8 474.18 0.4 469 Apr 483 477.77 0.8 473.13 0.4 469 May 483 469 0.8 469 0.4 469 Jun 483 472.15 0.8 469 0.4 469 Jul 483 473.59 0.8 470.37 0.4 469 Aug 483 476.51 0.8 473.11 0.4 469 Sep 483 480.08 0.8 477.16 0.4 469 Oct 483 482.27 0.8 480.07 0.4 469 Nov 483 483 0.8 482.53 0.4 469 Dec 483 483 0.8 482.24 0.4 469 Jan 483 482,17 0.8 480.48 0.4 469 97 Dak Minh Time Elevation Ratio Jan 203.5 Feb 203.5 Mar 203.5 Apr 203.5 May 203.5 Jun 203.5 Jul 203.5 Aug 203.5 Sep 203.5 Oct 203.5 Nov 203.5 Dec 203.5 Jan 203.5 Hoang An Time Elevation Ratio Jan 657.5 Feb 657.5 Mar 657.5 Apr 657.5 May 657.5 Jun 657.5 Jul 657.5 Aug 657.5 Sep 657.5 Oct 657.5 98 Time Elevation Ratio Nov 657.5 Dec 657.5 Jan 657.5 IaGlai Time Elevation Ratio Jan 576 Feb 576 Mar 576 Apr 576 May 576 Jun 576 Jul 576 Aug 576 Sep 576 Oct 576 Nov 576 Dec 576 Jan 576 Ea KrongNo3 Time Elevation Ratio Jan 555 Feb 555 Mar 555 Apr 555 May 555 99 Time Elevation Ratio Jun 555 Jul 555 Aug 555 Sep 555 Oct 555 Nov 555 Dec 555 Jan 555 BuonYong Time Elevation Ratio 1/1/2017 00:00:00 506.8 0.85 1/1/2018 00:00:00 506.8 0.85 Buon Triet Time Elevation Ratio 1/1/2017 00:00:00 443 0.85 1/1/2018 00:00:00 443 0.85 100 Appendix D: The rainfall projection Because the file is too long, it will be printed and attached later 101 ... the context of climate change For this purpose, the thesis "Assessing Climate Change Impacts on Surface Water Flow toward Sustainable Exploitation and Utilization of Water Resources in the Srepok. .. on the surface flow and water balance change of the Srepok river basin in Viet Nam under climate change to support the sustainable exploitation and use of water resources 1.5 Matrix of learning... ? ?Assessing Climate Change Impacts on Surface Water Flow toward Sustainable Exploitation and Utilization of Water Resources in the Srepok river basin in Viet Nam? ?? will provide an overview of the