HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT COASTAL EROSION IN MEKONG DELTA & PROTECTION SOLUTIONS Thong NGUYEN et al. Tel. 098 99 66 719 Email: nthong 56@yahoo. fr 11/1/2020 1 1

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANAGEMENT 1. 2. 3. 4. 11/1/2020 Assoc. Prof. Nguyễn Thống Dr. Hồ Tuấn Đức Dr. Lưu Xuân Lộc MSc. Lê Ngọc Anh 2 2

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANAGEMENT CONTENT 1. Overview & Methodology 2. Region zone 3. Local & study zone 4. Results and discussions 5. Perspectives & Conclusion 11/1/2020 3

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANAGEMENT 1. OVERVIEW & METHODOLOGY 11/1/2020 4

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Research group was involved in: • Work package 4. 1: Wave calculation in regional and local zone for U Minh, using TOMAWAC module; • Work package 4. 2: Calculation of coastal currents in regional and local zone for U Minh, using TELEMAC (driven by wind, wave, tide and flow from estuary) 11/1/2020 5 5

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT • Work package 5. 1: Simulation of suspension and sediment transport at Mekong Delta’s estuaries and coastal area near Cà Mau-U Minh (TELEMAC + SYSIPHE). • Work package 5. 2: Hydrodynamic model for studied area in U Minh 11/1/2020 6 6

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT • Work package 5. 3: Understand the erosion process at coastal area of U Minh -Cà Mau by numerical model. • Work package 6. 2: Evaluate the shore protection works by using TELEMAC + SYSIPHE 11/1/2020 7 7

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT METHODOLOGY è Numerical model. è Hydrodynamic model for southern area of East Sea: Telemac 2 D + Tomawac (region zone). è Hydrodynamic model & morphology for local & study zone: Telemac 2 d + Tomawac + Sisyphe. 11/1/2020 8 8

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANAGEMENT COASTAL AREA IN THE DOWNSTREAM OF MEKONG RIVER (LMDCZ) Study zone 11/1/2020 9 9

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANAGEMENT 2. COASTAL AREA IN THE DOWNSTREAM OF THE MEKONG RIVER (region zone) 11/1/2020 10

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Study zone: Region zone Vĩnh Long Vũng Tàu Cần Thơ Cà Mau 11/1/2020 303000 elements Max = 9 km Min = 8 m Coastal = 250 m 11 11

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT BOUNDARY CONDITIONS East Sea 11/1/2020 12

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Bathymetry & bound. cond. Bathymetry: - Coastal: SIWRR - Offshore: ETOPO 1 with x=900 m. Liquid bound. : Astronomical tide from TPXO with 9 main tides: K 1, O 1, P 1, Q 1 , S 2, N 2, K 2, M 2 và M 4. Wind, wave: Data from NOAA. 11/1/2020 13

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Model calibration & validation 11/1/2020 14

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Wind (1 -2014) 11/1/2020 15

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Wind (8 -2014) 11/1/2020 16

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Q (m 3/s) Boundary Q 1 & Q 2 (1 -2014) Mỹ Thuận Q 1(t) 20000 15000 10000 5000 -5000 1 32 63 94 125 156 187 218 249 280 311 342 373 404 435 466 497 528 559 590 621 652 683 714 0 Q (m 3/s) -10000 Cần Thơ Q 2(t) T (h) 15000 -5000 1 32 63 94 125 156 187 218 249 280 311 342 373 404 435 466 497 528 559 590 621 652 683 714 5000 11/1/2020 -15000 17 T (h)

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Tidal boundary (1 -2014) 11/1/2020 18

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Wave boundary HM 0 (1 -2014) T (ngày) 11/1/2020 19

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Wave boundary HM 0 (8 -2014) T (ngày) 11/1/2020 20

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT TRẦN ĐỀ Z (m) Tidal (1 -1 -2014 15 -1 -2014) 2. 50 2. 00 1. 50 1. 00 0. 50 0. 00 -0. 50 0 -1. 00 -1. 50 -2. 00 11/1/2020 -2. 50 Observation 48 96 144 192 240 Calculation 288 336 T (h) 21

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT GÀNH HÀO Z (m) Tidal (1/1/2014 15/1/2014) 3. 00 Observation Calculation 2. 00 1. 00 0. 00 -1. 00 0 48 96 144 192 240 288 336 -2. 00 -3. 00 11/1/2020 T (h)22

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT RẠCH GIÁ Z (m) Tidal (1/1/2014 15/1/2014) 1. 00 Observation Calculation 0. 80 0. 60 0. 40 0. 20 0. 00 -0. 20 0 11/1/2020 -0. 40 48 96 144 192 240 288 336 T (h) 23

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Preliminary results èHydrodynamics è Wave è Sediment transport 11/1/2020 24

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Mean velocity field (1 -2014) 11/1/2020 25

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Mean velocity field (8 -2014) Site U Minh 11/1/2020 26

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Mean velocity field (8 -2014) Local U Minh 11/1/2020 Animation: SIWRR_Hydro. avi 27

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Comments è Mean velocity field in January 2014 is quite large comparing to that in August 2014 è Formation of coastal currents toward the south during January 2014 è Mean currents in August 2014 is minor. 11/1/2020 28

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Wave field HM 0 at 12 H, 13/1/2014 Vĩnh Long Cần Thơ Cà Mau 11/1/2020 29

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Average wave field HM 0 in January 2014 11/1/2020 30

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Wave field HM 0 at 24 H, 15/8/2014 11/1/2020 31

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Average wave field HM 0 in August 2014 11/1/2020 Animation: SIWRR_Wave. avi 32

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT COMMENTS èWaves in Jan. 2014 tends to be larger than in August 2014. è Waves in the West tends to be intensified by Southwest wind. 11/1/2020 33

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT WAVE HM 0(t) (1 -2014) HM 0 (m) T (ngày) 11/1/2020 34

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT WAVE HM 0(t) (8 -2014) 11/1/2020 35

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT COMMENTS è In Jan. 2014, North. East wind is dominant waves in East Sea are intensified. è In Aug. 2014, South. West wind is dominant waves in East Sea are reduced. 11/1/2020 36

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANAGEMENT 5. RESULTS & PERSPECTIVES 11/1/2020 37

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT CONCLUSIONS è Wind direction affects significantly the distribution of wave intensity in the East Sea and West Sea. è Southwest winds intensify the waves in the West Sea. è The sediment transport rates are important in estuary area and in the main rivers in Mekong. 11/1/2020 38

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT èIn addition to the sediment from the upstream of the Mekong river, the sediment transport due to morphology changes also plays an important role. è The coastal erosion / acrreation rate at U Minh is less than in other areas. 11/1/2020 39

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT Hydraulic regime in the West Sea is quite complex. èSimulation results and observation are quite different. è could be the complexity of bathymetry and tidal conditions. 11/1/2020 40

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT WHAT TO DO NEXT. . . èDevelop the own grid system for U Minh area. è Simulation for the years with available flow and stage data (2015, 2016). è Impact assessment of mangrove and maleleuca fences. 11/1/2020 41

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT WHAT TO DO NEXT. . . è Update and complete the coastal bathymetry. è Simulation of shore protection works: semi-submerged groyne. 11/1/2020 42

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING- DEPARTMENT OF WATER RESSOURCES ENGINEERING & MANEGEMENT 11/1/2020 43