Assessment of salinity intrusion in the red river delta vietnam

ASSESSMENT OF SALINITY INTRUSION IN THE RED RIVER DELTA VIETNAM by Le Thi Thu Hien B A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering Examination Committee: B Dr Roberto Clemente (Chairman) Dr Sutat Weesakul (Co-chairman) B Prof Ashim Das Gupta B Dr Mukand S Babel B Nationality: Vietnamese Previous degree: Bachelor of Engineering in Water Resources Engineering Water Resources University Hanoi, Vietnam Fellowship Donor: The Government of Denmark Asian Institute of Technology School of Civil Engineering Thailand May 2005 -1 - TABLE OF CONTENTS Chapter Title Page TITLE PAGE i ABSTRACT ii ACKNOWLEDGEMENTS iii TABLE OF CONTENTS iv LIST OF TABLES vii LIST OF FIGURES viii I INTRODUCTION 1.1 Problem Identification 1.2 Study Area Introduction 1.2.1 1.2.2 1.2.3 Geographical Condition Hydrological Condition Hydraulic Constructions in Study Area Hoabinh Hydropower Plant Son la Hydropower Plant: On-Going construction 1.2.4 Tidal Regime and Salinity Intrusion 1.2.5 Existing Land Use In general In Coastal zone Area II 1.3 Objectives of Study 10 1.4 Scope of Study 10 LITERATURE REVIEW 11 2.1 Theoretical Study of Dispersion Coefficient and Salinity Intrusion 11 2.2 III 6 2.1.1 Mathematical Formulas 2.1.2 Numerical Models 2.1.3 Salinity Intrusion Study in Vietnam Salinity Control Requirement for Irrigation and Aquaculture 11 16 17 18 THEORETICAL CONSIDERATIONS 19 3.1 Characteristics of Estuary 3.1.1 Stratified Estuary 3.1.2 Partially Mixed Estuary Title 19 20 20 Page 3.1.3 Well Mixed Estuary iv Numerical Computation 20 21 3.2.1 3.2.2 22 22 Chapter 3.2 3.3 Finite Difference Tidal Hydraulics Equations - Balance Equations Finite Difference- Salt Model characteristics 23 Chapter I INTRODUCTION 1.1 Problem Identification Intrusion of salt-water in dry season is a well-known phenomenon in the RedThaibinh estuaries In the rainy season from June to November the discharge of freshwater from upstream is high, the saltwater is pushed to the sea and the problem of salinity intrusion is not present But in the dry season from December to May of the next year the discharge of freshwater from upstream is small and the salinity intrusion problem becomes serious In some branches of the Red river system, the distance of salinity intrusion may be up to 40 km As the increasing of the freshwater intake for irrigation, the salinity intrusion is causes a lot of problems for irrigation, aquaculture and other economic activities due to lack of freshwater The knowledge of the characteristics of salinity intrusion therefore is very necessary for solving the problems and utilizing the river Saltwater intrusion in Red river delta has been studied for several years ago Many institutions involve research works for controlling and predicting Red-river salinity intrusion by various methods with mathematical models VRSAP (Water Resources Planning Institute, Hanoi Water Resources University), TL1, TL2 (Institute of Mechanics), the hydrological and meteorological models (Hydrological and Meteorological Services), the multivariable relational model (Institute for water resources research) However there is a lack of efficient numerical hydrodynamic models that consider effect of Hoabinh reservoir as well as calculation and prediction salinity intrusion in Red river delta Sonla Hydropower Plant is going to built in upstream of Da River to reduce flood damage and improve irrigation in the Red River Delta Increasing inflow for irrigation in dry season can cause a change of salinity concentration for planning aquaculture area in Red River Delta’s coastal zone How to supply sufficient freshwater for paddy crops while controlling salinity concentration for aquaculture area? This is an important issue to assess the entire effect of Sonla Hydropower Plant to downstream area Moreover, global climate changes in some recent years have deep effect to hydrology condition of Red river delta “Global Warning” could cause sea level rise 0.5 to meter by the current century due to the “Greenhouse Effect” A rise in sea level enables salt water penetrates upstream and inland, and would threaten human uses of water particularly during droughts To bring a reasonable operation for both electric production and saltwater prevention is urgent duty of Hoabinh reservoir in the future, finding a numerical model for simulation and prediction salinity intrusion in Red river delta for future is also very important 1.2 Study Area Introduction 1.2.1 Geographical Condition Red - Thai Binh River System is the second largest river system in Vietnam, after Mekong River It originates from Nguy Son Mountain in Yunnan province of China -2 - Sông Chảy Sông Lô Sông Cấm Sông Đà Sông Hồng Sông Lục Nam Đầm Vân Trì Sông Đuống Sông Diễn Vọng Sông Thái Bình Sông Kinh Trai Sông Hà Sông Hàn Hồ Sông Đình Đào Sông Luộc Sông Bôi Sông Đáy Sông Chu Fig 1.1 Red River System in Vietnam Territory The whole basin areas occupy 169,020km2 of which 86,720km2 (representing 51%) are located in Vietnam’s territory as shown in Fig.1.1 and Fig.1.2 It is a population density area with high economic potential The North Delta and Midland Region cover 14,590km2 with a population of 18.56 millions in the year 2000 P P P P P P As a large river basin with a complex topography including mountains and hills (covering 90% of the area), delta and coastal areas, the Red - Thai Binh river basin, hosting a diverse and more and more developed socio-economy, makes a significant contribution to the national economy Figure 1.2 River Network in Red River Delta -3 - Fig 1.3 Study Area 1.2.2 Hydrological Condition The Red River Delta is in reality the delta of two river systems: the Red River System and Thai binh River System The Red River System consists of major river branches namely the Da, Lo and the Thao Rivers The Thaibinh River System is also comprised of river branches, which are the Cau River, Thuong and the Luc Nam River as shown in Figure 1.4 The two river systems are connected through the Duong and Luoc rivers forming the Red and Thaibinh River Basin SCHEMA OF RIVER SYSTEM Da River Thao River Lo River Cau River Thuong River Hoabinh Reservoir Lucnam River Phalai Viettri Duong River Thaibinh River Sontay Luoc River Hanoi Red River East Fig 1.4 Schema of River Network System 29 Sea Table 1.1 Catchment’s Area and Distributed Flow of Red River Delta’s Branches Catchment’s Area Area Percentage in Red River Delta (km2) (%) Da 27585.11 31.1 41.3 Lo 21003.44 23.1 24.1 Thao 8658.47 30.6 21.5 Upper Thaibinh 11757.88 7.5 6.6 Red + Day 15555.13 7.7 6.3 Catchments P P Distributed Flow to Red and Thaibinh river (%) Water resource of Red River is plentiful Annual average volume at Sontay station is 114km3 corresponding with 3643m3/s of discharge Inflow in Thaibinh River is less low due to upstream rivers of Thaibinh River (Cau, Thuong, Lucnam) have annual inflow very small Total water volume of Thaibinh river at Phalai is 8.26km3 (equal to 7.2% ones of Red river at Sontay station) with annual discharge is 318m3/s P P P P P P P P Apart from inflow from Cau, Thuong and Luc Nam River, one numerous inflow is passed from Red River at downstream of Phalai through Duong River This flow is nearly triple are compared with Thaibinh’s (25km3 compare with 8.26km3) In addition, Thaibinh River also gets supplementary volume from Red river through Luoc River with total volume is 13 km3 per year before flowing to the sea P P P P P P In the dry season, water level in Red River fall down very low; in somewhere freshwater altitude of river is less than altitude of field’s surface inside the dyke However, water resources of Red River keep in plentiful state so the lowest monthly average inflow at Sontay is 691m3/s P P 1.2.3 Hydraulic Constructions in Study Area Hoabinh Hydropower Plant Hoabinh Hydropower Plant was built in 1980 in the northern mountainous province of Hoabinh with assistance from the former Soviet Union Major objectives U • • • Flood prevent for whole Red River Delta Electricity generation Water supply for irrigation to whole of downstream Red River Delta in dry season Some characteristics of Hoabinh reservoir U • • • • • • • Surface of the reservoir F=200 km2 Length L=230 km Average width B=1 km Average depth H=50 m Volume V=9.5 billion m3 Capacity P=1,920 MW Average annual production of electricity E=8 billion KWh 30 Hoabinh Hydropower Plant has been completely constructed in 1979 with electricity generation units It has raised the discharge of flow of Da (Black river) and Red rivers in dry season up to 400-600 m3/s The flow regulation also facilitates to put saltwater into river mouth in dry season P P Sonla Hydropower Plant: On-Going Construction Sonla Hydropower Project to be constructed on the Da River, it is far from Hoabinh Hydropower Plant nearly 250 km towards upstream and about 320 km of Hanoi The proposed Sonla Dam would be the largest dam in Vietnam The Sonla Hydropower Station Project will be the largest of its kind in south East Asia Sonla Hydropower together with Hoabinh Hydropower Plant will improve Vietnam's electricity fuel mix, reduce flood damage and improve irrigation in the Red River Delta Sonla reservoir will hold a total of 25 billion m3 of water Together with the Hoabinh reservoir, the water volume will total 36 billion m3 With the Sonla reservoir, safety discharge to Hoabinh in the dry season is 759 m3 /s, raising 115 m3/s if has only Hoabinh reservoir (Source: Proceedings of the Workshop on Methodologies for EIA of Development Projects, Hanoi, July, 1999) P P P P P P Electricity of Vietnam (EVN) plans begins construction on Sonla Hydropower Plant late 2005 First turbine expected operable 2012, the entire of construction expected compliable in 2015 Major objectives U • • • • Energy production: 14.16 billion KWh/year Regulation flood stream: very important for Hoabinh Dam and downstream areas, including Hanoi (ensuring water level in Hanoi during flood season not to exceed 13 m) Water supply: providing to the Red River Delta about billion m3; during dry season will ensuring a sanitary run-off of 300-600m3/sec Creating new opportunities for regional socio-economic development Some characteristics of construction U • • • • • Normal water level: 265 m Dam height: 177 m Volume of reservoir: 25.4 billion m3 Surface of reservoir: 440 km2 Installment capacity: 3.600 MW 31 Fig 1.5 Location of Sonla and Hoabinh Reservoirs 1.2.4 Tidal Regime and Salinity Intrusion The mixing of fresh and marine waters also is accelerated by tidal action The tidal regime in this area is irregularly diurnal, but is more regularly diurnal upstream The maximum tidal range along the coast of the Delta is approximately m The tidal transfer speed in the river mouth approaches 95-150 cm/sec and the tidal influence extend 150-180 km from the river mouths (Source: Nguyen Ngoc Thuy, 1982) Due to low terrain and improved river mouths so much, seawater and salinity are easy to go Red River Delta in almost of annual In Thaibinh River, low river bottom datum, large estuary and upstream inflow create a good condition for severe saltwater intrusion up far from the sea to Lucnam, Cau and Thuong River In the Red River, distance of saltwater intrusion was recorded at location which is 10 km far from Hanoi station above and 185 km far from the sea Salinities increase from about 0.5 ppt in the rivers to 30.0 ppt Fluctuation widely of salinity depends on the flow in the river and state of the tide Salinity concentration ppt can intrude about 30 – 40 km in average in the main branches with complicated characteristic 1.2.5 Existing Land Use Almost the entire delta has been reclaimed for agricultural land, aquaculture ponds, forestry and urban development Approximately 53% of the delta is agricultural land, 6.4% is forestry land and there are only some 3.8% of permanent lakes and ponds for aquaculture as shown in Fig 1.4 and Table 1.2 In general The principal land use throughout the delta is the annual cultivation of rice, in addition to the perennial crop as main fruit species Rice occupies around 93 percent of the total annual crop area as shown in Table 1.3 Corn, sweet potato and cassava followed behind The whole region produces about three million tons of rice per year (an average yield of 2,835 kg/ha in 1995) 32 To facilitate rice production, some 1,080 km of embankments, 34,400 km of canals, 1,310 drains, 217 reservoirs and 1,300 pumping stations have been constructed In spite of the low salinity of estuarine water, the production of table salt by traditional measures in estuarine waters has been developed Each year the salt fields of this area have provided North Vietnam a table salt production of 20,000 – 30,000 tons Table 1.2 Existing Land Use in 1998 (Unit: 1000 ha) Total Area Agricultural Land Forestry Land Aquaculture Land 1,266.3 671.8 80.9 48.7 Table 1.3 Agricultural Crop Land (Unit: 1000 ha) Annual Crop Land Perennial Crop Land Total Rice Land 620.9 576.4 33 10.1 Fig 1.6 Map of Land Use in Red River Delta In Coastal Zone Area Almost coastal zone area in Red River Delta no has agricultural land and has traditionally depended on fishing and salt production Production of catching fish is getting decreased Life of many stakeholders in the area is below poverty line Coastal zone has different sorts of water, including fresh water, brackish water and brine Brine surface: set for the exploitation of sea products Some main sea products are bream, Chinese herring, Khoai fish, grey mullet, Vuoc fish (perch), Van shrimps, Bop shrimps, and pawns At present, the seafood catching activities are natural and being carried out on small-scale A majority of aquatic products are used in processing traditional lines such as fish sauce, shrimp paste and seafood Area of brackish water surface: Being mainly available in the Red, Thaibinh and Traly river mouths thanks to an abundant source of short-lived creature, algas and aquatic botany as natural food used in process of breeding aquatic products Thaibinh province has about 20,705ha (Tienhai district has 9,949ha and Thaithuy district 10,756ha), of which 34 Water Level along Thaibinh River (scenario 2c) Water Level along Red River (scenario 2c) 10 10 1.9 1.9 9 1.8 1.8 8 1.7 1.7 7 1.6 1.6 Maximum Water Level (meter) 5 4 3 2 1 250000 W.L (meter) W.L (meter) W.L (meter) 11 1.5 150000 100000 50000 1.5 Maximum Water Level (meter) 1.4 1.4 1.3 1.3 1.2 1.2 1.1 1.1 100000 200000 W.L (meter) 11 80000 60000 40000 20000 Distance from river month (meter) Distance from river month (meter) Fig 6.114 Water Level along Red River (scenario 2c) Fig 6.115 Salinity Concentration along Thaibinh River (scenario 2c) 24 24 22 22 20 20 18 16 16 14 14 12 12 10 10 8 6 4 2 2.5 2.5 Maximum Salinity Concentration (psu) 2 1.5 1.5 1 0.5 70000 60000 50000 40000 30000 20000 10000 0.5 70000 60000 50000 40000 30000 20000 10000 Distance from river month (meter) Distance from river month (meter) Fig 6.116 Salinity Concentration along Red River (scenario 2c) 98 Fig 6.117 Salinity Concentration along Thaibinh River (scenario 2c) Salinity Concentration (psu) Maximum Salinity Concentration (psu) Salinity Concentration(psu)er) 26 Salinity Concentration (psu) Salinity Concentration(psu)er) Salinity Concentration along Red River (scenario 2c) 26 18 Water Level along Thaibinh River (scenario 2c) Downstream Trans Upstream Table 6.12 Hourly Averaged Flow Distribution in Estuaries (scenario 3a) River Station Red Da Lo Day Thaibinh Duong Luoc Red Traly Ninhco Day Thaibinh Vanuc Lachtray Dabac Cam Yenbai Hoabinh Vuquang Phuly Phalai Thuongcat Trieuduong Balat Dinhcu Phule Nhutan Dongxuyen Quangphuc Kienan Donghi Ben Phabinh Discharge Distribution (m3/s) % 12.8 174 48.4 660 22.5 307 1.3 18 14.9 204 19.5 266 10.2 139 16.2 214 11.9 156 8.8 116 17.8 234 3.8 50 10.9 143 7.7 101 2.3 30 20.6 271 Sum (m3/s) 1361.7 405.0 1315.9 Yenbai 174 (m3/s) (12.8%) Vuquang 307 (m3/s) (22.5%) Hoabinh 660 (m3/s) (48.4%) Phalai 204 (m3/s) (14.9%) Thuongcat 266 (m3/s) (19.5%) Hanoi (100%) Phuly 18 (m3/s) (1.3%) Trieuduong 139 (m3/s) (10.2%) 30 (m3/s) (2.3%) 271 (m3/s) (20.6%) 143 (m3/s) (10.9%) 101 (m3/s) 161 (m3/s) (7.7%) (11.9%) 50 (m3/s) (3.8%) 234 (m3/s) 116 (m3/s) 214 (m3/s) (17.8%) (8.8%) (16.2%) Fig 6.118 Hourly Averaged Flow Distribution in Estuaries (scenario 3a) 99 Water Level along Red River (scenario 3a) Water Level along Thaibinh River (scenario 3a) 11 11 10 10 9 8 7 6 2 1.9 1.9 4 3 2 1 250000 W.L (meter) 1.8 Maximum Water Level (meter) 1.7 1.7 1.6 1.6 1.5 1.5 1.4 1.4 1.3 1.3 1.2 1.2 1.1 1.1 W.L (meter) Maximum Water Level (meter) W.L (meter) W.L (meter) 1.8 200000 150000 100000 50000 Distance from river month (meter) 100000 80000 60000 40000 20000 Distance from river month (meter) Fig 6.119 Water Level along Red River (scenario 3a) Fig 6.120 Salinity Concentration along Thaibinh River (scenario 3a) 24 24 22 22 20 20 18 16 16 14 14 12 12 10 10 8 6 4 2 70000 60000 50000 40000 30000 20000 10000 2.5 2.5 Maximum Salinity Concentration (psu) 2 1.5 1.5 1 0.5 70000 0.5 60000 50000 40000 30000 20000 10000 Distance from river month (meter) Distance from river month (meter) Fig 6.121 Salinity Concentration along Red River (scenario 3a) 100 Fig 6.122 Salinity Concentration along Thaibinh River (scenario 3a) Salinity Concentration (psu) Maximum Salinity Concentration (psu) Salinity Concentration(psu)er) 26 Salinity Concentration (psu) Salinity Concentration(psu)er) Salinity Concentration along Red River (scenario 3a) 26 18 Water Level along Thaibinh River (scenario 3a) Table 6.13 Hourly Averaged Flow Distribution in Estuaries (scenario 3b) Downstream Trans Upstream River Discharge Distribution (m3/s) % 12.8 174 48.4 660 22.5 307 1.3 18 14.9 204 19.8 269 10.5 143 15.5 199 12.1 155 9.8 125 17.7 226 3.1 40 10.3 131 8.7 112 1.4 18 21.4 274 Station Red Da Lo Day Thaibinh Duong Luoc Red Traly Ninhco Day Thaibinh Vanuc Lachtray Dabac Cam Yenbai Hoabinh Vuquang Phuly Phalai Thuongcat Trieuduong Balat Dinhcu Phule Nhutan Dongxuyen Quangphuc Kienan Donghi Ben Phabinh Sum (m3/s) 1361.7 411.6 1279.5 Yenbai 174 (m3/s) (12.8%) Vuquang 307 (m3/s) (22.5%) Hoabinh 660 (m3/s) (48.4%) Phalai 204 (m3/s) (14.9%) Thuongcat 266 (m3/s) (19.8%) Hanoi (100%) Phuly 18 (m3/s) (1.3%) Trieuduong 143 (m3/s) (10.5%) 18 (m3/s) (1.4%) 274 (m3/s) (21.4%) 131 (m3/s) (10.3%) 112 (m3/s) 199 (m3/s) (8.7%) (15.5%) 40 (m3/s) (3.1%) 226 (m3/s) 125 (m3/s) 214 (m3/s) (17.7%) (9.8%) (16.2%) Fig 6.123 Hourly Averaged Flow Distribution in Estuaries (scenario 3b) 101 Water Level along Thaibinh River (scenario 3b) 10 10 1.9 1.9 9 1.8 1.8 8 1.7 1.7 7 1.6 1.6 6 1.5 1.5 Maximum Water Level (meter) 5 W.L (meter) 2 Maximum Water Level (meter) 1.4 4 3 2 1 250000 150000 100000 50000 1.3 1.2 1.2 1.1 1.1 80000 Water Level along Red River (scenario 3b) Fig 6.125 20000 Water Level along Thaibinh River (scenario 3b) 24 22 22 20 20 18 16 16 14 14 12 12 10 10 8 6 4 2 2.5 2.5 Maximum Salinity Concentration (psu) 2 1.5 1.5 1 0.5 Salinity Concentration (psu) Maximum Salinity Concentration (psu) Salinity Concentration(psu)er) 24 70000 40000 Salinity Concentration along Thaibinh River (scenario 3b) 26 Salinity Concentration (psu) Salinity Concentration(psu)er) Salinity Concentration along Red River (scenario 3b) 26 18 60000 Distance from river month (meter) Distance from river month (meter) Fig 6.124 1.4 1.3 100000 200000 W.L (meter) 11 W.L (meter) W.L (meter) Water Level along Red River (scenario 3b) 11 0.5 60000 50000 40000 30000 20000 10000 Distance from river month (meter) 70000 60000 50000 40000 30000 20000 10000 Distance from river month (meter) Fig 6.126 Salinity Concentration along Red River (scenario 3b) 102 Fig 6.127 Salinity Concentration along Thaibinh River (scenario 3b) Table 6.14 Hourly Averaged Flow Distribution in Estuaries (scenario 3c) Downstream Trans Upstream River Red Da Lo Day Thaibinh Duong Luoc Red Traly Ninhco Day Thaibinh Vanuc Lachtray Dabac Cam Discharge Distribution (m3/s) % 12.8 174 48.4 660 22.5 307 1.3 18 14.9 203 20.0 272 10.8 147 14.2 182 12.1 155 10.5 134 18.2 233 2.3 29 10.7 137 10.2 131 0.2 21.7 278 Station Yenbai Hoabinh Vuquang Phuly Phalai Thuongcat Trieuduong Balat Dinhcu Phule Nhutan Dongxuyen Quangphuc Kienan Donghi Ben Phabinh Sum (m3/s) 1361.5 419.3 1282.2 Yenbai 174 (m3/s) (12.8%) Vuquang 307 (m3/s) (22.5%) Hoabinh 660 (m3/s) (48.4%) Thuongcat 272 (m3/s) (20%) Phalai 203 (m3/s) (14.9%) Hanoi (100%) Phuly 18 (m3/s) (1.3%) Trieuduong 143 (m3/s) (10.5%) (m3/s) (0.2%) 278 (m3/s) (21.7%) 137 (m3/s) (10.7%) 131 (m3/s) 182 (m3/s) (10.2%) (14.2%) 29 (m3/s) (2.3%) 233 (m3/s) 134 (m3/s) 214 (m3/s) (18.2%) (10.5%) (16.2%) Fig 6.128 Hourly Averaged Flow Distribution in Estuaries (scenario 3c) 103 Water Level along Red River (scenario 3c) Water Level along Thaibinh River (scenario 3c) 10 10 9 8 6 Maximum Water Level (meter) 5 4 3 2.8 2.8 2.7 2.6 W.L (meter) 2.9 2.6 Maximum Water Level (meter) 2.5 2.5 2.4 2.4 2.3 2.3 2.2 2.2 2.1 2.1 W.L (meter) 2.9 2.7 W.L (meter) W.L (meter) 11 11 2 1 250000 150000 100000 50000 1.9 1.8 1.8 1.7 1.7 1.6 1.6 1.5 100000 200000 1.9 1.5 80000 Distance from river month (meter) Fig 6.129 Water Level along Red River (scenario 3c) Fig 6.130 40000 20000 Water Level along Thaibinh River (scenario 3c) Salinity Concentration along Thaibinh River (scenario 3c) Salinity Concentration along Red River (scenario 3c) 26 26 24 24 22 22 3 2.5 2.5 16 16 14 14 12 12 10 10 8 6 4 2 70000 60000 50000 40000 30000 20000 10000 1.5 1.5 1 0.5 70000 0.5 60000 50000 40000 30000 20000 10000 Distance from river month (meter) Distance from river month (meter) Fig 6.131 Maximum Salinity Concentration (psu) Salinity Concentration along Red River (scenario 3c) 104 Fig 6.132 Salinity Concentration along Thaibinh River (scenario 3c) Salinity Concentration (psu) 18 Salinity Concentration (psu) Maximum Salinity Concentration (psu) 18 Salinity Concentration(psu)er) 20 20 Salinity Concentration(psu)er) 60000 Distance from river month (meter) Maximum Salinity Concentration in Red River (Scenario 1a, 1b, 1c) Maximum Water Level in Red River (Scenario 1a, 1b, 1c) Salinity (psu) Salinity (psu) 13 13 26 26 12 12 24 24 LEGEND 11 11 22 10 10 22 Scenario 1a Scenario 1b 20 20 Scenario 1c 9 LEGEND Scenario 1b 18 16 16 14 14 12 12 10 10 Scenario 1a Scenario 1c Water Level (meter) Water Level (meter) 18 6 5 4 8 3 6 2 4 1 2 0 70000 65000 60000 55000 50000 45000 40000 35000 30000 25000 20000 15000 10000 240 220 200 180 160 140 120 100 80 60 40 20 Distance from river mouth (km) 5000 Distance from river mouth (meter) Fig 6.133 Maximum Water Level in Red River (scenarios: 1a, 1b and 1c) Fig 6.134 Maximum Salinity Concentration in Red River (scenarios: 1a, 1b and 1c) Maximum Salinity Concentration in Red River (Scenario 2a, 2b, 2c) Maximum Water Level in Red River (Scenario 2a, 2b, 2c) 13 13 12 12 Salinity (psu) Salinity (psu) 26 26 24 22 10 10 24 LEGEND 11 11 22 Scenario 2a Scenario 2b 20 20 Scenario 2c 9 LEGEND Scenario 2b 18 16 16 14 14 12 12 10 10 Scenario 2a Water Level (meter) Water Level (meter) 18 Scenario 2c 6 5 4 8 3 6 2 4 1 2 0 70000 65000 60000 55000 50000 45000 40000 35000 30000 25000 20000 15000 10000 240 220 200 180 160 140 120 100 80 60 40 20 Distance from river mouth (km) 5000 Distance from river mouth (meter) Fig 6.135 Maximum Water Level in Red River (scenarios: 2a, 2b and 2c) Fig 6.136 Maximum Salinity Concentration in Red River (scenarios: 2a, 2b and 2c) Maximum Salinity Concentration in Red River (Scenario 3a, 3b, 3c) Maximum Water Level in Red River (Scenario 3a, 3b, 3c) 13 13 12 12 11 11 Salinity (psu) Salinity (psu) 26 26 24 24 LEGEND 22 10 10 22 Scenario 3a Scenario 3b 20 20 Scenario 3c 9 LEGEND Scenario 3b 18 16 16 14 14 12 12 Scenario 3a Scenario 3c Water Level (meter) Water Level (meter) 18 6 5 10 10 4 8 3 6 2 4 1 2 0 70000 65000 60000 55000 50000 45000 40000 35000 30000 25000 20000 15000 10000 240 220 200 180 160 140 120 100 80 60 40 20 Fig 6.137 Maximum Water Level in Red River (scenarios: 3a, 3b and 3c) 5000 Distance from river mouth (meter) Distance from river mouth (km) Fig 6.138 Maximum Salinity Concentration in Red River (scenarios: 3a, 3b and 3c) 105 Maximum Salinity Concentration in Thaibinh River (Scenario 1a, 1b, 1c) Maximum Water Level in Thaibinh River (Scenario 1a, 1b, 1c) Salinity (psu) Salinity (psu) 2 3 1.8 1.8 2.8 2.8 LEGEND 2.6 2.6 Scenario 1a 1.6 1.6 1.4 1.4 2.4 Scenario 1b 2.4 2.2 Scenario 1c 2.2 1.2 1.2 1 LEGEND Water Level (meter) Water Level (meter) 0.8 0.8 Scenario 1a 1.8 1.8 1.6 1.6 1.4 1.4 1.2 1.2 1 Scenario 1b 0.6 0.6 Scenario 1c 0.4 0.4 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0.2 0.2 65000 0 90 80 70 60 50 40 30 20 10 0 60000 55000 50000 45000 Distance from river mouth (km) 40000 35000 30000 25000 20000 15000 10000 5000 Distance from river mouth (meter) Fig 6.139 Maximum Water Level in Thaibinh River (scenarios: 1a, 1b and 1c) Fig 6.140 Maximum Salinity Concentration in Thaibinh River (scenarios: 1a, 1b and 1c) Maximum Salinity Concentration in Thaibinh River (Scenario 2a, 2b, 2c) Maximum Water Level in Thaibinh River (Scenario 2a, 2b, 2c) Salinity (psu) Salinity (psu) 2 3 1.8 1.8 2.8 2.8 LEGEND 2.6 2.6 Scenario 2a 1.6 1.6 1.4 1.4 2.4 Scenario 2b 2.4 2.2 Scenario 2c 2.2 1.2 1.2 LEGEND 1 Scenario 2a Scenario 2b Water Level (meter) Water Level (meter) 0.8 0.8 Scenario 2c 1.8 1.8 1.6 1.6 1.4 1.4 1.2 1.2 1 0.6 0.6 0.4 0.4 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0.2 0.2 65000 0 90 80 70 60 50 40 30 20 10 0 60000 55000 50000 45000 Distance from river mouth (km) 40000 35000 30000 25000 20000 15000 10000 5000 Distance from river mouth (meter) Fig 6.141 Maximum Water Level in Thaibinh River (scenarios: 2a, 2b and 2c) Fig 6.142 Maximum Salinity Concentration in Thaibinh River (scenarios: 2a, 2b and 2c) Maximum Salinity Concentration in Thaibinh River (Scenario 3a, 3b, 3c) Maximum Water Level in Thaibinh River (Scenario 3a, 3b, 3c) Salinity (psu) Salinity (psu) 3 3 2.8 2.8 2.8 2.8 LEGEND 2.6 2.6 2.6 2.6 Scenario 3a 2.4 2.4 2.4 Scenario 3b 2.4 2.2 Scenario 3c 2.2 2.2 2.2 2 1.8 1.8 1.6 1.6 1.4 1.4 1.2 Water Level (meter) Water Level (meter) 1.2 LEGEND 1.8 1.8 1.6 1.6 1.4 1.4 1.2 1.2 Scenario 3a 0.8 Scenario 3b 0.8 0.8 0.8 0.6 0.6 0.6 0.6 0.4 0.4 0.4 0.4 0.2 0.2 0.2 1 Scenario 3c 65000 0 90 80 70 60 50 40 30 20 10 0.2 60000 55000 50000 45000 40000 35000 30000 25000 20000 15000 10000 5000 Distance from river mouth (meter) Distance from river mouth (km) Fig 6.143 Maximum Water Level in Thaibinh River (scenarios: 3a, 3b and 3c) Fig 6.144 Maximum Salinity Concentration in Thaibinh River (scenarios: 3a, 3b and 3c) 106 Fig 6.1 Fig 6.2 Fig 6.3 Fig 6.4 Fig 6.5 Fig 6.6 Fig 6.7 Fig 6.8 Fig 6.9 Fig 6.10 Fig 6.11 Fig 6.12 Fig 6.13 Fig 6.14 Fig 6.15 Fig 6.16 Fig 6.17 Fig 6.18 Fig 6.19 Fig 6.20 Fig 6.21 Fig 6.22 Fig 6.23 Fig 6.24 Fig 6.25 Fig 6.26 Fig 6.27 Fig 6.28 Fig 6.29 Fig 6.30 Fig 6.31 Fig 6.32 Fig 6.33 Fig 6.34 Fig 6.35 Fig 6.36 Fig 6.37 Fig 6.38 Fig 6.39 Fig 6.40 Fig 6.41 Fig 6.42 Fig 6.43 Fig 6.44 Fig 6.45 Fig 6.46 Fig 6.47 Fig 6.48 Fig 6.49 Discharge at Sontay Station March 5th – 15th, 2002 56 Discharge at Hanoi Station March 5th – 15th, 2002 56 Discharge at Tande Station March 5th – 15th, 2002 56 Discharge at Thuongcat Station March 5th – 15th, 2002 56 Discharge at Trieuduong Station March 5th – 15th, 2002 57 Discharge at Quyetchien Station March 5th – 15th, 2002 57 Discharge at Trucphuong Station March 5th – 15th, 2002 57 Discharge at Namdinh Station March 5th – 15th, 2002 57 Discharge at Catkhe Station March 5th – 15th, 2002 58 Discharge at Trungtrang Station March 5th – 15th, 2002 58 Water Level at Hanoi Station March 5th – 15th, 2002 59 Water Level at Ngodong Station March 5th – 15th, 2002 59 Water Level at Connam Station March 5th – 15th, 2002 59 Water Level at Vuthuan Station March 5th – 15th, 2002 59 Water Level at Balat Station March 5th – 15th, 2002 60 Water Level at Ninhbinh Station March 5th – 15th, 2002 60 Water Level at Docbo Station March 5th – 15th, 2002 61 Water Level at Tienhoang Station March 5th – 15th 2002 61 Water Level at Namdinh Station March 5th – 15th, 2002 61 Water Level at Trucphuong Station March 5th – 15th, 2002 61 Water Level at Binhhai Station March 5th – 15th, 2002 62 Water Level at Quyetchien Station March 5th – 15th, 2002 62 Water Level at TX Thaibinh Station March 5th – 15th, 2002 63 Water Level at Thuongcat Station March 5th – 15th, 2002 63 Water Level at Trieuduong Station March 5th – 15th, 2002 63 Water Level at Catkhe Station March 5th – 15th, 2002 63 Water Level at Cauphaohan Station March 5th – 15th, 2002 64 Water Level at Quankhai Station March 5th – 15th, 2002 64 Water Level at Trungtrang Station March 5th – 15th, 2002 65 Water Level at Tientien Station March 5th – 15th, 2002 65 Water Level at Banha Station March 5th – 15th, 2002 65 Water Level at Benbinh Station March 5th – 15th, 2002 65 Water Level at Caokenh Station March 5th – 15th, 2002 66 Water Level at Cuacam Station March 5th – 15th, 2002 66 Water Level at XMhoangthach Station March 5th – 15th 2002 66 Water Level at Donson Station March 5th – 15th, 2002 66 Sal Concentration at Balat Station March 5th – 15th 2002 67 Sal Concentration at Ngodong Station March 5th – 15th 2002 67 Sal Concentration at Tienhoang Station March 5th – 15th 2002 68 Sal Concentration at Binhhai Station March 5th – 15th 2002 68 Sal Concentration at Quankhai Station March 5th – 15th 2002 69 Sal Concentration at Cauphaohan Station, Mar 5th-15th 2002 69 Sal Concentration at Tientien Station March 5th – 15th 2002 69 Sal Concentration at Anphu station, March 5th – 15th 2002 69 Sal Concentration at Caokenh station, March 5th – 15th 2002 70 Sal Concentration at XMhoangthach station, March 5th – 15th 2002 70 Sal Concentration at Donson station, March 5th – 15th 2002 70 Discharge at Hanoi Station March 16th – 20th, 2002 71 Discharge at Tande Station March 16th – 20th, 2002 71 T T T T T T T T T T T T T T T T T T T T P P P T P P P T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T P P P T P P T P P P P P P P T P T P P P P T P T T P P P P P T P P P P P P T P T P T P P P P P P P P P P P P P P P P T P P P P P P T T P P P P T P T T P P P T T P P T T T T P P T P P P T P T P P P P P P T P T P P T T P P T T P T P T T T P T T T P P P P P T P P T P P P P T P P P T T P T P P P P T T P P P P P T T P P P T P P P P T T P P P P P P T T T P P P T P P P T P P T T T P P T P P P T P T P P P T P T P T T T P P T P P P P P T T T P P T P P P P T T P P P T T P P T P P P P T T P P P T P P P T P P P T T P P T P P P P T T P P T T P P T T T P P T P P T T P P P T P P T P T Fig 6.50 Discharge at Thuongcat Station March 16th – 20th, 2002 71 Fig 6.51 Discharge at Trieuduong Station March 16th – 20th, 2002 71 Fig 6.52 Discharge at Trucphuong Station March 16th – 20th, 2002 72 Fig 6.53 Discharge at Quyetchien Station March 16th – 20th, 2002 72 Fig 6.54 Discharge at Trungtrang Station March 16th – 20th, 2002 73 Fig 6.55 Discharge at Cuacam Station March 16th – 20th, 2002 73 Fig 6.56 Water Level at Hanoi Station March 16th – 20th, 2002 73 Fig 6.57 Water Level at Vuthuan Station March 16th – 20th, 2002 73 Fig 6.58 Water Level at Ngodong Station March 16th – 20th, 2002 74 Fig 6.59 Water Level at Connam Station March 16th – 20th, 2002 74 Fig 6.60 Water Level at Balat Station March 16th – 20th, 2002 74 Fig 6.61 Water Level at Trieuduong Station March 16th – 20th, 2002 74 Fig 6.62 Water Level at Ninhbinh Station March 16th – 20th, 2002 75 Fig 6.63 Water Level at Docbo Station March 16th – 20th, 2002 75 Fig 6.64 Water Level at Tienhoang Station March 16th – 20th, 2002 76 Fig 6.65 Water Level at Trucphuong Station March 16th – 20th, 2002 76 Fig 6.66 Water Level at Binhhai Station March 16th – 20th, 2002 76 Fig 6.67 Water Level at Quyetchien Station March 16th – 20th, 2002 76 Fig 6.68 Water Level at TX Thaibinh Station March 16th – 20th, 2002 77 Fig 6.69 Water Level at Cauphaohan Station March 16th – 20th, 2002 77 Fig 6.70 Water Level at Trungtrang Station March 16th – 20th, 2002 77 Fig 6.71 Water Level at Quankhai Station March 16th – 20th, 2002 77 Fig 6.72 Water Level at Tientien Station March 16th – 20th, 2002 78 Fig 6.73 Water Level at Banha Station March 16th – 20th, 2002 78 Fig 6.74 Water Level at Caokenh Station March 16th – 20th, 2002 79 Fig 6.75 Water Level at Cuacam Station March 16th – 20th, 2002 79 Fig 6.76 Water Level at XMhoangthach Station March 16th – 20th, 2002 79 Fig 6.77 Water Level at the Donson Station March 16th – 20th, 2002 79 Fig 6.78 Sal Concentration at Balat Station March 16th – 20th, 2002 80 Fig 6.79 Sal Concentration at Ngodong Station March 16th – 20th, 2002 80 Fig 6.80 Sal Concentration at Binhhai Station March 16th – 20th, 2002 81 Fig 6.81 Sal Concentration at Quankhai Station March 16th – 20th, 2002 81 Fig 6.82 Sal Concentration at XMhoangthach Station March 16th – 20th, 2002 81 Fig 6.83 Sal Concentration at Donson Station March 16th – 20th, 2002 81 Fig 6.84 Salinity Concentration along Red River in Different Case Study 84 Fig 6.85 Salinity Concentration along Thaibinh River in Different Case Study 84 Fig 6.86 15-day Average Upstream Flow with Various Scenarios 85 Fig 6.87 15-day Average Downstream Flow with Various Scenarios 86 Fig 6.89 Water Level along Red River 88 (scenario 1a) 88 Fig 6.90 Water Level along Thaibinh River (scenario 1a) 88 Fig 6.91 Salinity Concentration along Red River (scenario a) 88 Fig 6.92 Salinity Concentration along Thaibinh River (scenario a) 88 Fig 6.93 Hourly Averaged Flow Distribution in Estuaries (scenario 1b) 89 Fig 6.94 Water Level along Red River 90 (scenario 1b) 90 Fig 6.95 Water Level along Thaibinh River (scenario 1b) 90 Fig 6.96 Salinity Concentration along Red River (scenario 1b) 90 Fig 6.97 Salinity Concentration along Thaibinh River (scenario 1b) 90 Fig 6.98 Hourly Averaged Flow Distribution in Estuaries (scenario 1c) 91 T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T P P P P P P P P T P T P P P P P P T P P P P P P P T T P T P T P T P P P P P T P T P P P P T P P P P T P P P P T P P P P P T P P P T P P P P P P P P T T P P P P P P P P T T P P P P P P P T P P P P P P P P P T T P P P P P P T P P P T P P P T P P P P P P P P T P P P P P P P P P P P T P P P P P P P T P P T P P P P T T P P P P P T P P P T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T P T T T T Fig 6.99 Water Level along Red River 92 (scenario 1c) 92 Fig 6.100 Water Level along Thaibinh River (scenario 1c) 92 Fig 6.101 Salinity Concentration along Red River (scenario 1c) 92 Fig 6.102 Salinity Concentration along Thaibinh River (scenario 1c) 92 Fig 6.104 Water Level along Red River 94 (scenario 2a) 94 Fig 6.105 Water Level along Thaibinh River (scenario 2a) 94 Fig 6.106 Salinity Concentration along Red River (scenario 2a) 94 Fig 6.107 Salinity Concentration along Thaibinh River (scenario 2a) 94 Fig 6.108 Hourly Averaged Flow Distribution in Estuaries (scenario 2b) 95 Fig 6.109 Water Level along Red River 96 (scenario 2b) 96 Fig 6.110 Water Level along Thaibinh River (scenario 2b) 96 Fig 6.111 Salinity Concentration along Red River (scenario 2b) 96 Fig 6.112 Salinity Concentration along Thaibinh River (scenario 2b) 96 Fig 6.113 Hourly Averaged Flow Distribution in Estuaries (scenario 2c) 97 Fig 6.114 Water Level along Red River 98 (scenario 2c) 98 Fig 6.115 Water Level along Thaibinh River (scenario 2c) 98 Fig 6.116 Salinity Concentration along Red River (scenario 2c) 98 Fig 6.117 Salinity Concentration along Thaibinh River (scenario 2c) 98 Fig 6.119 Water Level along Red River 100 (scenario 3a) 100 Fig 6.120 Water Level along Thaibinh River (scenario 3a) 100 Fig 6.121 Salinity Concentration along Red River (scenario 3a) 100 Fig 6.122 Salinity Concentration along Thaibinh River (scenario 3a) 100 Fig 6.124 Water Level along Red River 102 (scenario 3b) 102 Fig 6.125 Water Level along Thaibinh River (scenario 3b) 102 Fig 6.126 Salinity Concentration along Red River (scenario 3b) 102 Fig 6.127 Salinity Concentration along Thaibinh River (scenario 3b) 102 Fig 6.128 Hourly Averaged Flow Distribution in Estuaries (scenario 3c) 103 Fig 6.129 Water Level along Red River 104 (scenario 3c) 104 Fig 6.130 Water Level along Thaibinh River (scenario 3c) 104 Fig 6.131 Salinity Concentration along Red River (scenario 3c) 104 Fig 6.132 Salinity Concentration along Thaibinh River (scenario 3c) 104 Fig 6.133 Maximum Water Level in Red River (scenarios: 1a, 1b and 1c) 105 Fig 6.134 Maximum Salinity Concentration in Red River (scenarios: 1a, 1b and 1c) 105 Fig 6.135 Maximum Water Level in Red River (scenarios: 2a, 2b and 2c) 105 Fig 6.136 Maximum Salinity Concentration in Red River (scenarios: 2a, 2b and 2c) 105 Fig 6.137 Maximum Water Level in Red River (scenarios: 3a, 3b and 3c) 105 Fig 6.138 Maximum Salinity Concentration in Red River (scenarios: 3a, 3b and 3c) 105 Fig 6.139 Maximum Water Level in Thaibinh River (scenarios: 1a, 1b and 1c) 106 Fig 6.140 Maximum Salinity Concentration in Thaibinh River (scenarios: 1a, 1b 106 and 1c) Fig 6.141 Maximum Water Level in Thaibinh River (scenarios: 2a, 2b and 2c) 106 Fig 6.142 Maximum Salinity Concentration in Thaibinh River (scenarios: 2a, 2b 106 and 2c) T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T Fig 6.143 Fig 6.144 and 3c) Maximum Water Level in Thaibinh River (scenarios: 3a, 3b and 3c) 106 Maximum Salinity Concentration in Thaibinh River (scenarios: 3a, 3b 106 T T T T T T T T S Da Table 6.1 Table 6.2 Table 6.3 Table 6.4 Table 6.5 Table 6.6 Table 6.7 Table 6.8 Table 6.9 Table 6.10 Table 6.11 Table 6.12 Table 6.13 Table 6.14 Manning Roughness Coefficient in main rivers of Red River Delta 54 Computed Statistical Parameters for Model Calibration 55 Salinity Concentration along Red River with Different Case Study 82 Salinity Concentration along Thaibinh River with Different Case Study 83 Hourly Averaged Flow Distribution in Estuaries 84 Hourly Averaged Flow Distribution in Estuaries (scenario 1a) 87 Hourly Averaged Flow Distribution in Estuaries (scenario 1b) 89 Hourly Averaged Flow Distribution in Estuaries (scenario 1c) 91 Hourly Averaged Flow Distribution in Estuaries (scenario 2a) 93 Hourly Averaged Flow Distribution in Estuaries (scenario 2b) 95 Hourly Averaged Flow Distribution in Estuaries (scenario 2c) 97 Hourly Averaged Flow Distribution in Estuaries (scenario 3a) 99 Hourly Averaged Flow Distribution in Estuaries (scenario 3b) 101 Hourly Averaged Flow Distribution in Estuaries (scenario 3c) 103 T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T ... prediction salinity intrusion in Red river delta Sonla Hydropower Plant is going to built in upstream of Da River to reduce flood damage and improve irrigation in the Red River Delta Increasing... The Red River Delta is in reality the delta of two river systems: the Red River System and Thai binh River System The Red River System consists of major river branches namely the Da, Lo and the. .. estuaries of the Red River System has drawn some primary remarks on the characteristics of salinity intrusion there Details of salinity intrusion in each tributary of the river network were not investigated