(Luận văn thạc sĩ) evaluation of water stress and water quality under the impact of climate change in the upper thai binh river basin, vietnam

VIETNAM NATIONAL UNIVERSITY, HANOI
VIETNAM JAPAN UNIVERSITY

HTET THU SOE

h

EVALUATION OF WATER STRESS AND
WATER QUALITY UNDER THE IMPACT
OF CLIMATE CHANGE IN THE UPPER
THAI BINH RIVER BASIN, VIETNAM

MASTER’S THESIS

 
 


VIETNAM NATIONAL UNIVERSITY, HANOI
VIETNAM JAPAN UNIVERSITY

HTET THU SOE

EVALUATION OF WATER STRESS AND
WATER QUALITY UNDER THE IMPACT
OF CLIMATE CHANGE IN THE UPPER
THAI BINH RIVER BASIN, VIETNAM
h
MAJOR: ENVIRONMENTAL ENGINEERING
CODE: 8520320.01

RESEARCH SUPERVISORS:
Associate Prof. Dr. SATO KEISUKE
Dr. PHAM QUY GIANG

Hanoi, 2021
 
 


ACKNOWLEDGEMENTS
Firstly, I would like to acknowledge Japan-ASEAN Integration Fund Scholarship
Program. Because of this scholarship, I got the opportunity to study Master’s Program
in VNU Vietnam – Japan University, Vietnam. I also thank the academic authority for
their effort to provide a continuous learning environment even in this global pandemic.
I would like to express my deepest gratitude to my principal supervisor, Associate
Professor Dr. Sato Keisuke. His research motivation, supervision and unique approaches
to each dimension played a critical role to raise these successful research outcomes. I
will never forget his kindness and gratitude in my life. I also would like to thank my cosupervisor, Dr. Pham Quy Giang who unwaveringly supported me to collect necessary
research data, including provision of research idea and encouragement.
My appreciation also extends to Ms. Pham Thi Kieu Chinh who assisted me to
complete research works. I could not have been completed without her kind supports. I

h

am also grateful to Assistant Professor Dr. Taishi Yazawa, for his invaluable research
advices.
I also would like to thank every single member of Master’s Program in
Environmental Engineering for their kind supports during these two years, from
enrollment to graduation.
Finally, yet importantly, my gratitude goes to my parents and soulmate who

always respect my decisions, and they had acted as my rock in times of troubles. Their
encouragement had been the crux of this research journey.
This research was financially supported by JICA Research Grant Program,
Ritsumeikan University and the Ministry of Education, Culture, Sports, Science and
Technology-MEXT/the Japan Society for the Promotion of Science-JSPS KAKENHI
Grant Program (JP 18H04153).
Thanks All!!

 
 


TABLE OF CONTENTS

 

h

CHAPTER 1: INTRODUCTION ................................................................................1
1.1. General Background.............................................................................................. 1
1.2. Research Motivation ............................................................................................. 3
1.3. Target Basin .......................................................................................................... 3
1.4. Problem Statements ............................................................................................... 4
1.5. Objectives .............................................................................................................. 5
1.6. Thesis Structure ..................................................................................................... 5
1.7. Baseline Information about the Study Basin......................................................... 6
1.7.1. Hydrological Features .................................................................................... 6
1.7.2. Topography and Administrative Boundaries .................................................. 7
1.7.3. Climatic Condition.......................................................................................... 7
1.8. Summary ............................................................................................................. 10

CHAPTER 2: LITERATURE REVIEW ..................................................................11
2.1. Administrative Provinces .................................................................................... 11
2.2. Hydrological Modelling ...................................................................................... 12
2.3. Climate Change ................................................................................................... 13
2.4. Water Stress Assessment..................................................................................... 15
2.5. Water Quality Evaluation .................................................................................... 17
2.6. Summary ............................................................................................................. 20
CHAPTER 3: HYDROLOGICAL SIMULATION .................................................21
3.1. SWAT Hydrological Model ................................................................................ 21
3.1.1. Preparation of In-put Data for Model Set-up ............................................... 23
3.2. SWAT Model Set-up........................................................................................... 29
3.2.1. Watershed Delineation ................................................................................. 29
3.2.2. HRU Analysis................................................................................................ 29
3.2.3. Integration with Weather Database.............................................................. 29
3.3. SWAT Model Calibration and Validation .......................................................... 30
3.4. Model Performance Evaluation........................................................................... 30
3.5. Results of Simulation .......................................................................................... 31
3.5.1. SWAT Model Calibration and Validation Result ......................................... 31
3.6. Summary ............................................................................................................. 35
CHAPTER 4: CLIMATE PROJECTION ................................................................36
4.1. Future Climate Scenario ...................................................................................... 36
4.2. Performance Analysis of Bias Correction Method ............................................. 38
4.3. Results of Climate Projection.............................................................................. 39
4.3.1. Performance Evaluation ............................................................................... 39
 
 


h

4.3.2. Projected Precipitation Data ........................................................................ 39
4.3.3. Projected Maximum and Minimum Temperature ......................................... 41
4.4. Summary ............................................................................................................. 45
CHAPTER 5: WATER STRESS ASSESSMENT ....................................................46
5.1. Water Demand..................................................................................................... 46
5.2. Water Resources .................................................................................................. 46
5.3. Water Stress......................................................................................................... 46
5.4. Future Water Stress ............................................................................................. 47
5.5. Result of Water Stress Assessment ..................................................................... 48
5.5.1. Current Water Demand ................................................................................ 48
5.5.2. Current Water Resource Potential ............................................................... 49
5.5.3. Current Water Stress .................................................................................... 49
5.5.4. Future Water Demand .................................................................................. 50
5.5.5. Future Water Resource Potential ................................................................. 51
5.5.6. Future Water Stress ...................................................................................... 51
5.6. Summary ............................................................................................................. 53
CHAPTER 6: WATER QUALITY EVALUATION ...............................................54
6.1. Water Quality Parameters ................................................................................... 55
6.2. Vietnamese National Water Quality Index (VN_WQI) ...................................... 56
6.2.1. Calculating WQI in this Study ...................................................................... 56
6.3. Data Analysis ...................................................................................................... 57
6.4. Result of Water Quality Assessment................................................................... 58
6.4.1. Water Quality Results ................................................................................... 58
6.4.2. Results of Statistical Analysis ....................................................................... 62
6.4.3 Results of Water Quality Index ...................................................................... 85
6.5. Future Water Quality Status under the Impact of Climate Change .................... 88
6.6. Summary ............................................................................................................. 89
CHAPTER 7: CONCLUSION, LMITATATIONS AND FUTURE TREND .......90
REFERENCES ............................................................................................................92
APPENDICES ..............................................................................................................99

Appendix 1. Result of Population Projection............................................................. 99
Appendix 2.A. Detailed Statistics About Current Water Stress .............................. 100
Appendix 2.B. Detailed Statistics About Future Water Stress ................................ 101
Appendix 3. Photo Records of River Water Sampling Point ................................... 102
Appendix 4. Scenes During River Water Sampling ................................................ 105
Appendix 5. List of Survey Team Member ............................................................. 105
Appendix 6. Analytical Methods ............................................................................. 106
Appendix 7. Detailed WQI Calculation Method...................................................... 110

 
 


LIST OF TABLES

h

Table 2.1. Variation of Precipitation (%) during 1958 – 2014 .....................................14
Table 3.1. SWAT Land Use Code and Statistics (2015) ..............................................26
Table 3.2. Summary for Preparation of Model Input-Data ..........................................28
Table 3.3. Model Performance Rating ..........................................................................31
Table 3.4. Goodness-of-fit Statistics for Discharge Simulation ...................................32
Table 3.5. Calibrated Parameters and Fitted Values.....................................................32
Table 3.6. Average Monthly Hydrological Components..............................................34
Table 3.7. Annual Water Balance Statistics .................................................................34
Table 4.1. Description of RCM ....................................................................................36
Table 4.2. Period of Study and Projected Climatic Variables ......................................36
Table 4.3. Performance Evaluation Results ..................................................................39
Table 4.4. Changes in Seasonal Precipitation ...............................................................40
Table 4.5. Changes in Seasonal Maximum Temperature .............................................42

Table 4.6. Changes in Seasonal Minimum Temperature ..............................................42
Table 4.7. Changes in Long Term Annual Temperature ..............................................43
Table 6.1. Location of River Water Sampling Points ...................................................54
Table 6.2. Summary of Water Quality Parameters .......................................................56
Table 6.3. VN_WQI Based Classification for Surface Water Quality .........................57
Table 6.4. In-situ Water Quality Result of Cau River Sub-basin .................................58
Table 6.5. Ex-situ Water Quality Result of Cau River Sub-basin ................................59
Table 6.6. In-situ Water Quality Result of Luc Nam River Sub-basin ........................60
Table 6.7. Ex-situ Water Quality Result of Luc Nam River Sub-basin .......................60
Table 6.8. In-situ Water Quality Result of Thuong River Sub-basin ...........................61
Table 6.9. Ex-situ Water Quality Result of Thuong River Sub-basin ..........................61
Table 6.10. Mean Values of Water Quality Parameters observed in CRSB ................62
Table 6.11. Mean Values of Water Quality Parameters observed in LNRSB..............63
Table 6.12. Mean Values of Water Quality Parameters observed in TRSB ................63
Table 6.13. Correlation Matrix .....................................................................................66
Table 6.14. Total Variance Explained for Wet Season of CRSB .................................67
Table 6.15. PCA Loadings (CRSB-Wet Season) .........................................................68
Table 6.16. Total Variance Explained for Dry Season of CRSB .................................70
Table 6.17. PCA Loadings (CRSB-Dry Season) ..........................................................71
Table 6.18. Total Variance Explained for Wet Season of LNRSB ..............................73
Table 6.19. PCA Loadings (LNSB-Wet Season) .........................................................74
Table 6.20. Total Variance Explained for Dry Season of LNRSB...............................76
Table 6.21. PCA Loadings (LNSB-Dry Season) ..........................................................77
Table 6.22. Total Variance Explained for Wet Season of TRSB .................................78
i
 


Table 6.23. PCA Loadings (TRSB-Wet Season) ..........................................................79
Table 6.24. Total Variance Explained for Dry Season of TRSB..................................81

Table 6.25. PCA Loadings (TRSB-Dry Season) ..........................................................82

h
ii
 


LIST OF FIGURES

h

Figure 1.1. Location of Target Basin (Source: TA-7629, VIE, 2012) ...........................4
Figure 1.2. Long Term Annual Maximum Temperature Trend .....................................8
Figure 1.3. Long Term Annual Minimum Temperature Trend ......................................8
Figure 1.4. Long Term Monthly Precipitation Trend .....................................................9
Figure 1.5. Average Monthly Discharge at the Gia Bay Hydrological Station (20052019) ................................................................................................................................9
Figure 1.6. Work Flow of the Research........................................................................10
Figure 2.1. Annual Changes of Temperature (Ngu et al., 2016) ..................................14
Figure 2.2. Water Stress Levels in Vietnam (2030WRG, 2017) ..................................17
Figure 2.3. River Water Quality in Vietnam (2030WRG, 2017) .................................20
Figure 3.1. DEM of the UPTBRB ................................................................................23
Figure 3.2. High Resolution Land Use and Land Cover Map of the UPTBRB (2015)
.......................................................................................................................................25
Figure 3.3. Major Land Cover Statistics in the UPTBRB ............................................25
Figure 3.4. Soil Map of the UPTBRB ..........................................................................26
Figure 3.5. The Proportion of Soil Classes observed in the UPTBRB ........................27
Figure 3.6. Location of Hydro-meteorological Stations ...............................................28
Figure 3.7. Formation of HRUs ....................................................................................29
Figure 3.8. Calibration Result at the Gia Bay Hydrological Station ............................33
Figure 3.9. Validation Result at the Gia Bay Hydrological Station .............................33

Figure 3.10. Annual Water Balance of the UPTBRB (2008 – 2019) ...........................35
Figure 4.1. Location of Projected Meteorological Stations ..........................................38
Figure 4.2. Average Monthly Precipitation Trends (5-stations average) .....................41
Figure 4.3. Annual Changes of Precipitation Trends (5-stations average) ..................41
Figure 4.4. Average Monthly Changes of Maximum Temperature (5-stations average)
.......................................................................................................................................43
Figure 4.5. Average Monthly Changes of Minimum Temperature (5-stations average)
.......................................................................................................................................44
Figure 4.6. Annual Changes of Maximum Temperature (5-stations average) .............44
Figure 4.7. Annual Changes of Minimum Temperature (5-stations average)..............45
Figure 5.1. Proportion of Sectoral Water Demand .......................................................49
Figure 5.2. Distribution of Current Water Stress Levels ..............................................50
Figure 5.3. Distribution of Predicted Water Stress Levels ...........................................52
Figure 5.4. Comparison of Current and Future Water Statistics (Annual)...................52
Figure 5.5. Changes in Water Demand by Each Sector ...............................................53
Figure 6.1. Location Map of Sampling Points..............................................................55
Figure 6.2. Eigen Values and Proportion of Variances (CRSB-Wet Season) ..............68
iii
 


h

Figure 6.3. Bi-plot Illustration for PC1 and PC2 in CRSB (Wet Season) ...................69
Figure 6.4. Bi-plot Illustration for PC2 and PC3 in CRSB (Wet Season) ...................69
Figure 6.5. Bi-plot Illustration for PC1 and PC3 in CRSB (Wet Season) ...................70
Figure 6.6. Eigen Values and Proportion of Variances (CRSB-Dry Season) ..............71
Figure 6.7. Bi-plot Illustration for PC1 and PC2 in CRSB (Dry Season) ....................72
Figure 6.8. Bi-plot Illustration for PC2 and PC3 in CRSB (Dry Season) ....................72
Figure 6.9. Bi-plot Illustration for PC1 and PC3 in CRSB (Dry Season) ....................73

Figure 6.10. Eigen Values and Proportion of Variances (LNSB-Wet Season) ............74
Figure 6.11. Bi-plot Illustration for PC1 and PC2 in LNRSB (Wet Season) ...............75
Figure 6.12. Bi-plot Illustration for PC2 and PC3 in LNRSB (Wet Season) ...............75
Figure 6.13. Bi-plot Illustration for PC1 and PC3 in LNRSB (Wet Season) ...............76
Figure 6.14. Eigen Values and Proportion of Variances for LNRSB (Dry Season) ....76
Figure 6.15. Bi-plot Illustration for PC1 and PC2 in LNRSB (Dry Season) ...............77
Figure 6.16. Eigen Values and Proportion of Variances (TRSB-Wet Season) ............78
Figure 6.17. Bi-plot Illustration for PC1 and PC2 in TRSB (Wet Season) ..................79
Figure 6.18. Bi-plot Illustration for PC2 and PC3 in TRSB (Wet Season) ..................80
Figure 6.19. Bi-plot Illustration for PC1 and PC3 in TRSB (Wet Season) ..................80
Figure 6.20. Eigen Values and Proportion of Variances (TRSB-Dry Season) ............81
Figure 6.21. Bi-plot Illustration for PC1 and PC2 in TRSB (Dry Season) ..................82
Figure 6.22. Bi-plot Illustration for PC2 and PC3 in TRSB (Dry Season) ..................83
Figure 6.23. Bi-plot Illustration for PC1 and PC3 in TRSB (Dry Season) ..................83
Figure 6.24. Cluster Dendrogram for Wet Season in the UPTBRB .............................84
Figure 6.25. Cluster Dendrogram for Dry Season in UPTBRB ...................................85
Figure 6.26. Seasonal Variation of Observed WQI in the CRSB ................................86
Figure 6.27. Seasonal Variation of Observed WQI in the LNRSB ..............................87
Figure 6.28. Seasonal Variation of Observed WQI in the TRSB.................................88

iv
 


LIST OF ABBREVIATIONS
CEM
CMIP6
CRSB
DEM
LNRSB

TRSB
PCA
RCP 4.5
RCM
SWAT
UPTBRB
VEA
WQI

:
:
:
:
:
:
:
:
:
:
:
:
:

Center for Environmental Monitoring
Coupled Model Inter-comparison Project Phase 6
Cau River Sub-basin
Digital Elevation Model
Luc Nam River Sub-basin
Thuong River Sub-basin
Principal Component Analysis

Representative Concentration Pathway under 4.5 Scenario
Regional Climate Model
Soil and Water Assessment Tool
Upper Thai Binh River Basin
Vietnam Environmental Administration
Water Quality Index

 
 
 

h

 
 
 
 
 
 
 

v
 


CHAPTER 1: INTRODUCTION
1.1. General Background
According to the Burmese proverb, “Rice offers survival for seven days; however,
water gives life only a day”. Not only human, none of a single living thing cannot survive
without water. Although water is a renewable resource, sound management and

adequate exploitation strategy are essential to ensure a sustainable water supply. In the
United Nation’s Sustainable Development Goal No. (6), target indicator (6.4) clearly
highlighted the critical role of water regarding the efficient use of water and water
scarcity (UNHCR, 2017).
Vietnam is rich in water resources with dense river networks accompanied by
2360 rivers. The river basins in Vietnam can be grouped into three main categories based
on the basin area and share of administrative boundary; multiple provinces, two
provinces and a single province (Taylor & Wright, 2001). There are 9 major basins
namely Red River, Thai Binh, Bang Giang – Ky Cung, Ma, Ca La, Thu Bon, Ba, Dong

h

Nai and Mekong that all shared together about 80% of the total country area (ADB,
2009). The average annual surface water runoff is approximately 830 – 840 bn m3 in
which only 43% is available for sustainable exploitation (2030WRG, 2017).
Groundwater potential accounts for 63 bn m3 but only 7% can be sustainably exploited
(FAO AQUSTAT, 2011). However, the sustainability of water resource in Vietnam is
greatly associated with the transboundary water management as 63% of total water
resources was originated in outside of the country; China, Cambodia, Lao PDR and
Thailand (MONRE, 2006 & 2030WRG, 2017).
Mekong and Red-Thai Binh are well known basins in Southern and Northern
Vietnam since they together contribute about 42% of the country GDP. In order to
sustain country GDP growth, the long term effective water resource management
strategies for these basins are crucial due to having their high trans-boundary water
dependency; 95% in Mekong and 40% in Red-Thai Binh Basin (2030WRG, 2017).

1
 

Vietnam is famous for agricultural business and that contributes 18% of the
country GDP but consumes about 80% of the total water share. One third of the country
area was occupied by agriculture in which 20.6% is available for farming, 12% is
identified as permanent crops and the permanent pasture mounts to 2.1% (2030WRG,
2017). Main crops are paddy, maize, coffee and sugarcane. Mekong delta, Red River
delta and Northern highland regions are serving as the rice bowls of Vietnam. According
to agricultural master plan (2020), the paddy fields will be maintained to not more than
3.8 million ha but the production is targeted to increase 41 to 43 million ton/year in 2020
and 44 ton/year by 2030 (MPI, 2016 & 2030WRG, 2017). It is highlighting that large
amount of water resources are required to meet the current and target production line.
Annual water demand in Vietnam is increasing year by year; 80.2 bn m3/year in
2009, 80.6 bn m3/year in 2015 and projected to reach 95 bn m3/year by 2030 (ADB,
2009 & IWRP, 2015). Water demand for agricultural sector is 76 bn m3 in 2016 and
expected to increase 91 bn m3 by 2030. Aquaculture demand is 10 bn m3/year in 2016
and forecasted to reach 12 bn m3/year in 2030. Annual industrial water demand is 6 bn
m3/year in 2016 and expected to increase 15.6 bn m3/year by 2030. Annual municipal

h

water requirement is 3.1 bn m3/year in 2016 and forecasted to increase 5.7 bn m3/year.
Hydropower sector demand is 57 bn m3/year in 2016 and projected to increase 63 bn
m3/year (2030WRG, 2017).
Wastewater treatment system is still under development in Vietnam. To elaborate,
current treatment system has the capacity to treat only 12-13% of municipal wastewater,
and 10% of industrial wastewater (Tien, 2015 & 2030WRG, 2017). Consequently, three
basins have been identified as the most polluted river basins; Cau River Basin, NhueDay River Basin and Dong Nai River Basin (MONRE, 2006). In 2015, with the purpose
to enforce the regulations on water resource management and quality control, “the
Ministry of Natural Resources and Environment (MONRE)” amended the technical
guidelines for surface water quality (QCVN 08: 2008/BTNMT). Currently, the MONRE
has been conducting regular water quality monitoring activity for Cau River Basin four

times a year and the results are disclosed to the public through the index score (Tran et
al., 2017).
2
 


Climate change is strongly linked with the watershed hydrology. By 2030, it was
estimated that the future annual runoff is expected to reach 15 bn m3/year where higher
runoff is predicted to increase 25 bn m3/year in wet season and lesser runoff in dry
season by 10 bn m3/year (2030WRG, 2017). It is showing the changes of rainfall pattern
on seasonal water availability. The major climatic variables such as precipitation and
temperature are greatly influencing the water resource sustainability.
Water demand and resources should be widely discussed considering potential
population growth, industry and agricultural aspects. Integrated approaches would be
more effective towards quantitative and qualitative development of water resources. It
is crucial to manage the existing water resources effectively to ensure safe and reliable
water supply required for multi-sectoral development.
1.2. Research Motivation
Red-Thai Binh plays a critical role in socio-economic development of Vietnam
as its contribution to the country GDP is approximately 15%. The basin possesses a
strategic geographical location for doing business ranging from high land mountain in

h

the North to alluvial plain land in North-East of the country. About agriculture, 15% of
total rice production comes from this basin serving as a promising resource for ensuring
national food security and foreign income. Numerous industrial clusters, craft villages
(i.e., 65% of the whole country) and intensive agricultural fields are concentrated in the
Red Thai Binh Basin (2030WRG, 2017). For the sake of people life and water resource
sustainability, the call for a comprehensive water resource exploitation plan was made

to the scientists and experts by Mr. Tran Hong Ha, the Minister for the Ministry of
Natural Resources and Environment (MONRE, 2016).
1.3. Target Basin
Target basin of the study is Upper Thai Binh River Basin (UPTBRB) located in
the Northern Vietnam. The UPTBRB is a component of Red-Thai Binh River Basin that
occupied almost the entire area of North East of Vietnam (See figure 1.1). Being a
transboundary river basin, the catchment area of Red-Thai Binh River Basin is
distributing in three countries; China (48%), Laos PDR (1%) and Vietnam (51%). The
basin provides 17% of total annual surface water runoff in Vietnam following after
3
 


Mekong River Basin with 59% thus play an essential role to provide the sufficient water
resources for the capital Hanoi (2030WRG, 2017).

h

Figure 1.1. Location of Target Basin (Source: TA-7629, VIE, 2012)
1.4. Problem Statements
The UPTBRB is having at high risk of water stress due to high water demand
from various sectors. According to the 2030 Water Resources Group, the overall water
demand in the Red-Thai Binh Basin is projected to increase 42% by 2030. Regarding
the water exploitation index, Red-Thai Binh Basin had been fallen under low water
stress category in 2016 and is expected to reach water stressed category by 2030. The
competition for a regular access to a steady supply of water share will be more
significant in the near future.
The UPTBRB is also highly vulnerable to the impact of climate change. The
projection statistics are highlighting that the average surface temperature under RCP 4.5
scenarios would increase 1.9 to 2.4°C by 2100. Similarly, the precipitation is expected

to increase 5 – 15%. The intensity and pattern of precipitation is expected to alter
depending on geographical characteristics (Ngu et al., 2016).
4
 


On the other hand, Cau river had long been identified as the most polluted
watershed in Northern Vietnam (Tran et al., 2017). Water quality evaluation in the Cau
River still remains challenges due to spatial and seasonal variation. Basin-wide water
quality assessment should be carried out in order to identify the pollution status
especially between the main rivers and tributaries. Likewise, the lack of water quality
database in the remaining two basins; Thuong and Luc Nam River Sub-basin still pose
the significant challenges for effective water resource management.
1.5. Objectives
The main objectives of this study are as below;
-

To evaluate basin water stress through integration of hydrological model and
social statistics

-

To evaluate basin river quality by multivariate statistical analysis and the
Vietnamese Water Quality Index

-

To contribute integrated water resource management through quantitative and
qualitative approaches

h

1.6. Thesis Structure

This thesis was prepared in a structure in compliance with the instructions for
preparation of Master’s thesis guidelines issued by Vietnam Japan University. General
research information with the corresponding chapters were summarized below;
 Chapter 1 is the general background about Vietnam relating to the status of water
resources. It briefs the current water demand by each sector including the efforts
of related bodies in water resource management. Significant water related
challenges are identified, and research objectives are proposed based on
motivation. Baseline natural and hydro-climatic information of the target basin
is also provided.
 Chapter 2 is mainly about literature review of research scope and content. It was
designed to provide the review of previous researches and important highlights
in the basin. The comparative studies which have a common research approaches
in other basins are widely discussed for referencing purposes.

5
 


 Chapter 3 describes about hydrological modelling in the basin. Detailed step by
step method to construct the watershed model, technical considerations and
results are provided.
 Chapter 4 summarizes climate projection part to predict the future climate
condition represented by regional climate model. Analysis and discussion are
made on the different time frames of historical, current and future scenario in
order to provide a comprehensive view of study on climate change in the basin.
 Chapter 5 discusses water stress through estimation of sectoral water demand and

resources. This session applied the outcomes of chapter 3 and 4 to determine
current and future water stress through integration of multi-assessment methods.
 Chapter 6 provides river water quality evaluation. Seasonal river water sampling
and laboratory analysis are performed. The results are driven by multivariate
statistical analysis and the Vietnamese regulations.
 Chapter 7 is a conclusion and recommendation session in which all the key
findings and necessary solutions are provided including limitations and future
research direction.

h

1.7. Baseline Information about the Study Basin
1.7.1. Hydrological Features
Upper Thai Binh River Basin (UPTBRB) is composed of three major rivers; Cau
River, Thuong River and Luc Nam River thus forming three sub-basins together. The
basin has a total number of 7 tributaries namely Cho Chu, Thuong Nghinh, Du, Cong
and Calo rivers in Cau River Sub-basin (CRSB), while Luc Nam River Sub-basin
(LNRSB) has one upstream tributary, Dinh Dem river and Thuong River Sub-basin
(TRSB) also has the only Rang tributary located in the upstream region. Cau River is
the longest river with 288 km and originated at Bac Kan Province. The length of Thuong
River is 157 km that is flowing from Lang Son Province to Bac Giang Province. The
length of Luc Nam River is 200 km and is serving as a blood line of Bac Giang Province.
All the three main rivers flow together into Thai-Binh River at the Pha Lai. The
UPTBRB is thus rich in river network and forming as a complex river basin that lies
completely inside the country boundary.
6
 


1.7.2. Topography and Administrative Boundaries

Geographic location of the basin extends from 21°48'54.81"N to 106°27'44.98"E.
The basin has an area of 12,720 km2, equivalent to about 4% of the total country area.
The upper part of the basin is surrounded by dense high mountain ranges extending
North-East direction. The highest recorded elevation is 1,592 m (Tam Dao Mountain)
while the lowest is 3.8 m at Pha Lai where Thai Binh river is formed. The low alluvial
plain land occupied the central and downstream for the basin that favors good conditions
for cultivation and settlement. The basin covers many administrative provinces such as
Bac Kan, Thai Nguyen, Hanoi, Vin Phuc, Bac Ninh, Lang Son and Bac Giang. As of
2015, the basin population is estimated at approximately 4.95 million. The average basin
population density is 389 persons per km2 that is higher than the country’s 280 person
per km2.
1.7.3. Climatic Condition
A tropical monsoon climate mainly dominated in the basin. The recorded current
long term annual maximum temperature is about 28 °C and 21°C is the minimum thus

h

the gap is about 6°C (See figure 1.2 & figure 1.3). The annual long term mean
precipitation account for approximately 1550 mm (See figure 1.4). There are four
seasons and each season lasts three months; winter (December to February), Spring
(March to May), Summer (June to August) and autumn (September to November)
(MONRE, 2006). The heaviest precipitation is mostly received in July and August with
the amount over 300 mm/month (Thai et al., 2017). During 2005 – 2019, about 67%,
two-third of total runoff, occurred within June to September of the rainy season (See
figure 1.5).

7
 

29.5

ANNUAL MAXIMUM
TEMPERATURE (°C)

29
28.5
28
27.5
27
26.5
26
2005 2006 2007 2008 2009 2012 2013 2014 2015 2016 2017 2018 2019
TIME (YEAR)

Figure 1.2. Long Term Annual Maximum Temperature Trend
22

21

h

ANNUAL MINIMUM
TEMPERATURE (°C)

21.5

20.5
20

19.5
19
18.5
200520062007200820092010201120122013201420152016201720182019
TIME (YEAR)

Figure 1.3. Long Term Annual Minimum Temperature Trend

8
 


ANNUAL PRECIPITATION (MM)

2400

2000

1600

1200

800
2005 2006 2007 200820092010201120122013 2014 2015 2016 2017 20182019

TIME SERIES

Figure 1.4. Long Term Monthly Precipitation Trend

h

200
180

Discharge (m3/s)

160
140
120
100
80
60
40
20
0
Jan

Feb

Mar

Apr

May

Jun
Jul
Month

Aug

Sep

Oct

Nov

Dec

 
 

Figure 1.5. Average Monthly Discharge at the Gia Bay Hydrological Station
(2005-2019)

9
 


1.8. Summary
It was clearly observed that the annual increase of water demand while water
resource availability is highly dependent on seasonal variation and also associated with
the impact of climate change. Moreover, limited water treatment facilities are
threatening river water quality along with the socio-economic growth. It is important to
evaluate the water resource in terms of quantitative and qualitative perspectives to let
the water stakeholders adopt the necessary practices and measures. The following figure
1.6 was designed to provide the corresponding approaches to achieve the specific
objectives.

h

Figure 1.6. Work Flow of the Research

10
 


CHAPTER 2: LITERATURE REVIEW
2.1. Administrative Provinces
Bac Kan
Bac Kan province is located in the dense mountainous region of Northern
Vietnam. As of 2013, it has a population of 303100 and population density is 64 persons
per km2. Agriculture is the major business but forest occupied the majority of the
province area. The climate is warm and temperate. High annual precipitation is received
in all year round, more than 2294 mm and the average annual temperature is 20.6 °C
(Child Fund, 2013).
Thai Nguyen
Thai Nguyen province is located in the center of North East Region. The province
area is 3526.64 km2 that exists together with Bac Kan Province in the North. In 2019, it
has a population of about 1.29 million while population density is 365 persons per km2.
The average temperature is 25 °C and the recorded average precipitation varies 2000 to

h

2500 mm. In 2010, industrial clusters were rapidly established thus the main economy
of the province had shifted to industry-construction from agriculture (Thai Nguyen
Overview, 2015).
Vinh Phuc
Vinh Phuc Province has the area of 1237.52 km2. As of 2013, the average
population is 1.03 million and population density is 832 persons per km2. The average
temperature is 24 to 25 °C while the average precipitation is 1650 mm. Agriculture is

the major business that shared about 70% of the total land area (Vinh Phu Statistics
Office, 2013).
Hanoi
Hanoi province is bordering the downstream of Cau River in the South of the
basin. The city is also located on the mouth of Red River and Da River. Being a
metropolitan city, the province has high population volume, 4.7 million, and 14639 per
persons km2 of population density over the total area of 319.56 km2. The average
11
 


temperature is 29.2 °C and the average precipitation is 1800 mm (Hanoi Geography,
2014).
Bac Ninh
Bac Ninh is located just 30 km North-East of the Capital Hanoi. The province
having 823 km2 can be recognized as the smallest province in Vietnam. The total
population is about 1.54 million in 2015 with 1676 persons per km2 population density.
The average recorded temperature is 23.6 °C and the average precipitation is 1926 mm.
Bac Ninh is famous for industrial hub especially foreign investment and trade (BAC
NINH Province - A Hi-Tech Development Hotspot, 2017).
Lang Son
Lang Son is a mountainous province that borders Quang Ninh Province in the
North and Bac Giang Province in the South, and Bac Kan Province in the West. The
province area is 8310 km2 with 831887 population (i.e., 102 population density) in 2009.
Forest and agriculture are the dominant land covers. The province is dominated by
tropical monsoon climate. The average recorded temperature varies 17 to 22 °C while

h

the average precipitation is approximately 1200 – 1600 mm (Lang Son Statistics Office,

2021).
Bac Giang
Bac Giang Province has 3895.59 km2 that borders Lang Son Province in the
North and Bac Ninh Province in the West. As of 2019, the total population is about 1.8
million with a population density of 483 persons per km2. It composed of 72% of the
mountainous districts. The average annual temperature is 23.3°C and the average annual
rainfall is 1915 mm. The industry-construction sector contributes the largest share of the
province GDP followed by agricultural sector (Wu. A., 2021).
2.2. Hydrological Modelling
Allaby & Allaby (1999) defined hydrological modelling as the process of
characterization of real hydrologic features and system with the integration of physical
models, mathematical equations and computer simulations. The model helps understand
watershed hydrology there by characterizing the runoff with respect to time especially
12
 


over the land and underground including the amount of water stored in the soil (Digman,
2002).
Depending on the requirements and physical principles, the hydrological model
can be mainly grouped into lumped and distributed models. The lumped model does not
consider spatial variability but distributed models divide the catchment into smaller units.
Static and dynamic model are also another classification based on time factors.
Empirical model (ANN), Conceptual model (HBV model and TOPMODEL) and
physically based model (MIKESHE, SWAT) are readily well known in hydrological
study (Devia et al., 2015).
Soil and Water Assessment Tool (SWAT) is one of the popular models to study
watershed hydrology in relation to climate change. SWAT has built a number of proven
hydrological researches, up to 36, in Vietnam (Tan et al., 2019). Tran et al. (2017)
simulated SWAT model whereas rainfall had a significant relationship with daily total

nitrogen load in the Cau River Basin. Thai et al. (2017) applied SWAT model in the Cau
watershed to study erosion and stream flow under the impact of climate change whereas

h

different pattern of soil loss and increased river discharge were predicted for the future.
Bui et al. (2019) used integrated SWAT and QUAL2K for water quality modelling to
overcome data scare challenges in the Cau watershed. Chuong et al. (2014) evaluated
water quality by SWAT model in Ta Trach watershed in central Vietnam. S. Shrestha et
al. (2018) coupled SWAT and climate model in the Songkhram River Basin, Thailand
to study climate and land use impact on hydrology and water quality. It was found that
the stream flow was associated with future climate and nitrate-nitrogen had a strong
relationship with land cover. S. Shrestha et al. (2016) investigated the water resource
potential under different time frames in the Indrawati River Basin, Nepal. This study
discovered that river discharge pattern and intensity was varied consistently with future
climate scenarios.
2.3. Climate Change
The significant climate change was already observed in Vietnam. Annual
temperature was increased by 0.62 °C during the period of 1958 – 2014 that is equivalent
to the increase of 0.1 °C by decade. The increase of 0.42 °C was observed within 1985
13
 


– 2014. In the North-East region, the increased days of maximum temperature greater
than 35 °C is observed during 1960 – 2014 (Ngu et al., 2016). The annual changes of
temperature were provided in figure 2.1. 

Figure 2.1. Annual Changes of Temperature (Ngu et al., 2016)
The slightly increased amount of precipitation was received in the country scale

h

but a decline annual precipitation ranging from 5.8 to 12.5 % in 57 years (1958 – 2014)
was observed in Northern Vietnam. But in South central and Southern regions, the
precipitation was increased to 19.8 from 6.9 % and 18.8% respectively. Regarding
seasonal variation, in table 2.1, a decreased pattern of precipitation was observed in the
autumn and the significant rainfall occurred during the spring in the North while winter
and spring tend to receive increased precipitation in Southern Vietnam (Ngu et al., 2016).  
Table 2.1. Variation of Precipitation (%) during 1958 – 2014
Climatic Regions
North-West
North-East
North-Delta
North-Central
South-Central
Central Highland
South

Spring
(MAR –
MAY)
+19.5
+3.6
+1.0
+26.8
+37.6
+11.5
+9.2

Summer
(JUN –
AUG)
-9.1
-7.8
-14.1
+1.0
+0.6
+4.3
+14.4

Autumn
(SEP –
NOV)
-40.1
-41.6
-37.7
-20.7
+11.7
+10.9
+4.7

Winter
(JAN –
FEB)
-4.4
+10.7
-2.9
+12.4
+65.8

+35.3
+80.5

Annual
-5.8
-7.3
-12.5
+0.1
+19.8
+8.6
+6.9
14
 


Climate change and future projection for Vietnam was developed using five
regional climate models; Weather Research and Forecast for climate projection (clWRF),
Providing Regional Climates for Impact Studies (PRECIS), Conformal Cubic
Atmospheric Model (CCAM), Regional Climate Model (RegCM), and Atmospheric
General Circulation Model/Meteorological Research Institute (AGCM/MRI). Long
term baseline period (1986 – 2005) was considered to forecast future climate change of
different centuries; the early term (2016 - 2035), middle term (2046 – 2065), and (2080
– 2099) as the ending period of 21st century (2080 – 2099). Overall, it was predicted that
under the RCP 4.5 scenario, the surface temperature tends to increase 1.9 – 2.4 °C and
precipitation would increase over 20% in the North (Ngu et al., 2016). In the midcentury under the RCP 4.5 scenario, the annual temperature would increase 1.6 – 1.7 °C
in which 1.2 – 1.6 °C in winter season, 1.3 – 1.6 °C in spring season, 1.6 – 2.0 °C in
summer, 1.6 – 1.9 °C in autumn. The average annual maximum and minimum
temperature tend to increase 1.7 – 2.7 °C and 1.4 – 1.6 °C. The winter rainfall tends to
decrease 10% in maximum, spring precipitation likely to increase 10%, summer rainfall
is expected to increase 5 - 15% and the autumn rainfall is likely to increase 15 – 35%.

h

In addition to these verifications, the climate change-based impact projections
indicated in the IPCC AR5 are the latest challenge. The current situation in the basin,
where the area is being developed for not only as the agricultural area but also as a
modernized industrial zone, makes it imperative to propose a sustainable water
resources policy and strategy.
2.4. Water Stress Assessment
There are a variety of methods to quantify the vulnerability of the basin in terms
of water stress. These are Falkenmark indicator, the Green-Blue Water Scarcity Index,
Water Stress Index, Smakhin Water Supply Stress Index, Stream flow-based index,
Water Scarcity Index, Water Supply Sustainability Risk Index, Watershed Sustainability
Index, Green Water Stress Index and Green Water Scarcity Index. Detailed technical
reviews were clearly described in the technical report of Xu and Hu (2017).
Water stress refers to those who do not have access to reliable and sufficient water
supply to meet their daily routine. Water scarcity can be defined as the region in which
15