Thesis of master degree: Optimal reservoir operation for water supply in dry season: the case study of Cua Dat reservoir in the Chu Ma river system Thanh Hoa province

Optimal reservoir operation for water supply in dry season: thecase study of Cua Dat Reservoir in the Chu - Ma river system Thanh Hoa province Master of science thesi This research is fi

MINISTRY OF EDUCATION AND MINISTRY OF AGRICULTURE AND

TRAINING RURAL DEVELOPMENT

Optimal reservoir operation for water supply in dry season: the

case study of Cua Dat Reservoir in the Chu - Ma river system

Thanh Hoa province

Master of science thesi

This research is finished for the partial fulfillment of requirements for she Master of science

degree at Thuy Loi University, Ha Noi, Vietmam

(This Master Programme is supported by NICHE-VNM106 project)

T hereby certify that the work which is being presented in this thesisentitled, “Optimal reservoir operation in dry season: the case study of Cua Dat

Reservoir in the Ma-Chu River system, Thanh Hoa province” in partial

fulfillment of the requirement for the award of the Mater of Scie 1 on IntegratedWater Resource Management, is an authentic record of my own work eartied outunder supervision of Dr, Nguyen Mai Dang

‘The matter embodied in this thesis has not been submitted by me for theaward of any other degree or diploma,

Date: 122014

Water supply of reservoirs and especially reservoirs used for irrigation,hydropower, aquaculture, navigation, environment in the dry season are oftentroubled due to increasing water demands according to the economic development andsociety, while the flow to the reservoir is limited In recent years, the depletion of theriver flow during the dry season occurs more frequently and at a more intense levelThis is partly due to forest coveray reduction in the upstream of river basins, andpartly due to the effects of climate change

Hence, computation of the optimum water supply of reservoir for the waterdemands in the dry season is needed, This study presents the

applying Fuzzy Logi

season of 2011-2012 of the Cua Dat Reservoir in the Chu River basin, Thanh Hoa

tial research onAlgorithm for optimal operation of water supply in the dry

province The Cua Dat Reservoir is a multi-purpose reservoir for the following tasks:flood prevention, water supply, iigation, power generation, and environmental flows

In addition, MIKE 11 model is also used to simulate the release from the reservoir tothe downstream to evaluate the efficiency of the optimal method

‘The research used Fuzzy Logic algorithm based on the rule, the principle of "IF

- THEN" and built the membership functions for the input variables: water level,inflow to the reservoir, the water demands, and discharge from the reservoir It isdeveloped for the Fuzzy operating systems [or the Cua Dat Reservoir and is meant 10determine the optimal discharge process in case of shortage of water in the dry seasonInflows, releases and water levels of the Cua Dat Reservoir were collected from actualoperation of the reservoir, For water demand of stakeholders, the author determined

that the (otal water demand for whole area was about 4547 Mi.m’, For hydropower

based energy production water is used at the largest rate (67% of total water demand),

while domestic purposes water is obtained smallest rate of water use of the Cua Dat

Reservoir

Finally, the results from optimal method, the reservoir can meet 80% of waterdemand more than actual release throughout the dry season of 2011-2012 The initialresearch has been successfull and the results showed that this method can be applied

‘well to the optimal reservoir operation in Vietnam

Key words: Cua Dat, reservoir operation, optimization, Fuzzy Logic, water

rule, MIKE 11 model

demand, Fusz

Trình Xuan Manh

MSc Thesis:

First of all, I would like to give a big thank to all people who have supportedand assisted me during the Master ‘Thesis Research Thanks for their support,

‘encouragement and guidance that allowed me to complete Ì study in time,

Especially, I would like to express my appreciation to Dr Nguyen Mai Dang,

my supervisor, for his unfimited encouragement, guidance, comments and technicalsupports on the Fuzzy Logic approach and other models as well as the thesis writingprocess from the beginning ofthe thesis research.

1 would like to thank NICHE-VNM-106 project from the Government of theNetherlands for their financial support during the MSc study in the ThuyLoiUniversity I thank to Mrs, Hoang Nguyet Minh and Mrs Vu Thi Thuy Ngan whomade a linkage between me and NICHE I also would like to thank Assoc Prof DrNguyen Thu Hien, Dean of the Faculty of Water Resources ngineering, for her helpand comments during the Master study in the ThuyLoi University

Masi, and Ms

I wish to thank Dr Ilyas Martine Rutten for their feedback,references and support from the proposal process

1 also wish to thank Mrs Mariette Van Tilburg, my English teacher, for her

‘comments and support from the final thesis report

1 also want to thank the ThuyLoi University (TLU), Song Chu Irrigation

‘Company, National center for Hydro-Meteorological Service (HMS) for providing me

very useful data sets

“Thanks to all of my colleagues at the HaNoi University of Natural Resourcesand Environment in Vietnam for your assistance in the last two years You will alwaysbbe in my mind

Last but not least, T want to take this opportunity to show my appreciation to myfamily, my close friends for their inspiration and support throughout my life: thisresearch is simply impossible without you

Trình Xuan Manh

MSc Thesis:

Table of Contents

CHAPTER I: INTRODUCTION

1.1 Background

L2 Problem statement

13, Objectives and Res

13.1, Objectives of the study

(CHAPTER II: LITERATURE REVIEW

ILL Studies on reservoir operation tự

112 Fuzzy logic theory

113 Overview of hydraulic and hydrological modeling,

IL4 MIKE model "

ng optimal theory

CHAPTER IIL: THE STUDY AREA s-5-55555<sssssececeee Td

TILL, Description of the study area BTILL.1 Location of the study area B

TH L.2 River network, 4I1L.1,3 Topographical characterises 16IHL.1.4 Geological, land and vegetable characteristics 18MIL2 Climate and hydrological condition 18THL2.1 Climate condition 18THL2.2 Hydrological condition 23H13 Population and economic characteristies 23TI13.1 Population of the study area 2311.3.2 Economic characteristics 24UIL4 Description of the Cua Dat Reservoir

CHAPTER IV: DATA AND METHODOLOGY

IV.1 Data collection 29

IV.1.1 Meteorological data 30IV.1.2 Hydrological data 32IV.1.3 Cua Dat reservoir operation data 34IV.1.4 Determining total water demand 35TV.2 Optimal analysis and Fuzzy logic approach for Reservoir operation 50TV.2.1 Methods using in optimal reservoir operation 50IV.2.2 Objective functions and constrain 331V.2.3 Using Fuzzy logic technique to optimize the Cua Dat reservoir operation54IV.3 Hydraulic and hydrological model setup 62IV.3.1 Determination of the model inputs 621V.3.2 Model setup 6IV.3.3 Model calibration and validation 65

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CHAPTER V: RESULTS AND DISCUSSIONS.

V.1 Optimizing the Cua Dat reservoir operation

V.2 Routing the release to the downstream

CHAPTER VI: CONCLUSIONS AND RECOMMENDATIONS.VII Conclusions

List of FiguresFigure 2-1: Relationship between the various representations of a model 10Figure 3-1: Location of study in the Thanh Hoa province in Viet Nam 13Figure 3-2: Ma ~ Chu River Network in Viet Nam 16

Figure 3-3: Digital Elevation Model (DEM) of Thanh Hoa province 17

Figure 3-4: The location of the Cua Dat Reservoir on Ma-Chu river system 26Figure 3-5: The main dam of the Cua Dat Reservoir 28Figure 3-6: The spillway of the Cua Dat Reservoir 28Figure 3-7: The storage of the Cua Dat Reservoir 28

Figure 3-8: The intake (ower of the Cua Dat Reservoir 28

Figure 3-9: The gate of spillway of the Cua Dat Reservoir 28

Figure 3-10: The Bai Thuong weir 28

Figure 4-1: Distribution of monthly rainfall pattern at Thanh Hoa station 30Figure 4-2: Distribution of monthly air temperature at Thanh Hoa station 31

Figure 4-3: Distribution of monthly average evaporation at Thanh Hoa station in 2011

& 2012 31Figure 4-4: Distribution of relative humidity at Thanh Hoa station in 2011 & 2012.32Figure 4-5: Annual discharge of the Cam Thuy and Cua Dat station 33

Figure 4-6: Schematization of hydrological station network 34

Figure 4-7: Monthly average discharge of Turbin of hydropower plant in years of

2011, 2012 and 2013 35

Figure 4-8: Inflow discharge of the Cua Dat reservoir in 2011 and 2012 35Figure 4-9: Seasonal period and chart of water requirement of Spring paddy in 2011 39Figure 4-10; Seasonal period and chart of water requirement of winter paddy in 2011

At

Figure 4-11: Seasonal period and chart of water requirement of sugar cane in 2011.42

Figure 4-12: Water use structure of whole downstream area of the Cua Dat reservoir in

2011 48Figure 4-13: General flow chart of optimal reservoir operation in dry season, 52Figure 4-14: Fuzzy inference system for Fuzzy Mamdani 56Figure 4-15: Transformation of input variable to membership value 5Figure 4-16: Membership function for reservoir level for Fuzzy Mamdani model 58

Figure 4-17: Membership funetion for inflow for Fuzzy Mamdani model 5g

Figure 4-18: ship function for water demand for Fuzzy Mamdani model 59

Figure 4-19: n for release for Fuzzy Mamdani model 59

Figure 4-20: ‘base for operation of Cua Dat reservoir 60

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MSc Thesis:

Figure 4-21: Process of application, implication and aggregation 61Figure 4-22: Hydraulic network of the Ma ~ Chủ river basin 65Figure 4-23; Observed and simulated hydrograph at Cua Dat station in 2006 67Figure 4-24: Observed and simulated hydrograph at Cua Dat station in 2008 68

Figure 4-25: Observed and simulated hydrograph of water level at Ly Nhân Station in

2006, 60

Figure 4-26: Observed and simulated hydrograph of water level at Xuan Khanh Station

in 2006 60Figure 4-27: Observed and simulated hydrograph of water level at Giang Station in

2006 0Figure 4-28: Observed and simulated hydrograph of water level at Ly Nhan Station in

2008 nFigure 4-29: Observed and simulated hydrograph of water level at Xuan Khanh Station

in 2006 m1Figure 4-30: Observed and simulated hydrograph of water level at Giang Station in

2006 7Figure 4-31; Structure of fuzzy system for Cua Dat reservoir 73Figure 4-32: Comparison of water demand and fuzzy and actual releases ”“

Figure 5-1: Hydrograph of optimal operation atthe Bai Thuong weir 75

Figure §-2: Hydrograph of optimal operation at the Xuan Khanh station 75Figure 5-3: Hydrograph of optimal operation at the Giang station 76

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MSc Thesis:

List of Tables

‘Table 3-1: Distribution of natural areas according to provincial border of the Ma riverbasin (ha) 14

‘Table 3-2: Characteristics of river shape of some large tributaries 15

‘Table 3-3: Average annual rainfall for many years at some stations of the Ma river

basin 19

‘Table 3-4: Annual rainfall characteristics 20

‘Table 3-5: Monthly and annual wind speed at some stations of the Ma river basin (mm/s)

2t

‘Table 3-6: Average monthly temperature for many years at some stations, 2

‘Table 3-7: Monthly average evaporation of some stations of the Ma River Basin 22

‘Table 3-8: Some main parameters of the Cua Dat Reservoir 25

Table 4-1: Kinds of data have been used in the study 29

‘Table 4-2: Crop distribution of different cultivated area in downstream of the Cua Dat

reservoir 36

‘Table 4-3: Plant coefficients of paddy 39

‘Table 4-4: Plant coefficients of other plants 39

‘Table 4-5: Water requirement of Spring paddy in 2011 40

‘Table 4-6: Water requitement of winter paddy in 2011 4i

‘Table 4-7: Water requirement of sugar cane in 2011 42

‘Table 4-8: Monthly water demand of agriculture of whole area in the Cua Dat reservoirdownstream in 2011 44

‘Table 4-9: Water demand of industrial production at downstream of the Cua Dat

reservoir 45

‘Table 4-10; Domestic water demand of downstream area 46

‘Table 4-11: Structure of water use of whole area in 2011 48

‘Table 4-12: Water demands and inflows in ten-day period in 2011, 49

‘Table 4-13: List of tributary basin on the Ma ~ Chu river basin “Table 4-14: Results of MIKE L1HD model calibration at Ma-Chu river basin in 2006

70Table 4-15: Results of MIKE 1IHD model validation at the Ma-Chu river basin in

2008 T2

Table 4-16: The NASH for caleulation of alternatives 74

‘Table 5-1: Flow characteristics at the Chu River downstream using optimal operation

76

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MSc Thesis:

CHAPTER INTRODUCTION

LL Background

Reservoi play an important role in the development of many countries.Nowadays, there are many reservoirs and dams which were built in many developingcountries for various purposes, for example, water supply, flood control, electric

‘generation, environment and re ation However, in 18" Century reservoirs were

built to supply water, flood control and navigation as the main purposes, after thatreservoirs were built for hydropower generation purpose by increasing demand forenergy consumption of human

[As mentioned above, most of reservoirs are used for multiple-purpose All

those purposes need to be satisfied but the capacity of reservoir is limited For thisreason some conflicts may happen among the water users who have other interests andconflicts also may happen in reservoir itself For hydropower generation, higherstorage of water is needed, on the contrary, much water should be relaesed forcultivated areas in dry season especially Besides this, there are also many otherconflicis in user factors such as transportation and hydropower generation, flood

control and environment

Vietnam has many big river networks with nine major river basins spread alongthe country At present, many multipurpose reservoirs were built to serve the socio-economic issues such as Cua Dat, Hoa Binh and Dau Tieng Reservoir ete Themanagement and operation for many purposes are really difficult On the other hand,the operation of each reservoir is a challenge for management and operators, Reservoir

‘operation is needed to balance efficiently interests of water users and satisfy constraintsystems aim to get maximum interests An optimal policy is necessary to accomplishthe problem objective and rule curve is one of appropriate methods to determine

‘operation policy of reservoir Reservoir operation policy spe‹ es the eriteria to retain

‘or release water in or from a reservoir at different times of the year depending upon theinflows and demands

Trình Xuan Manh

MSc Thesis:

Optimization model used the mathematical programming technique to find thebest possible solution based on a specific performance function and some physicalconstraints, Mathematical programming includes several techniques such as dynamicprogramming (DP), nonlinear programming (NLP), linear programming (LP), geneticalgorithms (GAs) and optimal control theory (OCT) (Hirad and Ramamurthy 2000)

Within the development of soft computing technique, optimal technique hasbeen used in number water resources issues In this thesis, the author will use Fuzzytechnique combine with hydraulic model to develop an operation policy for multi-purpose reservoir in an efficient way

1.2 Problem statement

Ma river basin is located in North-West region of Vietnam, it bordering Laos onthe West The upstream basin is located in Vietnam, the middle basin is located in Laosand the downstream is located in Vietnam, Accordingly, Ma river basin is an

international basin, The catchment area of Ma river basin is about 31.060 KmẺ of which that in Vietnam is 20.190 Km? (IWRP 2003) The Chu River is a main tributary

of the Ma River Itis located in the downstream area (IWRP 2003),

Based on potential water resources of this river system, many kinds of reservoirsuch as single purpose and multi-purpose were built on the main river of the Ma riversystem The Cua Dat Reservoir is one of the biggest projects related to water resourceprojects in Thanh Hoa province, The Cua Dat Reservoir is ä multi-purpose reservoir

‘Those purposes include as: to reduce flood peak and protect downstream area due toprobability of flood of 0.6% and control water level in downstream area at Xuan Khanh.station on the Chu river (under 13.71m) in high flow season; To supply discharge of

7715 mỖ% for domestic and industrial water demand; To irrigate about 86.862 hacultivated are To generate electricity with capacity of 97 MW; To prevent salt waterintrusion lower than 1%e at Ham Rong measured station (MARD 2013)

[As mentioned above, the Cua Dat Reservoir has purposes are to supply water forsome water users such as hydropower generation, agriculture, industry, domestic andenvironment However, in dry season the increasing water demand of water us 8 is

‘one of the important problems within water shortage in this river basin due to lessrainfall will enhance the conflicts among all the factors In order to balance different

Trình Xuan Manh

MSc Thesis:

Water interests and solve the problems which related to using water, the Cua Datreservoir needs to optimize reservoir operation

13 Objectives and Research questions

13.1 Objectives of the study

“The main objectives ofthis research are

~ To optimize operation of the Cua Dat Reservoir in dry season, Thanh Hoa province

by using simulation model (MIKE 11 model) and optimal model (Fuzzy LogieTechnique)

‘To provide management recommendations or alternatives and suggest appropriatemethod of operation of the Cua Dat Reservoir in the Ma ~ Chủ river basin

1.3.2 Research Questions

1 What is Fuzzy logic theory and how to apply fuzzy loại in reservoir operation?

2 How to balance the water demand and water interests of the stakeholders in

‘operation of the Cua Dat Reservoir?

3 What are the objective functions and constraints in operation of the Cua DatReservoir?

4 Does the Cua Dat Reservoir supply enough water for all of sectors in downstream

‘area regarding to current scenarios?

1.4 Structure of the thesis

This thesis structure includes those parts as below

Chapter 1: This chapter disc ses an overview of the study, the problemstatement and the objective of the study are presented

Chapter 2: This chapter reviews several researches of optimal reservoiroperation, Overview of hydrological model and optimization formulation arepresented, MIKE L1 model also is briefly introduced inthis chapter

Chapter 3: This chapter presents natural characteristic, natural conditions of thestudy as well as population and economic characteristics of the study Moreover, thischapter also briefly introduces characteristics of the Cua Dat Reservoir and waterdemand of each water user in downstream area

Chapter 4: This chapter describes all kind of data collection and data analysisWhich are used in this study In this chapter, the author also shows the results of data

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MSc Thesis:

calculation as the input of hydrological modeling and calculating water demand of each,

‘water user in the downstream area This chapter determines the objective functions andall of constraint systems in the Cua Dat reservoir as well as using optimization model

to determine optimal rule curve (standard rule curve) Hen the author also presentsMIKE 11 model set up for calibration and validation model and the results of routingflow from the Cua Dat Res voir by MIKE 11 model inthis chapter

‘Chapter 5: The results of optimal model and simulation model are shown in thischapter through figures and evaluation tables The chapter also analyzes the resultsfrom two models in order to achieve the objectives ofthe study

Chapter 6: This chapter also focuses on the main performances, conclusions andrecommendations for future studies

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CHAPTER I LITERATURE REVIEW Studies on reservoir operation using 0} al theory

Optimization is scientific field about best choice in some possible alternatives.Optimal theory has been developed and investigated for many years over the word.Optimization has been applied to a lot of fields in human life Especially, in waterresource issues are used optimal theory as one of the effective tools for managementand decision making Furthermore, optimization techniques have become increasingly

important in management and operations of complex reservoir systems In reservoir

management, a lot of researchers have developed reservoir optimal operation duringthe past four decades using dynamic programming (DP), linear programming (LP),nonlinear programming (NLP), etc (Cheng etal 2008),

Rama and Sharad (2009) have developed operation policy for multi-purposereservoir in India using Neuro — 2y technique including Fuzzy Mamdani and

ANFIS (Adaptive Neuro Fuzzy Interactive system) Their research determined

‘operation policy for monsoon period and non-monsoon period of Ramganga reservoirand optimum releases against demands for domestic supply, irrigation and hydropowergeneration In other research, Omid et al (2008) used optimal algorithm (HBMO-Honey Bee Mating Optimization) for single and multi-purpose reservoir to minimizethe total present net cost of the system and maximum possible ratio for generateclectricity with installed capacity In a case study of Hirakud Reservoir in Mahanadibasin, India, D.Nagesh Kumar etal (2009) used Folded Dynamic Programming (FDP)

to develop a long -term optimal operation policies for flood control He shoved thatFDP is a new search technique which can take care of all difficulties of other methods

to certain extend faced

Long N.L et al 2007) presented successfully a method as a tool for optimizing

‘operation of reservoir by using a combination of the simulation model and optimal

model The authors optimized control strategies for the largest reservoir in Vietnam,

Hoa Binh Reservoir, in order to neutralize the conflicts in regulating water betweenflood control and hydropower generation The authors also organized two mainpurposes in the flood season, With simulation model, they used MIKE 11 to guide the

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MSc Thesis:

releases of the reservoir system according to the current storage level, the meteorological conditions, and the time of the year Afterward, the shuffled complexevolution (St E) algorithm was chosen as a perfect tool for optimizing the reservoir

hydro-operation Babel et al (2011) analyzed that the tradeoff between hydropowerproduction and environmental flow requirements for the hydropower system and theimpact of alternative scenarios of a hydropower system operation on ei gy productionand natural flow regime in the La Nga river basin in Vietnam The authors usedGifferent alternative operation policies to simulate the system by the Range ofVariability Approach (RVA) method Hirad and Ramamurthy (2000) showed a newcomposite algorithm as an alternative model to solve the problem related to the size ofreservoir when operating policy of multi-reservoir systems is applied based onPontryagin's minimum principle

Genetic algorithms have been widely applied in optimization to solve waterresources system Cheng et al (2008) used Chaos Genetic Algorithm (CGA) which

‘based on the Chaos Optimization Algorithm (COA) and Genetic Algorithm (GA) toapply to the global optimum of the Resenbrock function, the Schaffer function and the

‘optimal operation of hydropower station reservoir M Habe Y Nagayama (2002)

used Neural Network and Fuzzy System to optimize multi-purpose Dam of flood andnon- flood seasons Base on their results, the fuzzy system is an effective operationsystem when the major objective is water use, Besides that Network Fuzzy System iseffective for flood control In other research, fuzzy mathematical programming wasused in research of Jairaj and Vedula (2001), their study area isa three reservoir system

in the upper Cauvery river basin, south China, As the results illustrated that, use offuzzy linear programming in multi-teservoir system optimization presents a potentialalternative to get the steady state solution with less efforts than classical stochasticdynamic programming (Jairaj and Vedula 2001) Panigrahi and Mujumdar (2000) alsoused Fuzzy Logie in their study to reservoir operation modeling, the case study of theMalapribha irrigation reservoir in Karnataka, India

Besides that, there are many researches in reservoir operation in Vietnam Theyalso used many optimization and simulation methods Nghia TT (2009) usedcombination method between optimization and simulation model within advanced tools

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such as hydraulic dynamic model MIKE 11 and optimal technique GAMS Theresearch had three major contents as follow: i) Determining water demand of waterusers (such as Industry, Agriculture, Navigation and Environment); ii) Determiningupstream constraints of system due to periods; i) Propose the operation process forthree reservoirs including Thac Ba, Hoa Bình, Tuyen Quang based on optimalcalculation in order to ensure that multi-eservoir can supply enough water for waterrequirements in downstream, Hung N.T et al (2010) proposed models for optimal

‘operation of multiple purpose reservoir The research proposed three distinctalternatives including: i) Reservoir has mutual purpose for irigation and hydropower,ii) Reservoirs major purpose is hydropower generation and second is irrigation; ii)Reservoir has major purpose is irrigation and hydropower generation is second Based

‘on models of the authors were built by using Delphi programming language andapplied Dynamic programming The models were applied on Dinh Binh Reservoir(Bình Dinh province) and A Vuong Reservoir (Quang Nam province) In otherresearch, optimization and simulation method were also used in the research of Tuyen

‘MH (2009) for supplying water in dry season of reservoir system on Huong River

basin, The research combined GAMS optimization model and MIKE 11 hydraulic

dynamic model to control flow in downstream The author illustrated thatenvironmental flow is about 31,5 mŸS in location of Thao Long Weir thoughout GAMS

‘optimal model In dry water year with probability of 90%, the reservoir system can stillcensure the lowest discharge into dowstream area is 75mÖ

Finally, optimization theories have been applied in a number of water resourcesissues, especially in reservoir operation Fuzzy logic technique is one of the useful

‘optimal tools for supporting reservoir operation and decision making Using

ch are common over

‘optimization and simulation models in reservoir operation re

the world However, the Fuzzy Logic theory has been never applied in any researchabout reservoir operation in Vietnam That is reason in this research the Fuzzy theorywill be used as an optimization tool to optimize operation policy of Cua Dat Reservoir

‘thoughout objective function and constraints

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MSc Thesis:

11.2 Fuzzy logic theory

‘According to Rama and Sharad 2009, the Fuzzy logic is another area of artificialintelligence It has been applied successfully in different water resources applications

“The key content about fuzzy logic theory is tha it allows for something to be partly thisand partly that, rather than having to be either all this or all that The degree of

“belongings

number between 0 and 1.0 (Rama and Sharad 2008)

” to a set or category can be described numerically by a membership

In fuzzy logic theory, variables are “fuzzification” through the use of

‘Membership Function (MF) that defines the membership degree to fuzzy sets Thesevariables are called lingui variables A fuzzy subset A of a universe of discourse U

is characterized by a membership function j4(x) in the interval [0,1] and represents the

‘grade of membership in A (Rama and Sharad2009)

The fuzzy objectives and constraints are characterized by their membershipfunctions Membership functions are curves that define how each point in the inputspace is mapped to a membership value (or degree of membership) between 0 and I Itcan be of different forms including triangular, trapezium, Gaussian, B-spline, sigmoid

etc Membership function can be symmetrical or unsymmetrical (Rama and

‘Sharad2009)

Fuzzy rule base system can be used as a suitable representation of simple andcomplex physical systems, The fuzzy rule based model operates on an “IF-THEN”principle, where the “IP” is a vector of fuzzy explanatory variables or premises and

“THEN” is fuzzy consequence Fuzzy logic theory allows the user to captureuncertainties in data A fuzzy tool is available with the MATLAB software Two types

of fuzzy inference systems including: Mamdani type and Takagi Sugeno type

Fuzzy logic theory also has been used widely in modeling of reservoir

‘operation, According to Panigrahi and Mujumdar 2000 when applying fuzzy theoryneed (0 follow several steps: (a) Fuzzification of inputs, where the crisp inputs such asthe inflow, reservoir storage and release, are transformed into fuzzy variables, (b)Formulation of the fuzzy rule set, based on an expert knowledge bas , (€) Application

of a fuzzy operator, to obtain one number representing the premise of each rule, (d)Shaping of the consequence of the rule by implication, and (e) Defuzzification

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MSc Thesis:

Similarly, the Fuzzy logic will be used in this study for the Cua Dat reservoir

‘operation, And this is the initial research using the Fuzzy Logic in operating reservoir

in Vietnam

L3 Overview of hydraulic and hydrological modeling

Any scientific field always need a developed process including monitoring data,recording and measuring dat simulation and explanation of natural phenomenon.Hydrology is a science of water on the earth To understand the hydrological eventscan be described in laboratory by physical models, Based on theory and practice,people have explained clearly the most of hydrological phenomenon such as rainfall,infiltration, evaporation, and simulated them by hydrological models (hydraulic andhydrological models)

Accordingly, hydraulic and hydrological models are tools to address the realhydrological cycle in a simplified way That kind of models are used for understandingthe hydrological processes as well as making hydrological prediction if there are somewater resources management and utilization activities are implemented (Tuan 2012)

‘The models are applied several algorithms to provide a quantitative relation between

the input data (eg rainfall, meteorological data) and output (eg runoff) The

mathematical models have been developed from 19th century with the simplestrainfall-run off model by Mulvaney (1851) to more sophisticated models such as MIKEPackage developed by Danish Hydraulic Institute; Soil and Water Assessment Tools(SWAT), HEC model developed by Hydraulic Engineering Center- USA; SIMONA2DISD hydrodynamic models by the Dept of Public Works and Delft 2D/3D byWLIDELFT HYDRAULICS Those models are used for simulation of flow, waterquality and sediment transport in estuaries, rivers, inigation system, channels andothers bodies They are fundamental to integrated water management as used forplanning and decision making (Tuan 2012)

‘The figure below shows the relationship between the various representations of

‘a model (Van Waveren et al 1999),

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MSc Thesis:

‘The conceptual model is developed on the

eset basis of knowledge of the system and

i serves as the basis for a mathematical

¬ cn fb model This model may be solved either

T analytically or numerically The model

—`— reated is further refined into a model

rorresenistens] |#⁄z program and finally into a Computer

i 1 Model by entering the proper input data

“em sen (Van Waveren etl 1999)

jure 2-1: Relationship between the

various representations of a model

Hydrological models have been used frequently in water resources planning and.management such as hydrological forecasting, reservoir operation, water quality,research on flood, inundation and drought, designing irrigation system, supporting forthe integrated water resources management ete, Appropriate model selection areessential for each research or project These selections should based on studyobjectives, considering input data and output data, expected results and solu

tive tool to solve

‘There are many studies on water field that using model as an eff

problems According to Piman et al (2012), the authors used HEC and SWAT models

to simulate and evaluate flow changes from hydropower development and operation in

še San and Sepork of the Mekong basin Long etal (2007) used MIKE

11 simulation model to set up control strategies for Hoa Binh reservoir operation, Theyrivers: SeKong,

concluded that this model is an effective tool for optimizing complex system.Bahremand and Smedt (2007) used distributed hydrological modeling (WETSPA) andsensitivity analysis in Torysa Watershed, Slovakia to predict daily discharge value

‘They also presented that a strategy by incorporating a model-independent parameterestimator PEST for automatic calibration and sem ivity analysis,

In this study, MIKE 11 model will be selected to rout the flow, which is released,from the Cua Dat Reservoir operation to the downstream area in order to evaluate ortest discharge value within constraint system at control points MIKE 11 model is a

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‘The study area has slope topography, short length of river and combine complexrain regime to make flood regime change complicatedly In this study, the authorselects the MIKE 11 model for routing the flow on the Ma-Chu river network To applythis model for study area, the understanding of model theory plays an important role.

‘The briefly description of the model theory according to DHI user's manual asfollowing (Kmen! 2008)

The most commonly applied Hydro-Dynamie (HD) model is a floodmanagement tool simulating the unsteady flows in branched and looped river networksand quasi two-dimensional flows in floodplains When using a fully dynamic wavedescription, MIKE 11 HD module solves the equations of conservation of continuityand momentum (the “Saint Venant’ equations) as bellow’

ec: momentum distribution coefficient

‘The MIKE 11 solution of the continuity and momentum equations is based on

an implicit finite difference scheme developed by Abbott and Ionescu (1967) Thescheme is setup to address any form of the Saint Venant equations — such askinematic, diffusive, or dynamic The water level and flow are calculated at each time

step, by solving the continuity equation and the momentum equation using a 6-point

‘Abbot scheme with the mass equation centered on h-points and the momentum

equation centered on Q-points By default, the equations are solved with 2 iterations.

‘The first iteration starts from the results of the previous time step and the second usesthe centered values from the first iteration The number of iterations is user specified(DHI 2011)

Cross sections are specified in both area and longitudinal location through the

user interface, The water level (h points) is calculated at each cross section and at

model interpolated interior points located evenly and specified by the user-enteredmaximum distance The flow (Q) is then calculated at points \dway betweenneighboring h-points and at structures (DHI 2011)

‘The hydraulic resistance is based on the friction slope from the empiricalequation, Manning's or Chezy, with several ways of modifying the roughness toaccount for variations throughout the cross-sectional area (DHI 2011)

Trình Xuan Manh

MSc Thesis:

CHAPTERHI THE STUDY AREA

IIL Description of the study area

IILL.1 Location of the study area

‘The Ma River basin is located in the northwest region of Vietnam, on theeastern slope of the Truong Son mountain range bordering Laos on the West Theupstream basin is located in Vietnam, the middle basin is located in Laos and thedownstream is located in Vietnam Accordingly, the Ma River basin is an international

basin and is the 4" in biggest river basins in Vietnam following The MeKong, Dong Nai and Red river basin The whole river spreads from 22°37°30""N to 20°37°30""N and 103°0S"10E to 106"05°10"E (IWRP 2003),

~The North borders on Da river basin, Boi river and Vac river basin;

= ‘The West borders on the Mekong river basin;

~The South borders on Hieu and Muc river basin;

~The East borders on the East Sea.

Figure 3-1: Location of study in the Thanh Hoa province in Vietnam

Trình Xuan Manl:

MSc Thesis:

“The total catchment area is about 28,490 Km, of which area in Vietnam is 17,600 Km? accounting for 62% of whole area and area in Laos is 10,800 Km*

corresponding to 38% (IWRP 2003) The major tributaries of the Ma river systemoriginates from the high mountains of Tuan Giao district which belongs to Lai Chauprovince, Vietnam The highest point of the upstream partis 1,500 m, the river flowsthrough the arca of provinces and nation, namely, Son La, Lai Chau, Hoa Binh, Laosand Thanh Hoa, and flows into the East Sea finally via three river mouths, namely Hoi,Lach Truong and Lach Sung Accordingly, Hoi river mouth is a main mouth of the MaRiver The Ma River has length of 512 Km of which 102 km is located in Laos and inViet Nam is about 410 Km,

‘Table 3-1: Distribution of natural areas according to provincial border

of the Ma river basin (ha)

Possible

1 | Laos 1098251 |32.962 824063 — JHigh mountain

I [VieNam 1750249 [287.828 — [1299987

1 |DinBien 209475 Ï1969 188452 — ÏHighmoumain

2 |SonLa 477.038 | 29.981 394.115 |High mountain3— |HoaBinh 177836 |38734 83527 High land

4 | Nghe An 62.810 | 5.000 45,000 |High land

S| Thanh Hoa 823.090 | 194.464 | 588.803 [High land- Delta

‘Thanh Hoa province at Muong Lat, Quan Hoa location to discharge the East Sea at Hoi

estuary The basin has river density of 0.66 km/km?, the meandering index is 1,7, the

shape index is 0,17, the average slope of the basin is 17,6 % (IWRP 2003)

‘The Chu River basin is one of main tributaries of the Ma River in this riverbasin It is located in the downstream area The catchment of Chu River is about 7,500

of which 65% are located in Laos and 95% of Chu river catchment area is in

Trình Xuan Manh

MSc Thesis:

mountains (TWRP 200) The Chu River joins the Ma River at Giang confluence which

is about at 26 km away from Ma river mouth, The river originates from Sam Nua highmountain which belongs to Laos, with elevation of 2,000 m, this river flowsmeanderingly in dangerous high mountains such as Phu Nam (2.050 m), Phu Bo (1.455m), entering into Viet Nam at Nghe An province The main flow has a length of 325

Km of which 100 Km is located in Vietnam,

In Vietnam’s region, the Chu River flows on narrow and slope valleys with a lot

of waterfalls, There are 15 waterfalls from Muong Hình to Cua Dat location From theconiluence of the Dat River to downstream, the river networks have risen significantly.the Chu River has a protected dyke system and many large tributaries such as the AmRiver, the Dat River and the Dang River Among these tributaries, the Am River is alargest one

‘The Buoi River is a second main tributary of the Ma River This river originatesfrom Chu Mountain which belongs to Hoa Binh Province The main river flowstowards North-South direction joining the Ma River at Vinh Khang position, The

length of this river is about 130 km, basin area is 1,790 km? and average slope is 1.22.

‘The upstream of the Buoi River includes three major stream, namely Cai, Bin andCong Hoa streams,

‘The Cau Chay River is originated from Den Mountain flowing towards

East-‘West direction though out delta of Ma River south and Chu River north, The total

length is about 87.5 km and basin area is 551 km

The table 3-2 shows detailed characteristics of river shape in the Ma-Chu riversystem as below:

Table 3 of river shape of some large tributaries

Song Pee [me [xe [me Umm [ew

wo | eran |, [aren [MH Jaeatn with lược |aeeng [mm [SP [uy

(%) im) Jkwtkan® |(So) _[(kua/kan’)| index lindex

Timmer [ren lsmlez [se |r [me am [se

2 [am [ns faa fers fou [ai fps cost [ose ly

+ sme [sẽ fie [mn [iss five fiee ae foat Ji

+ in spss fir [án fw ae 03 lam luan

la L0 [332 fran ais fine an mm ly

° heo {me [em [me fais sự foie đán lo

7 esss ss five Jars fi fan aaron foie [ie Tin an aos oe Lm áp [ase

> là aa 0 [ác no Yass] ne Tous lan lap lim

(Source: Final engineering report of The Cua Dat Reservoir in operation period 2014)

Trình Xuan Manh

MSc Thesis:

Figure 3-2: Ma ~ Chu River Network in Vietnam.

IIL.1.3 Topographical characteristics

‘The Ma river basin spreads widely many regions between Vietnam and Laos

‘This basin ranges from Truong Son Mountain range to Northern Bay, the topography isstrongly fragmented and changing complexly The main slope directly ranges fromWest-North to East-South The topographi al elevation varies from 1.0 m to 2000 m.which can be di ed into three main categories of topography, are described as below:

- High mountain terrain: ‘This area isin the upper part of the river basin: from Ba

‘Thuoe location to upstream of Ma River, and from Cua Dat location to upstream ofChu River The highest elevation of this topography is Phu Lan Mountain withelevation of 2,275 m The elevation changes towards North-South direction The area

of this topography is about 23,228 km” and it takes 80% in total The forestry trees are

Trình Xuan Manh

MSc Thesis:

primary on this one Agricultural land is around 75.968 ha and accounted for 3,26% ofnatural area, the current area for agriculture is $1,466 ha There are many river valleys,those are advanced to construct multi-purpose- reservoirs in order (0 supply water for

‘many objectives such as power generation, water supply, flood prevention and control

‘and water environment.

~ Highland terrain: This arca almost distributes inthe districts such as Thach Thanh,Cam Thuy, \goe Lac, Trieu Son, Tho Xuan in the Thanh Hoa province and Tan Lac,Lac Son, Yen Thuy in Hoa Binh province The elevation of this terrain varies from 20

m to 150 m, This region has a potential to develop industrial plants, special trees within

cultivated area of 85,100 ha, current cultivated area is 58,100 ha On this terrain there

are many streams, rivers which have potential to construct reservoirs in order to supply

"water for irigation, domestic supply, flood control and environmental improvement

~ Valley terrain: This terrain lies totally in the Thanh Hoa province, and it haselevation from + 1.0 - +20 m In this terrain, the deltas have been formed due to thedevelopment of river network such as Vinh Loe; South of Ma River ~ North of ChuRiver; South of Len River

4 Geological, land and vegetable characteristics

A- Geological and land characteristics

This river basin has some geological and soil characteristics as following:

‘The upstream of the Ma River, the Chu River and Buoi River are mainly sediment Sand and gravel concentrate along the rivers

Magma-~ The middle of the Ma river basin: material construction is abundant.

~ The downstream has been generated by Preterozoi Nam Co stratum and Paleozoi

formation developed strongly in Thanh Hoa province where Merozoi sediment is

major

~ The Ma River Basin has 40/60 types of soils and has formed into LIsoil groups:

‘Sandy soil; Salt soil; Acidic alum soil; Alluvial soil, Bog soil and Permafrost soil; Greysoil; Black soil; Red soil; Humus soil, Valley soil; Leachy soil

~ Thanh Hoa province has 8 types including: Sandy soil; Salt soil; Alluvial soil; Greybog soil, Black soil, Grey soil, Red soil and Leachy soil

~ Among 8 soil types in Thanh Hoa province, Alluvial soil is main soil in delta andimportant soil to form a sustainable agriculture in local region,

B- Vegetable cover characteristics

Vegetable surface on the basin is very abundant in types, categories and isformed by differentiation of climate, geography and human activities

Geography of the basin occupies an important role in forming the vegetable onthis basin: high mountain terrain always has types of vegetation such as wide leat

forestry and brushwood Highland terrain forms wide leaf forest, secondary

brushwood, bamboo Delta terrain is mainly industrial trees, rie, fruit-trees

Among categories of vegetation, type of secondary vegetation and plantation are.major, Natural vegetation still is existed, but little

111.2 Climate and hydrological condition

11.2.1 Climate condition

‘The Ma river basin spreads on two latitudes and longitudes Therefore, theclimate of region varies on space The region has the tropical -monsoon climate Thereare four seasons in year including spring, summer, autumn and winter Climate ofdifferent regions are spatial and temporal distribution ‘The upper area is located on

Trình Xuan Manh

MSc Thesis:

North-West pattern climate and Chu River is on Central North pattern climate, Theothers are located on interaction area between above climates (IWRP 2003)

a) Precipitation

Precipitation of the Ma river basin has been divided into three different regions

“The upper part of Ma River has rain regime of Northwest region, the wet season startscarly and finish early than middle region, The Chu River basin lies on Central Northrainy region, the wet season comes late in range of 15 ~ 20 days; finish late in range of

10 -15 days than Norther region,

‘The annual average rainfall of the region varies from 1100 to 1860 mm/year,

‘The region has two seasons of rain which are dry season and wet season, According tothe statistical data of many years, the wel season of the Ma River upstream frequentlybegins from May to November and the dry season is from December to April Therainy season of Chu river basin begins frequently at the end of November to thebeginning of December Total annual rainfall of two seasons is strongly disproportate

‘The total rainfall of wet season accounts 65 ~ 70% of total annual rainfall, the totalrainfall in dry season only accounts 30-35% of total annual rainfall

‘Table 3-3: Average annual rainfall for many years at some stations

of the Ma river basin

‘Maximum rainfall in| Minimum rainfall in

Stations Period | Xomm) year year

Ximm) | Year | Xtmm) | Year

Song Ma — 1964-2010 nis) 1siz2 | d3 | 906 | 19A

‘Maximum rainfall in] Minimum rainfall in

Period | Xo (mm) year year

-lLaeh Truong 1960:2010 1625 | 2442 197 9A0 | 1976

HauLoc — 1961-2010 1609 | 2570 1963 607 | 1960NgaSon — 1960-2010 149 | 2403 197A 90 | 19

(Source: Final engineering report of Cua Dat Reservoir in operation period 2014)

Table 3-4: Annual rainfall characteristies

No | Stations | Aver | Max | Year | Min | Year | MavAia

No | Stations | Aver | Max | Year | Min | Year | Max/Min

10 cam Thuy | 1668 | 2678 | 1963 | 1014 | i977 26

ĐI Mai Chaw 2876 | 193 | 1120 | 198 26

(Source: Final engineering report ofthe Cua Dat Reservoir in operation period 2014)

b) Wind

Winter has North ~ monsoon wind due to strong Northern circulation,average wind speed is 2-3 m/s The North-East monsoon wind commonly begins fromDecember to February of next year In summer the common wind direction is South-East wind due to the Northern Air Circulation and the low position of Gulf of Tonkin,

it brings much more moisture to make heavy rain, The average wind speed is from 2 ~

2.5 mis This wind occurs from March to October with annual year Besides that, there

is dry and hot South- West wind in April and May It only occurs 3-4 times in yearwith 4 -5 days for one

Table 3-5: Monthly and annual wind speed at some stations

of the Ma river basin (m/s)

stations | 1) 2 |3 |4 | s |6 |7 8 | 9 | 10) m | a2 Rvel[Tuma Giao | 0708 | 07| 04 | 07 |07 [07/06 | 06 [a6 | 07] 07 |07long Mã | 1.6 | 20/16 | 13 | 10 |09 |08 | os|os [10/11 [14/12Hoi Xuân 1 15/15/16 L6 | L6 | L4 | L6 14| L3 |3 13|14|15tacSon L12 15] Lá | 16 14 |11|12 no lit |12 L1 |12|12

Ba Thuong | 1.3 L5 |13 |14 | 13 [12 |l3,12|13 L3 1312| L3[thanh Họa | L8 18 17 [19] 20/19 | 19 15] 17 |9 18,17) 18Nhủ Xuân | 14 14|13]14|18]|18|18/15Ì15lL6 lis [is [is

Trình Xuan Manl:

MSc Thesis:

Stations | 1 j2 |3 |4 | § |6 |7 18 | 9 |101H [12 AvelWenDinh L6 1# | 17 |17|16|13|15 12|13|15 talus [isHmhGi [1s [1.6 [16 [17 [20 [21 [21 17|19|22.22]19li9

(Source: Final engineering report of the Cua Dat Reservoir in operation peviod 2014)

©) Temperature

‘There are 02 regions on the Ma river basin with different temperature regime

‘The highland, cold season starts from November to February, dry season is from March

to October The temperature of this region is similar to North- West region The delta

of Ma river, average annual temperature is higher than the highland, The Winter endsearly than North region form 15 - 20 days, the highest temperature is higher than

highland, On whole basin, average annual temperature changes from 2274 to 23 6C.

Average sunshine hours are range from 1,756.7 tol.896.4 hrs/year

Table 3-6: erage monthly temperature for many years at some stations

tations — Ì 3 5 ? lô [it fiz aver

juan Giao [146] 163/195 |22.6 246) 251/252 [248/239 / 21.6] 183) 15.0] 21.0 ong Ma [16.1] 185 212|243 26.1 | 264 26.3 25.9) 25.1 22.8] 196) 163|224 Hoi Xuan | 16.6] 18.0/20.7 245) 269]27.6/27.6|270) 256) 285]205) 17.6) 230 LacSon —_|15.9]17.3|202|240/ 27.2] 280|28.3 [27.6] 26.3 28.7|204)17.3| 230 Bái Thuong [16.5 |17.5 20.1 |239/270]28.2 28.4] 27.6|26.6|24.3) 212/180] 23.3

‘water evaporation AZ = 230 ~ 250 mmiyear

‘Table 3-7: Monthly average evaporation of some stations of the Ma River Basintations |1| 2 |3 | 4 {5s [6 |7 |3 | 9 |t0|[ | 12 | aver

[Tuan Giao |579| 692 | 89.5 | 93.2 | 892 | 63.4 | 634 | 558 | 60.1 |597| 530 | 53.4 | 8068

Trình Xuan Manh

MSc Thesis:

tations [1] 2] 3) 4] 5] 6 ] 7] 8 | 9 fio] a] i [averlong Ma [65.0] 81.7 [111.6] 108.6] 101.4] 62.0 | 56.8 | 51.2 577 |60S| 576 | 576 | 872.0

Hoi Xuan _|[87.9|108.4] 141.3]133.0] 129.9] 904 | 78.8 [62.5 | 63.9 |ø80| 675 | 75.7 [1103.3]Lac Son |562| 63.5 | 898 |1022|1120| 892 | 862 | 62.8 | 588 [63.0] 558 | 562 | 895.7[Bai Thuong |308 42.5 | $3.0 | 65.3 | 79.2 | 648 | 644 | 520, 466 |J4&1| 411 | 426 | 6894

[Thanh Hoa [48.3[ 447 | 497 | 65.5 | 912 7935 | 81.7 | 597 561 |607| 556 | 565 | 749.2Nhu Xuan |477| 42.7 445 | 56.6 | 824 |795 | 85.8 [674 | 663 [72.3] 705| 67.1 | 1834Wven Dinh |546| 39.8 | 39.7 | s0.0 | 897 | 94.4 [104.3] 74.7 | 63.9 [748] 69.9| 649 | 820.7

total while that of August has maximum flow with 20 ~ 30% in total On the Chu

River, flood season often occurs from July to October, accounts for 52 ~ 60% in total

‘The month that has maximum flow is September with 20 -24 % in total annual flow

Dry flow occurs in dry season in year The Ma River Basin has dry seasonwhich is from November to May Besides that dry season spreads 08 months, fromOctober to June on the Chu River Basin, Amount of flow in this season only takes 20 —35% in total, In general, dry season can be divided into 03 periods: First periodincludes 02 months (November and December), this period can be seen as middleperiod between 02 casons, maximum middle dry period is from January to April in

year

THL3 Population and economic characteristics

11.3.1 Population of the study area

According to the statistical yearbook 2012, the population of the Thanh Hoa

province is about 3,697,227 people Highland population is 718,000 people The others

Trình Xuan Manh

MSc Thesis:

‘Thanh, Meo who live in high mountain region The: is no border among life area ofthe peoples They live together forming a people community on this basin

I1L.3.2 Economic characteristics

Based on statistical data in year of 2007, general economic distribution of the

‘Thanh Hoa province was as follow: Industry was 36.87 %, Service was 3477 %,

ture, Forestry and Fishier was 28.36 % of GDP in year of 2007 was 25,689.3billion VND The economic growth rate was about 10.5 %

‘The Cua Dat reservoir has been constructed on Chu River and in Xuan My

‘Commune, Thuong Xuan District, Thanh Hoa province (Figure 3-4) Ths s the largestreservoir which has maximum storage on the Ma ~ Chu river system with total storage

of 1,364 million cubic meter Some main parameters of the Cua Dat Reservoir areshown in the table 3-8

-Main objectives of the reservoir:

‘This is a multi-purpose reservoir with following objectives:

= To contro flood in order to protect downstream area with probability flood of0.6 % To ensure water level ofthe Chu River at Xuan Khanh station (Tho Xuandistrict) is lower than 13.71 meter;

~ Supplying domestic and industrial water with suitable discharge of 7.715 mỬs;

= Imigading for 86,862 ha of cultivated land (Including Nam Song Chu region is

54,301 ha and Bae Song Chu ~ Nam Song Ma is 32,831 ha)

~ Generating hydropower with installed capacity of 97 MW

Trình Xuan Manh

MSc Thesis:

~ Supplying additional water in dry season with discharge of 30.42 mÏ/s in order

4o control salt intrusion at Ham Rong Bridge (lower than 1 %e)

‘Table 3-8: Some main parameters ofthe Cua Dat Reservoir

No [Parameters Units [Values

T | Basin parameters

1 Basin area Flv km’ 5938

2 ‘Annual average discharge Qo [mis 115

Design maximum discharge P = 0 ,1% mis 15,400

4 ‘Test maximum discharge P = 0,01% mis 22,100

T1 | Reservoir parameters

1 | Surface area ofthe reservoir at useful water evel km? — |3079

2 [ Normal water level m 110

3 Dead water level Tm Tả

4 Total storage Wth Tiotm [1364

5 ‘Conservation storage Whi 10m |79370

6 Flood control storage Wy 10'm |36860 7 | Dead storage We lỨm" |26869

HH | Construction

Dam

1 Dam crest elevation Tm 122.50

2 Maximum height of the dam [m 115.50

Valve

1 _|Susface weir withare vale

2 | Weirerest elevation " 7

3— [No.of weir bays 05

4 Quantity and size of valves n®xI) 5(11x17)

5 Maximum release /mw 11.594.

Hydropower Plant [

1 [Install capacity MW [97

2 ‘Maximum turbin discharge mis 156.26

3 Minimum turbin discharge mis 38.29 +] IƯkNh

Trinh Xuan Manh

MSc Thesis:

No _ | Parameters Units | Values

5 No of turbines Groups | 02

(Source: Final engineering report of The Cua Dai Reservoir in operation period 2014)

i

7)

The East Sea

Figure 3-4: The location of the Cua Dat Reservoir on the Ma-Chu river system

~ Existing operation rule curve of the Cua Dat Reservoir:

Reservoir operation plays an important role and is one of problems related to

‘water resources planning and management Generally, after dam construction, an

‘operation policy has been established to help managers giving significant decisions.Operation policy is determined based on water storage, water demand and all ofinformation of inflow with current reservoir status ‘The single purpose reservoirdecides an operation policy which aimed to maximize that purpose interest The multipurpose reservoir is optimal release allocation in order to balance interest amongpurposes Finally, the complex operation is based on amount of objectives andmembership functions

‘The Cua Dat Reservoir has been operated since 2012 Annual operation policy

of this reservoir is established by Ministry of Agriculture and Rural Development

(MARD) According to new operation policy during the flood season in 2013 to the

‘beginning of flood season in 2014, included 7 main chapters with Following concepts(1) General article; (2) Regulated operation in flood season in 2013; (3) Regulated

Trình Xuan Manh

MSc Thesis:

operation in dry season in 2014; (4) Emergency operation; (5) Monitoring

‘Meteorological ~ hydrological data; (6) Responsibility and Right; (7) Implementationpolicy According to the purpose of this thesis, the third policy is considered to be themost important The articles of third policy will be briefly described as below:

Article 9: Before the dry season in 2014, Song Chu Irrigation Company bas to plan tosupply water which is based on current storage reservoir, meteo-hydrological forecast,

‘water demand It should be reported to the Department of Agriculture and RuralDevelopment of Thanh Hoa province, and all of water users inthe system

Article 10: Regulate water level of reservoir in dry season

1~ During regulated operation, the reservoir elevation must be above or equal thelower rule curve in operation policy

2+ Lowest reservoir elevation at the end of every month is described as below:TIME ï3UXH ï3UI T2WH 31M T3UNV T3UV | 30NTLWE

» |? 95 90 81 1 4 B

(m)

Article 11: When the reservoir elevation is above or equal the lowest rule curve, SongChu Irrigation Company must supply enough water to all of water users according tothe water supply planning,

Article 12: Hydropower generation schedule of the Cua Dat and Doc Cay hydropowerplant have to follow the irrigation schedule of the Cua Dat reservoir

Article 13: Operate water supply in some emergency cases

1- When the reservoir elevation is lower than lower rule curve and above inactivelevel, Song Chu Irrigation Company and water users need to implement water

saving solutions,

2+ When the reservoir elevation is equal or lower than inactive level, Song ChuIrrigation Company need to plan a water supply schedule using inactive storage,then, reports the Department of Agriculture and Rural Development, Thanh Hoaprovince in order to make decision and implement

‘Some figures that the author collected alter the field survey to the Cua DatReservoir in 2014 Those pictures present clearly constructions or parameters related tothe Cua Dat Reservoir such as dam, flood valve, spillway, storage, intake tower, andweir Those pictures are as below:

Trình Xuan Manh

MSc Thesis:

IV.1, Data collection

In this thes

CHAPTER IV DATA AND METHODOLOGY

„ the author used some kinds of data for the contents such as:

Determining water demand, Optimizing reservoir operation and Numerical model Thedatasets were used in this study including meteorological data, hydrological data, the

‘Cua Dat Reservoir data and some other information regarding to crops, population andindustrial zones They are listed in the following table:

Table 4-1: Kinds of data were used in the studyCategories Data Sources

Climate

Hydrology

RainfallEvaporationRelative humidityWind speedSunshine hours

‘Water level of riversDischarge of rivers

National center for Meteorological Service

National center for Meteorological Service

Song Chu IrrigationCompany

as checking, approved by these organizers, Hence it is able to have confidence intothose sources The data collection plays an important role in the thesis calculation, as a

foundation is to determine water demand of each crop, operate the reservoir and set the

hydraulic model for study area and achieve the better output of this thesis so far:

Trình Xuan Manh

MSc Thesis:

IV.L.1 Meteorological data

In the study area, there are many rainfall stations and meteorological stations

‘These stations have been located in or close to the basin and have a long time period of

‘observation (from 1980 to 2009) However, the author did not use all of them, it onlyused some of them due to data quality and location of stations

In order to define the water demand of each crop and cultivated plants, theauthor used the meteorological data of the Thanh Hoa station such as rainfall,evaporation, relative humidity, wind speed and sunshine hours within time interval ofdaily period of 02 years (2011 and 2012) Some of figures of these data are shown asfollowing:

According to the Figure 4-1, we can see that maximum rainfall occurs in themonth of September in year of 2011 and 2012 The rainfall in the month of January toMay is quite small, The rainfall inereased significantly from June to September and itreaches a peak at September with more than 700 mm in year of 2011, more than 400 in

‘year of 2012, Then, it decreased from October to April

Monthly rainfall at Thanh Hoa station in year of 201182012