MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT WATER RESOURCES UNIVERSITY ************** OPTIMAL RESERVOIR OPERATION FOR WATER SUPPLY IN DRY SEASON: THE CASE STUDY OF CUA DAT RESERVOIR IN THE MA-CHU RIVER BASIN TRINH XUAN MANH MSc Thesis September 2014 Optimal reservoir operation for water supply in dry season: the case study of Cua Dat reservoir in the Ma – Chu river basin Master of science thesis By Trinh Xuan Manh Supervisor Dr. Nguyen Mai Dang (WRU) Mentors HA NOI September 2014 This research is finished for the partial fulfillment of requirements for the Master of science degree at Water Resources University, Ha Noi, Viet Nam i Abstract Water supply of reservoirs and especially reservoirs used for irrigation, hydropower, aquaculture, navigation, environment…in the dry season are often troubled due to increasing water demands according to the economic development and society, while the flow to the reservoir is limited. In recent years, the depletion of the river flow during the dry season occurs more frequently and at a more intense level. This is partly due to forest coverage reduction in the upstream of river basins, and partly due to the effects of climate change.
Hence, computation of the optimum water supply of reservoir for the water demands in the dry season is needed. This study presents the initial research on applying Fuzzy Logic Algorithm for optimal operation of water supply in the dry season of 2011-2012 of the Cua Dat Reservoir in the Chu River basin, Thanh Hoa province. The Cua Dat Reservoir is a multi-purpose reservoir for the following tasks: flood prevention, water supply, irrigation, power generation, and environmental flows. In addition, MIKE 11 model is also used to simulate the release from the reservoir to the 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 is developed for the Fuzzy operating systems for the Cua Dat Reservoir and is meant to determine the optimal discharge process in case of shortage of water in the dry season. Inflows, releases and water levels of the Cua Dat Reservoir were collected from actual operation of the reservoir. For water demand of stakeholders, the author determined that the total water demand for whole area was about 4547 Mi.
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 water demand more than actual release throughout the dry season of 2011-2012. The initial research has been successful 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 demand, Fuzzy rule, MIKE 11 model.
Trinh Xuan Manh MSc Thesis ii Acknowledgement First of all, I would like to give a big thank to all people who have supported and assisted me during the Master Thesis Research. Thanks for their support, encouragement and guidance that allowed me to complete this study in time. Especially, I would like to express my appreciation to Dr. Nguyen Mai Dang, my supervisor, for his unlimited encouragement, guidance, comments and technical supports on the Fuzzy Logic approach and other models as well as the thesis writing process from the beginning of the thesis research.
I would like to thank NICHE-VNM-106 project from the Government of the Netherlands for their financial support during the MSc study in the ThuyLoi University. I thank to Mrs. Hoang Nguyet Minh and Mrs. Vu Thi Thuy Ngan who made a linkage between me and NICHE.
I also would like to thank Assoc. Nguyen Thu Hien, Dean of the Faculty of Water Resources Engineering, for her help and comments during the Master study in the ThuyLoi University. I wish to thank Dr. Ilyas Masih and Ms.
Martine Rutten for their feedback, references and support from the proposal process. I also wish to thank Mrs. Mariette Van Tilburg, my English teacher, for her comments and support from the final thesis report. I 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 Resources and Environment in Vietnam for your assistance in the last two years. You will always be in my mind. Last but not least, I want to take this opportunity to show my appreciation to my family, my close friends for their inspiration and support throughout my life; this research is simply impossible without you. Trinh Xuan Manh MSc Thesis iii Table of Contents CHAPTER I: INTRODUCTION.
Objectives and Research questions. Objectives of the study. Structure of the thesis .3 CHAPTER II: LITERATURE REVIEW. Studies on reservoir operation using optimal theory.
Fuzzy logic theory. Overview of hydraulic and hydrological modeling .11 CHAPTER III: THE STUDY AREA. Description of the study area. Location of the study area.
Geological, land and vegetable characteristics. Climate and hydrological condition. Population and economic characteristics. Population of the study area.
Description of the Cua Dat Reservoir .24 CHAPTER IV: DATA AND METHODOLOGY. Cua Dat reservoir operation data. Determining total water demand. Optimal analysis and Fuzzy logic approach for Reservoir operation.
Methods using in optimal reservoir operation. Objective functions and constraints.3 Using Fuzzy logic technique to optimize the Cua Dat reservoir operation54 IV. Hydraulic and hydrological model setup. Determination of the model inputs.
Model calibration and validation. 65 Trinh Xuan Manh MSc Thesis iv CHAPTER V: RESULTS AND DISCUSSIONS. Optimizing the Cua Dat reservoir operation. Routing the release to the downstream .74 CHAPTER VI: CONCLUSIONS AND RECOMMENDATIONS .i Trinh Xuan Manh MSc Thesis v List of Figures Figure 2-1: Relationship between the various representations of a model.10 Figure 3-1: Location of study in the Thanh Hoa province in Viet Nam .13 Figure 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 .26 Figure 3-5: The main dam of the Cua Dat Reservoir .28 Figure 3-6: The spillway of the Cua Dat Reservoir .28 Figure 3-7: The storage of the Cua Dat Reservoir .28 Figure 3-8: The intake tower 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 .30 Figure 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 .31 Figure 4-4: Distribution of relative humidity at Thanh Hoa station in 2011 & 2012 .32 Figure 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 .35 Figure 4-9: Seasonal period and chart of water requirement of Spring paddy in 2011 39 Figure 4-10: Seasonal period and chart of water requirement of winter paddy in 2011 .41 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 .48 Figure 4-13: General flow chart of optimal reservoir operation in dry season .52 Figure 4-14: Fuzzy inference system for Fuzzy Mamdani .56 Figure 4-15: Transformation of input variable to membership value .57 Figure 4-16: Membership function for reservoir level for Fuzzy Mamdani model .58 Figure 4-17: Membership function for inflow for Fuzzy Mamdani model .58 Figure 4-18: Membership function for water demand for Fuzzy Mamdani model.59 Figure 4-19: Membership function for release for Fuzzy Mamdani model .59 Figure 4-20: Fuzzy rules base for operation of Cua Dat reservoir .60 Trinh Xuan Manh MSc Thesis vi Figure 4-21: Process of application, implication and aggregation .61 Figure 4-22: Hydraulic network of the Ma – Chu river basin .65 Figure 4-23: Observed and simulated hydrograph at Cua Dat station in 2006 .67 Figure 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 Nhan Station in 2006 .69 Figure 4-26: Observed and simulated hydrograph of water level at Xuan Khanh Station in 2006 .69 Figure 4-27: Observed and simulated hydrograph of water level at Giang Station in 2006 .70 Figure 4-28: Observed and simulated hydrograph of water level at Ly Nhan Station in 2008 .71 Figure 4-29: Observed and simulated hydrograph of water level at Xuan Khanh Station in 2006 .71 Figure 4-30: Observed and simulated hydrograph of water level at Giang Station in 2006 .72 Figure 4-31: Structure of fuzzy system for Cua Dat reservoir .73 Figure 4-32: Comparison of water demand and fuzzy and actual releases .74 Figure 5-1: Hydrograph of optimal operation at the Bai Thuong weir .75 Figure 5-2: Hydrograph of optimal operation at the Xuan Khanh station .75 Figure 5-3: Hydrograph of optimal operation at the Giang station .76 Trinh Xuan Manh MSc Thesis vii List of Tables Table 3-1: Distribution of natural areas according to provincial border of the Ma river basin (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 (m/s) .21 Table 3-6: Average monthly temperature for many years at some stations .22 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 requirement of winter paddy in 2011 .41 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 reservoir downstream 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 .64 Table 4-14: Results of MIKE 11HD model calibration at Ma-Chu river basin in 2006 .70 Table 4-15: Results of MIKE 11HD model validation at the Ma-Chu river basin in 2008 .72 Table 4-16: The NASH for calculation of alternatives .74 Table 5-1: Flow characteristics at the Chu River downstream using optimal operation .76 Trinh Xuan Manh MSc Thesis 1 CHAPTER I INTRODUCTION I.
Background Reservoirs play an important role in the development of many countries.