Conjunctive Use of Saline and Non-Saline Coastal Aquifers for Agriculture
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Conjunctive Use of Saline and Non-saline Coastal Aquifers for Agriculture Muktarun Islam DOCTOR OF PHILOSOPHY Institute of Water and Flood Management BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY 2012 Conjunctive Use of Saline and Non-saline Coastal Aquifers for Agriculture by Muktarun Islam In partial fulfillment of the requirement for the degree of DOCTOR OF PHILOSOPHY Institute of Water and Flood Management BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY 2012 CANDIDATE’S DECLARATION It is hereby declared that this thesis or any part of it has not been submitted elsewhere for the award of any degree or diploma. …………………………… Muktarun Islam Dedicated to My parents and my daughter TABLE OF CONTENTS Title Page TABLE OF CONTENTS i LIST OF TABLES v LIST OF FIGURES vi LIST OF ABBREVIATIONS ix GLOSSARY x ACKOWLEDGEMENT xii ABSTRACT xiv CHAPTER 1: INTRODUCTION 1 1.1 Background 1 1.2 Objectives 3 1.3 Rationale 3 1.4 Limitations 4 CHAPTER 2: LITERATURE REVIEW 5 2.1 Introduction 5 2.2 Groundwater in Coastal Environment 5 2.3 Upconing in Saline Aquifers 8 2.4 Aquifers Salinity and Agriculture 14 2.5 Saline Aquifers Development 17 2.6 Conjunctive Use of Saline and Non-saline Waters 25 2.7 Conclusions 27 CHAPTER 3: PROBLEM STATEMENT 29 3.1 Introduction 29 3.2 State of Coastal Aquifers 29 3.3 Analysis of Saline Aquifers 33 3.3.1 Sharp interface 33 3.3.2 Density dependent flow 35 3.4 Saline Aquifers Development Constraints 35 3.4.1 Water quality constraints 36 3.4.2 Freshwater withdrawal constraints 37 3.5 Saline Aquifers Development 40 3.6 Conclusions 41 CHAPTER 4: MODEL DEVELOPMENT 42 4.1 Introduction 42 4.2 Multi-well Model 42 4.2.1 Physical description 42 4.2.2 Model development 43 4.3 Multi-strainer Model 45 4.3.1 Physical description 45 4.3.2 Model development 46 ii 4.4 Conclusions 52 CHAPTER 5: STUDY AREA 54 5.1 Introduction 54 5.2 Location, Extent, and Population 55 5.3 Physical Settings 59 5.3.1 Climate 59 5.3.2 Topography 60 5.3.3 Soil condition 60 5.4 Water Resources 61 5.4.1 Surface water 61 5.4.2 Groundwater 64 5.5 River Salinity 65 5.6 Aquifer Salinity 67 5.6.1 Sources of salinity 67 5.6.2 Extent of salinity 68 5.6.3 Impact of salinity 69 5.7 Agriculture 70 5.7.1 General 70 5.7.2 Land use 71 5.7.3 Cropping patterns 72 5.8 Conclusions 73 CHAPTER 6: AQUIFER GEO-HYDRAULIC POTENTIAL 75 6.1 Introduction 75 6.2 Geo-structural Connectivity 75 6.2.1 Regional stratification 75 6.2.2 Local stratification 78 6.3 Hydraulic Connectivity 80 6.3.1 Setting monitoring wells 80 6.3.2 Comparison of hydraulic heads 81 6.4 Aquifer River Interaction 83 6.4.1 Geo-structural interaction 83 6.4.2 Hydraulic interaction 86 6.5 Aquifer Hydraulic Head Variation 90 6.5.1 Local variation 90 6.5.2 Regional variation 92 6.5.3 Groundwater withdrawal 98 6.6 Conclusions 99 CHAPTER 7: AQUIFER SALINITY AND IRRIGATION SUITABILITY 100 7.1 Introduction 100 7.2 Saline and Non-saline Aquifer Domains Identification 100 7.2.1 Key informant interview 101 7.2.2 In-situ soil sample analysis 101 7.3 Salinity Quantification 104 iii 7.3.1 Setting salinity monitoring wells 105 7.3.2 In-situ water sample analysis 106 7.4 Irrigation Water Suitability 108 7.4.1 Irrigation water quality parameters 108 7.4.2 Irrigation water quality standard 109 7.5 Water Quality Evaluation 110 7.5.1 Water sampling for laboratory analysis 110 7.5.2 Evaluation of salinity 111 7.5.3 Evaluation of SAR 113 7.5.4 Evaluation of pH 114 7.6 Conclusions 115 CHAPTER 8: CONJUNCTIVE USE SCHEME FORMULATION 117 8.1 Introduction 117 8.2 Model Data Requirement 117 8.3 Model Data Generation 118 8.3.1 Setting multi-strainer monitoring wells 118 8.3.2 Mixing time in multi-strainer monitoring wells 119 8.3.3 Water sample collection and analysis 121 8.3.4 Generated model input data 122 8.4 Well Field Design Criteria Evaluation 125 8.5 Well Field Design Criteria Selection 128 8.6 Conjunctive Use Schemes Formulation 131 8.7 Saving Water with Conjunctive Use Schemes 140 8.7.1 Leaching requirement 141 8.7.2 Leaching requirement evaluation 141 8.8 Conclusions 142 CHAPTER 9: POTENTIAL USE OF DEVELOPED MODELS IN 144 SWAIWRPM PROJECT 9.1 Introduction 144 9.2 Description on SWAIWRPM Project 144 9.3 Water Use Problem Assessment Techniques 146 9.3.1 Questionnaire survey 146 9.3.2 Focus Group Discussion 147 9.3.3 Policy review 147 9.4 Lacking Water Availability 149 9.4.1 Farm structure and irrigation access 149 9.4.2 Timely availability of irrigation water 151 9.4.3 Problem with irrigation water quality 155 9.5 Policy Shortcomings 157 9.6 Irrigation Coverage 160 9.7 Conclusions 161 CHAPTER 10: CONCLUSIONS AND RECOMMENDATIONS 163 10.1 Conclusions 163 iv 10.2 Recommendations 166 REFERENCES 167 APPENDICES 183 Appendix- A 184 Appendix- B 185 Appendix- C 187 Appendix- D 189 Appendix- E 190 Appendix- F 191 Appendix- G 192 ACKNOWLEDGMENTS Firstly, I thank the Almighty Allah for giving me the strength and endurance to bring my Ph D research at its present stage. I wish to express my deepest gratitude to my supervisor Dr. M Mozzammel Hoque, Professor, IWFM, BUET for his invaluable guidance, continuous support, and high standard of mentoring that ha ve l ed m e t hrough t he w hole pe riod of m y P h. D w ork. Under hi s g uidance, I have successfully overcome many difficulties and learned to go forward in difficult situations. I a m very grateful t o hi m f or g reat e ffort h e put i nto to train me in the scientific research and to introduce m e with the “joys” of working i n t he f ield of water r esources development. I w ill always remember the first day of our meeting when he clarified me the definition of Ph. D and the least expectation from a P h. D research. I can sense now, finally I have just reached there. I am privileged and I feel proud of working with him. I express gr atefulness t o D r. M . S hah A lam K han, P rofessor, IWFM, BUET, D r. M ashfiqus Salehin, Professor, IWFM, BUET, Dr. M. Shahjahan Mondal, Professor, IWFM, BUET, Dr. A. K. M. Saiful Islam, Associate Professor, IWFM, BUET, and Dr. Md. Munsur Rahman, Professor & Director, I WFM, BUET for s erving on t he P h. D c ommittee a nd t he B oard of E xaminers. Their suggestions have been greatly helpful during the research and their critical review of the manuscript has greatly improved its clarity. I would like to make special mention to Dr. M. Shah Alam Khan for motivating discussions, most importantly on social research tool, Dr. Mashfiqus Salehin for e ditorial comments, Dr. M . S hahjahan M ondal for c ritiques on statistical analysis, and Dr. A. K. M. Saiful Islam for suggesting to include the models user’s guidelines. I thank Dr. Md. M otiur R ahman K han, e xternal m ember of t he B oard of E xaminers f or hi s va luable comments on the manuscript. I am grateful to all the other faculties of IWFM, BUET, in particular to Dr. Mohammed Abed Hossain for providing f acilities on water s ampling f or this work. I w ould l ike t o t hank D r. Hamidul Huq, Research Coordinator, Crossing Boundaries (CB) Project, IWFM, BUET for his co-operation to c onducting the s ocial r esearch in t he f ield a nd Md. S anaul K afi, R esearch Officer, CB P roject, IWFM, BUET for g iving time dur ing the f ield visit a nd installation of monitoring wells at the field research areas. I gratefully acknowledge the CB Project, IWFM and SaciWaters, Hyderabad, India for providing SAWA fellowship. This financial support has enabled me to do extensive research. I t ake this opportunity to sincerely acknowledge the Climate Change Trust Fund research project at IWFM, BUET for p roviding f inancial assistance i n t he f orm of R esearch Assistantship which has supported me to perform my work comfortably. I a lso e xpress m y t hanks t o a ll the s taff of IWFM, B UET f or t heir ki nd a ssistance a nd f or creating a ni ce and friendly atmosphere in my everyday l ife at the Institute. I acknowledge the continuous support of Md. Ismail, Library Assistant, IWFM, in using the Library facilities and for providing assistance in need. xiii I wish to extend my sincere gratefulness and appreciation to Engr. Md. Jamal Faruq, Assistant Engineer B ADC, Jessore Z one for hi s c onstant s upport, i nspiration, and he lp i n providing necessary data and giving me the absolute access to the laboratory and the technical assistance. I must a lso t hank his Laboratory s taff for t heir as sistance i n the an alysis of water qua lity parameters. I also like to thank all of my informants and respondents in field study areas for sparing valuable time and sincere effort to provide me with required field data.