Role of Sediment Transport in Operation and Maintenance of Supply and Demand Based Irrigation Canals: Application to Machai Maira Branch Canals UNESCO-IHE PhD Thesis

This work describes the role of sediment transport in the operation and maintenance of demand-based downstream controlled irrigation canals. Sediment deposition in these irrigation canals severely affects the operation of the automatic flow control system. The book also discusses sediment transport modelling in irrigation canals. A simplified 1-D mathematical model SETRIC (SEdiment TRansport in Irrigation Canals) has been improved with the inclusion of downstream control component for the downstream controlled irrigation canals. Based on field measurements and sediment transport modelling, a number of approaches have been proposed for sediment management in such irrigation canals by improvement in their design and operation. This book will be of interest to Irrigation Engineers and Managers, Hydraulic Engineers, Water Resources Engineers and Managers, Civil Engineers, and Agricultural Engineers.

1. INTRODUCTION AND BACKGROUND1.1 BACKGROUND1.2 RATIONALE OF THE STUDY1.3 SCOPE OF THE STUDY1.4 RESEARCH QUESTIONS1.5 RESEARCH HYPOTHESIS1.6 OBJECTIVES1.7 INTRODUCTION OF THE THESIS 2. INDUS BASIN IRRIGATION SYSTEM IN PAKISTAN2.1 GENERAL INFORMATION ABOUT PAKISTAN2.2 SOCIO-ECONOMIC SETTINGS OF THE COUNTRY2.3 WATER RESOURCES2.4 INDUS BASIN IRRIGATION SYSTEM2.5 HISTORY OF IRRIGATION IN THE INDUS BASIN 3. SEDIMENT TRANSPORT AND FLOW CONTROL IN IRRIGATION CANALS3.1. GENERAL INFORMATION ON SEDIMENT TRANSPORT AND MODELLING3.1.1 Incipient motion3.1.2 Bed load sediment transport3.1.3 Suspended sediment transport3.1.4 Total sediment load3.2. EVALUATION OF SEDIMENT TRANSPORT FORMULAE3.3. SEDIMENT TRANSPORT MODELLING3.4. SEDIMENT TRANSPORT MODELLING IN IRRIGATION CANALS3.5. SEDIMENT MANAGEMENT IN IRRIGATION CANALS3.5.1 Sediment control at intakes3.5.2 Sediment diverters (silt excluders)3.5.3 Sediment ejectors3.5.4 Settling basins3.5.5 Sediment control by canal design approach3.5.6 Operation and maintenance of silt affected irrigation canals3.6. FLOW CONTROL IN IRRIGATION CANALS3.6.1 Upstream control3.6.2 Proportional control3.6.3 Downstream control3.7. HYDRAULICS OF DOWNSTREAM CONTROL SYSTEM3.8. DESIGN CRITERIA3.9. FLOW CONTROL ALGORITHMS3.9.1. Supervisor Control and Data Acquisition System3.9.2. Proportional Integral Derivative (PID) control 4. SEDIMENTATION IN TARBELA RESERVOIR AND ITS EFFECTS ON PEHURE HIGH LEVEL CANAL4.1. SEDIMENTATION OF RESERVOIRS IN THE WORLD4.2. TARBELA DAM4.3. SEDIMENTATION IN TARBELA RESERVOIR4.3.1 Water availability at Tarbela Dam4.3.2 Sediment inflow to Tarbela Reservoir4.3.3 Tarbela Reservoir operation4.3.4 Sediment trapping in the reservoir and status of storage capacity4.3.5 Accumulated sediment deposition in Tarbela Reservoir4.4. DEVELOPMENT OF SEDIMENT DELTA IN A RESERVOIR4.4.1 Siltation process in reservoirs4.4.2 Formation of a delta4.4.3 Factors affecting sediment delta movement4.4.4 Reworking of the delta4.5. ANALYSIS OF THE SEDIMENT DELTA IN TARBELA RESERVOIR4.6. PROSPECTS OF SEDIMENT MANAGEMENT4.7. TARBELA DAM AND PEHURE HIGH LEVEL CANAL 5. HYDRODYNAMIC BEHAVIOUR OF MACHAI MAIRA AND PEHURE HIGH LEVEL CANALS5.1. BACKGROUND5.2. OBJECTIVES OF THE HYDRODYNAMIC MODELLING5.3. METHODS AND MATERIALS5.3.1. Irrigation infrastructure5.3.2. System operations5.3.3. Crop Based Irrigation Operations (CBIO)5.3.4. Discharge and water level controls5.3.5. Secondary offtakes operation5.3.6. Modelling canal operations5.3.7. Calibration of the model5.4. RESULTS AND DISCUSSION5.4.1. Model calibration and validation5.4.2. Steady state simulations5.4.3. Performance of Proportional Integral discharge controllers5.4.4. Effect of amount and location of discharge refusal on discharge control5.4.5. Testing of CBIO schedules5.4.6. Gate responses 6. SEDIMENT TRANSPORT IN MACHAI AND MAIRA BRANCH CANALS6.1. METHODOLOGY OF FIELD DATA COLLECTION6.1.1. Measurement methods6.1.2. Fieldwork arrangement6.2. IRRIGATION WATER SUPPLY TO USC-PHLC SYSTEM6.3. WATER DISTRIBUTION TO SECONDARY OFFTAKES6.4. SEDIMENT INFLOW TO THE SYSTEM6.5. RESULTS FROM MASS BALANCE STUDIES6.5.1. Mass balance in July 20076.5.2. Mass balance in December 20076.5.3. Mass balance in July 20086.6. OFFTAKES SEDIMENT WITHDRAWAL6.7. MORPHOLOGICAL CHANGES IN THE CANALS6.7.1. Cross-sectional survey in January 20076.7.2. Cross-sectional survey in July 20076.7.3. Cross-sectional survey in January 2008 7. CANAL OPERATION AND SEDIMENT TRANSPORT7.1. BACKGROUND7.2. SIMULATION OF IRRIGATION CANALS (SIC) MODEL7.2.1. Topography module7.2.2. Steady flow module7.2.3. Unsteady flow module7.2.4. Sediment module7.3. SEDIMENT TRANSPORT MODEL SET UP7.3.1. Sensitivity analysis7.3.2. Comparison between sediment transport predictors7.3.3. Model calibration and validation7.4. SCENARIO SIMULATION7.4.1. Simulations under existing conditions of water and sediment discharge7.4.2. Sediment transport under design discharges with existing sediment concentration7.4.3. Sediment transport under CBIO with existing sediment concentration7.5. SEDIMENT TRANSPORT IN PHLC7.5.1. Sediment transport capacity in PHLC7.5.2. Sediment transport capacity in the canals downstream of RD 2427.6. SCENARIO SIMULATIONS WITH TARBELA EFFECT7.6.1. Sediment transport at full supply discharge7.6.2. Sediment transport at existing discharge conditions7.6.3. Sediment transport under CBIO7.7. EFFECT OF FLOW CONTROL ON SEDIMENT TRANSPORT7.8. SEDIMENT CONCENTRATION ARRIVING AT RD 242 FROM THE PHLC7.9. COMBINED SEDIMENT CONCENTRATION AT CONFLUENCE FOR CBIO7.10. SEDIMENT TRANSPORT DOWNSTREAM OF RD 242 WITH COMBINED SEDIMENT INFLOW FROM MACHAI BRANCH CANAL AND PHLC7.10.1. At design discharge7.10.2. At existing discharge7.10.3. At Crop Based Irrigation Operations 8. DEVELOPMENT OF DOWNSTREAM CONTROL COMPONENT IN SETRIC MODEL8.1. BACKGROUND8.2. RATIONALE8.3. SETRIC MODEL8.3.1. Water flow calculations8.3.2. Roughness calculations8.3.3. Determination of roughness on the side walls8.3.4. Galappatti’s depth integrated model8.3.5. Separation of bed and suspended load8.3.6. Concentration downstream of inflow and outflow points8.3.7. Morphological changes in the bed8.3.8. Boundary conditions8.4. IMPROVEMENTS IN THE SETRIC MODEL8.4.1. AVIS and AVIO gates8.4.2. Gate index of AVIS/AVIO gates8.4.3. Hydraulics of AVIS/AVIO gates8.4.4. Discharge computation8.5. COMPUTATION PROCEDURE IN SETRIC MODEL FOR DOWNSTREAM CONTROL8.6. APPLICATION OF THE SETRIC MODEL TO AUTOMATICALLY DOWNSTREAM CONTROLLED IRRIGATION CANAL8.6.1. Calibration and validation of the model8.7. FLOW SIMULATIONS8.7.1. Flow simulation under design flow conditions8.7.2. Flow simulation at 50% of full supply discharge8.7.3. Flow simulation at 75% of full supply discharge8.8. SEDIMENT TRANSPORT SIMULATIONS8.8.1. Calibration and validation of SETRIC Model for sediment transport8.8.2. Sediment inflow to the irrigation canal under study8.8.3. Under design discharge with existing sediment inflow8.8.4. Under existing water and sediment inflow8.8.5. Under CBIO and existing sediment inflow 9. MANAGING SEDIMENT TRANSPORT9.1. TRADITIONAL APPROACH OF SEDIMENT MANAGEMENT IN INDUS BASIN IRRIGATION SYSTEM9.2. DESILTING OF IRRIGATION CANALS9.3. EFFECT OF SEDIMENT TRANSPORT ON UPSTREAM CONTROLLED IRRIGATION CANALS9.4. EFFECT OF SEDIMENT TRANSPORT ON THE HYDRAULIC PERFORMANCE OF DOWNSTREAM CONTROLLED IRRIGATION CANAL9.4.1. Effect of sediment deposition at the automatic flow releases9.4.2. Effect of secondary offtakes operation on sediment transport capacity9.5. EFFECT OF DIFFERENT OPERATION SCHEMES ON SEDIMENT TRANSPORT9.5.1. Effects of design discharge9.5.2. Effects of existing discharge9.5.3. Effect of different options of CBIO on sediment transport9.6. MANAGEMENT OPTIONS9.6.1. Operation under different discharge conditions9.6.2. Sediment transport under CBIO with increased sediment discharge from the Tarbela Reservoir9.6.3. Target water level and sediment transport9.6.4. Decrement setting and AVIS gates’ response9.6.5. Grouping and clustering of offtakes9.6.6. Offtakes close to cross regulators 10. EVALUATION10.1. SEDIMENTATION IN TARBELA RESERVOIR AND PHLC10.2. HYDRODYNAMIC BEHAVIOUR OF THE IRRIGATION CANALS10.3. FLOW AND SEDIMENT TRANSPORT IN THE IRRIGATION CANALS10.4. SEDIMENT TRANSPORT MODELLING10.5. DEVELOPMENT OF DOWNSTREAM CONTROL COMPONENT IN SETRIC MODEL10.6. MANAGING SEDIMENT TRANSPORT10.7. CONCLUSIONS AND WAY FORWARD REFERENCESLIST OF SYMBOLSACRONYMS APPENDICESA. SEDIMENT TRANSPORT RELATIONSHIPS UNDER EQUILIBRIUM CONDITIONSB. THE SAINT-VENANT EQUATIONS AND THEIR SOLUTIONC. ONE DIMENSIONAL CONVECTION DIFFUSION EQUATION AND ITS SOLUTION IN UNSTEADY STATE FLOW CONDITIONSD. MODIFIED EINSTEIN PROCEDURE FOR COMPUTATION OF TOTAL SEDIMENT LOAD FROM FIELD MEASUREMENTSE. CROP WATER REQUIREMENTS AND CROP BASED IRRIGATION OPERATIONSF. SEDIMENT INFLOW AT MACHAI BRANCH HEADWORKSG. SEDIMENT INFLOW AT RD 242H. RESULTS OF EQUILIBRIUM MEASUREMENTS SAMENVATTINGABOUT THE AUTHOR

Sarfraz Munir (Narowal, Pakistan, 1974), received his Bachelor and Master degrees in Agricultural Water Management from the North Western Frontier Province (now Khyber Pakhtunkhwa) Agricultural University, Peshawar, Pakistan in 1997 and 2000 respectively. He served from 1999 to 2009 in the International Water Management Institute (IWMI) in Pakistan. He has been engaged in a number of projects on performance assessment of irrigation systems in Pakistan, agricultural water management, environmental impact assessment of wastewater irrigation and the evaluation of modernized irrigation systems. His assignments included field measurements for agricultural and environmental water management like flow measurements in irrigation canals, hydraulic structures’ and downstream gauges’ calibration, longitudinal and cross-sectional surveys in irrigation canals, groundwater observations, installation of necessary equipment for surface water and groundwater observations, in situ water quality measurements, laboratory analysis of plant, soil and water quality, socio-economic surveys, hydraulic modelling, synthesis of field data and report writing. From 2006 untill 2011 he conducted his PhD study in Hydraulic Engineering-Land and Water Development Core, UNESCO-IHE, Institute for Water Education, Delft, the Netherlands.