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Irrigation Systems - Book |
Book Information
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Irrigation Systems
Design, Planning and Construction Adrian Laycock ISBN: 978 1 84593 263 3
Price: £65.00 / US$130.00 / €105.00
Subject Classification: KNAC, TVDR Territorial Market Rights: World
Publisher:
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Of all the confrontations man has engineered with nature, irrigation systems have had the most widespread and far-reaching impact on the natural environment. Over a quarter of a billion hectares of the planet are irrigated and entire countries depend on irrigation for their survival and existence. Considering the importance of irrigation schemes, it is unfortunate that until recently the technology and principles of design applied to their construction has hardly changed in 4,000 years. Modern thinking on irrigation engineering has benefited from a cross-fertilization of ideas from many other fields including social sciences, control theory, political economics and agriculture. However, these influences have been largely ignored by irrigation engineers.
Drawing on almost 40 years of experience of irrigation in the developing world, Laycock introduces new ideas on the design of irrigation systems and combines important issues from the disciplines of social conflict, management, and political thinking.
Audience:
Designed to appeal to all those involved in planning, managing and operating irrigation systems, this book will interest engineers, technicians, agriculturalists, economists, students and policy makers.
Contents:
- Evolution and a Prelude to Change
- Elements of Irrigation
- Water Management
- Canal Operation and Automation
- Irrigation Water Demands
- Canal Architecture
- Canal Control Structures
- Low-Pressure Pipelines
- Canal Lining
- Canal Hydraulic Design
- Troubleshooting – Feedback from the Field
- Costs and Economics
Table of Contents
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CHAPTER 1 |
EVOLUTION AND A PRELUDE TO CHANGE |
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1.1 |
A World of Canals |
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1.2 |
The Importance of Small Canals |
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1.3 |
All- purpose Canals |
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1.4 |
Pipelines- why and when |
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1.5 |
Evolution of Irrigation Systems |
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1.6 |
Aid, Finance and Politics |
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Historical |
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Colonial |
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Post-colonial |
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Socialist economic decree |
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The European Union |
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Oil wealth |
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Developed countries |
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Private development and self-help |
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Commercial schemes |
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Virtual water and self-sufficiency |
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1.7 |
We have an Attitude Problem |
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1.8 |
Prelude to Change |
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References and further reading for chapter 1 |
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PART 1 - PLANNING |
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CHAPTER 2 |
ELEMENTS OF IRRIGATION |
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2.1 |
What can irrigation do? |
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2.2 |
Productive, Partial and Protective Irrigation |
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The Upper Swat Canal, evolution from protective to productive |
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Deficit irrigation – the strange case of Albania |
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2.3 |
Equity and Equality |
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2.4 |
Sustainability |
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2.5 |
Guaranteed Flow |
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2.6 |
The Downside – tragic environmental side effects |
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References and further reading for chapter 2 |
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CHAPTER 3 |
WATER MANAGEMENT |
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3.1 |
Levels of Water Management |
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Level 0 - Bulk issues |
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Levels 1 and 2 - Main system |
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Level 3 - Distribution |
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Level 4 - Watercourses, blocks and farm groups |
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3.2 |
Delivery Scheduling |
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3.3 |
Uncontrolled continuous flow |
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Basin flooding of paddy rice |
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The Talli project - wild flooding |
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Controlled wild flooding on the Rufiji |
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The Gezira project flows continuously against the rules |
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Proportional flow |
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3.4 |
Supply scheduling |
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Rotation |
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Pivot points |
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Warabandi |
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Shejpali |
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Indenting |
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3.5 |
Flexibility |
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3.6 |
Demand Scheduling |
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Water on demand |
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Arranged scheduling |
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Semi-demand, arranged scheduling |
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Limited rate, arranged scheduling |
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3.7 |
Intermittent Flow |
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Response time |
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Filling time |
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Absorption |
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Health |
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3.8 |
Institutional Management |
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Line management |
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Unit management |
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Authority and assistance - conflicting roles of water managers |
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Farmer participation in management |
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Privatisation |
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3.9 |
Water Charges |
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By volume |
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By area |
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By crop |
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By time |
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By number of irrigations |
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By season |
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By manipulation of controlled prices |
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By forfeit of crop |
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Free water |
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Education |
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References and further reading for chapter 3 |
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CHAPTER 4 |
CANAL OPERATION & AUTOMATION |
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4.1 |
How Water Flows |
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4.2 |
Canal Sensitivity and Response Time |
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4.3 |
Modes of Control |
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Upstream control |
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Downstream control |
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Mixed control |
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Constant volume control |
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Centralised control |
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4.4 |
Intermediate Storage |
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Storage ponds |
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Night storage canals |
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Night storage vs. night irrigation |
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Level-top canals |
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Related level control |
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Operational spillage |
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Conjunctive use of groundwater |
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Low-pressure pipelines |
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4.5 |
Gate Operation |
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Manual gate operation |
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Powered or motorised gate operation |
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Gate self-operation |
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4.6 |
Gate Control |
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Manual control |
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Refusal gates |
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Remote control and configuration |
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SCADA |
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4.7 |
Why Automation |
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Automation to save labour |
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Automation for easier operation |
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Automation and control |
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Partial Automation |
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4.8 |
Passive Automation |
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Long-crested weirs |
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Self-regulating float-operated gates for constant water level |
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Hunting and transients |
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Counterweighted gates for upstream control |
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Proportional dividers |
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Flumed outlets for proportional discharge |
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Baffle distributors for constant discharge |
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4.9 |
Active Automation |
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Control theory |
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Fuzzy logic |
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Active automation of a canal system |
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Instrumentation, communication and motorisation |
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4.1 |
Evolution from Manual Protective to Automated Productive - a case study |
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References and further reading for chapter 4 |
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CHAPTER 5 |
IRRIGATION WATER DEMANDS |
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5.1 |
Estimating Irrigation Requirements |
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Why plants need water |
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Evapotranspiration |
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Crop water demand |
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Estimating rainfall |
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Field irrigation requirements |
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The root zone |
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Available water |
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Cropping patterns and intensity |
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Calculating field application rate |
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Stream size |
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5.2 |
Water losses |
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Seepage |
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Leakage |
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Management loss |
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Dead storage |
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Absorption loss |
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Evaporation |
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Deep percolation |
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Runoff |
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5.3 |
Irrigation Efficiencies |
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Conveyance efficiency |
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Management efficiency |
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Application efficiency (in-field) |
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Distribution efficiency |
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Overall efficiency |
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Other efficiencies |
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5.4 |
Canal and system duties |
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Canal duty |
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Water management affects canal duties |
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The demand envelope |
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Cropwise irrigation demand - the engineer’s approach |
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The unit stream - the farmer’s approach |
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Flexibility and congestion |
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References and further reading for chapter 5 |
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PART 2 - DESIGN |
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CHAPTER 6 |
CANAL ARCHITECTURE |
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6.1 |
Canal Layout and Water Delivery |
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Command |
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Head |
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Canal hierarchy |
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The tail-end, and associated problems |
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6.2 |
Planning a canal layout |
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Drainage lines |
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Ridge lines |
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Major and minor slopes |
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Blocking out |
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6.3 |
Canal Architecture |
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Parabolic |
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Trapezoidal |
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Filleted trapezoidal |
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Triangular |
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Rectangular |
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Circular or half-round |
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Other shapes |
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Compound channels |
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6.4 |
Canal lining philosophy |
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To line, or not to line? |
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Reasons for canal lining |
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Rapid response time |
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Pumping costs reduced |
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Land tenure problems reduced |
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More land available for cultivation |
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Integrity of cross-section maintained |
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Animal damage prevention |
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Crop encroachment prevention |
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Health |
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Ease of maintenance |
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Reduction of management losses |
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Prevention of seepage out |
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Prevention of seepage in |
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Reduction of siltation |
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Erosion prevention |
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Farmer damage reduced |
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Structures simplified |
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Discharge increased |
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Command level increased |
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Bank stability |
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6.5 |
Reasons for Not Lining |
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6.6 |
Strategies for Lining |
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Durability |
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Hydraulic performance |
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Water management systems |
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Construction requirements |
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Labour resources |
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Material resources |
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Maintenance |
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Levels of technology |
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Quality control and supervision |
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Reducing wastage |
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Reducing salinity |
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6.7 |
Canal Geometry |
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Slope |
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Best hydraulic section |
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Freeboard |
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Wind waves |
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Waves generated from gate operation |
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Waves caused by channel slope change |
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Bends |
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Bank width and slope |
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References and further reading for chapter 6 |
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CHAPTER 7 |
CANAL CONTROL STRUCTURES |
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7.1 |
Access and Safety |
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Canal inspection roads |
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Bridges |
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Access ramps |
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Escape steps |
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Limited side slopes |
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Trash racks |
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7.2 |
Health |
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7.3 |
Water Discharge Control |
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Head regulators - sluice gate type |
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Head regulators – moveable weir type |
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Turnouts - undershot gate type |
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Turnouts - overshot gate type |
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Turnouts - drop inlet type |
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Modular control gates |
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Constant discharge modules |
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7.4 |
Flow division |
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Proportional dividers – bifurcators & trifurcators |
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Open flumes and proportional modules |
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7.5 |
Water Level Control - Cross Regulators and Checks |
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Gated cross regulators for upstream control |
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Choice of gate |
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Self-regulating cross regulators for upstream control |
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Self-regulating cross regulators for downstream control |
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Fixed weirs as cross regulators |
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Notched falls |
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Check structures |
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7.6 |
Velocity control |
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Drop structures |
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Baffled chute drops |
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Overfall and chute drops |
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Pipe drops |
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Rough channels |
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Flow arresters |
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7.7 |
Turbulence Control |
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Stilling basins |
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Transitions and fluming |
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7.8 |