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.
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.
CHAPTER 1 EVOLUTION AND A PRELUDE TO CHANGE
1.1 A World of Canals
1.2 The Importance of Small Canals
1.3 All- purpose Canals
1.4 Pipelines- why and when
1.5 Evolution of Irrigation Systems
1.6 Aid, Finance and Politics
Historical
Colonial
Post-colonial
Socialist economic decree
The European Union
Oil wealth
Developed countries
Private development and self-help
Commercial schemes
Virtual water and self-sufficiency
1.7 We have an Attitude Problem
1.8 Prelude to Change
References and further reading for chapter 1
PART 1 - PLANNING
CHAPTER 2 ELEMENTS OF IRRIGATION
2.1 What can irrigation do?
2.2 Productive, Partial and Protective Irrigation
The Upper Swat Canal, evolution from protective to productive
Deficit irrigation - the strange case of Albania
2.3 Equity and Equality
2.4 Sustainability
2.5 Guaranteed Flow
2.6 The Downside- tragic environmental side effects
References and further reading for chapter 2
CHAPTER 3 WATER MANAGEMENT
3.1 Levels of Water Management
Level 0 - Bulk issues
Levels 1 and 2 - Main system
Level 3 - Distribution
Level 4 - Watercourses, blocks and farm groups
3.2 Delivery Scheduling
3.3 Uncontrolled continuous flow
Basin flooding of paddy rice
The Talli project - wild flooding
Controlled wild flooding on the Rufiji
The Gezira project flows continuously against the rules
Proportional flow
3.4 Supply scheduling
Rotation
Pivot points
Warabandi
Shejpali
Indenting
3.5 Flexibility
3.6 Demand Scheduling
Water on demand
Arranged scheduling
Semi-demand, arranged scheduling
Limited rate, arranged scheduling
3.7 Intermittent Flow
Response time
Filling time
Absorption
Health
3.8 Institutional Management
Line management
Unit management
Authority and assistance - conflicting roles of water managers
Farmer participation in management
Privatisation
3.9 Water Charges
By volume
By area
By crop
By time
By number of irrigations
By season
By manipulation of controlled prices
By forfeit of crop
Free water
Education
References and further reading for chapter 3
CHAPTER 4 CANAL OPERATION & AUTOMATION
4.1 How Water Flows
4.2 Canal Sensitivity and Response Time
4.3 Modes of Control
Upstream control
Downstream control
Mixed control
Constant volume control
Centralised control
4.4 Intermediate Storage
Storage ponds
Night storage canals
Night storage vs. night irrigation
Level-top canals
Related level control
Operational spillage
Conjunctive use of groundwater
Low-pressure pipelines
4.5 Gate Operation
Manual gate operation
Powered or motorised gate operation
Gate self-operation
4.6 Gate Control
Manual control
Refusal gates
Remote control and configuration
SCADA
4.7 Why Automation
Automation to save labour
Automation for easier operation
Automation and control
Partial Automation
4.8 Passive Automation
Long-crested weirs
Self-regulating float-operated gates for constant water level
Hunting and transients
Counterweighted gates for upstream control
Proportional dividers
Flumed outlets for proportional discharge