Modern Land Drainage: Planning, Design and Management of Agricultural Drainage Systems, 2nd Edition

Cover
Half Title
Title Page
Copyright Page
Contents
List of tables
List of figures
List of boxes
Preface
About the authors
PART I Introduction
	1 Land drainage for agriculture
		1.1	Drainage objectives; Scope of the book
		1.2 Global drainage zones
			1.2.1	Temperate zone
			1.2.2	Arid and semi-arid zone
			1.2.3	Humid and semi-­humid zone
		1.3 Agro-hydrological
		1.4	Waterlogging control
			1.4.1	Positive and adverse impacts
			1.4.2	Responses to improved drainage
		1.5 Salinity control
		1.6	Drainage systems
		1.7 Bio-drainage
		1.8	Environmental impacts
			1.8.1	Stream flow regimes
			1.8.2	Water quality
			1.8.3	Wetlands and conservation drainage
			1.8.4	Public health
		1.9 Drainage development considerations
	2	Planning and design considerations
		2.1 Design rainfall
		2.2	Percolation of excess irrigation water
		2.3 Design of field drainage systems
		2.4	Determination of design criteria
	3 Remote sensing and field reconnaissance
		3.1	Need for drainage and problem diagnosis
		3.2 Remote sensing and aerial survey
		3.3	Field investigations
		3.4 Planning stakeholder engagement
		3.5	Stages of project preparation
		3.6 Operation, management and maintenance
	4	Assessment of costs
		4.1 Required information
		4.2	Discounting
		4.3 Evaluation indices
		4.4	Cost evaluation of open and pipe drainage systems incl. O&M
		4.5 Cost calculations for pipe drainage systems
			4.5.1	Cost structure for pipe drainage construction
			4.5.2	Guidelines for cost calculations
			4.5.3	Example cost calculation
PART II Investigations
	5	Climate, land, soil and environment
		5.1	Climate
			5.1.1	Climate; soil moisture balance calculations
			5.1.2 Climate: rainfall depth­duration­frequency studies
		5.2	Topography
		5.3	Soil and land conditions
		5.4	Soil parameters and properties
			5.4.1	Texture
			5.4.2	Plasticity index
			5.4.3	Bulk density and soil moisture content
			5.4.4	Sample quantity and density
			5.4.5	Data requirement for drain envelope design
		5.5	Watertable and groundwater
			5.5.1	Watertable observation wells
			5.5.2	Piezometric studies
			5.5.3	Groundwater sampling
		5.6	Hydrology and geohydrology
			5.6.1	Runoff and flooding
			5.6.2	Outlet conditions
			5.6.3	Geohydrological conditions
		5.7	Agriculture and irrigation
		5.8	Pilot areas and field testing
			5.8.1	Types of pilot areas
			5.8.2	Analysis of results of pilot areas
			5.8.3	Visual drainage need assessment
			5.8.4	Statistical analysis
		5.9	Environmental impact
			5.9.1	Environmental impact assessment
			5.9.2	Miscellaneous investigations
	6	Water in the soil
		6.1	Forms and nature of occurrence of water in the soil
		6.2	Pressures in the soil water
		6.3	Soil moisture characteristics
		6.4	Soil water potential and soil water movement
		6.5	Unsaturated zone; soil moisture constants
		6.6	Infiltration and percolation
		6.7	Groundwater flow; Laplace Equation
	7	Hydraulic conductivity
		7.1	Laboratory measurement
		7.2	Field measurements below the watertable
			7.2.1	Augerhole method
			7.2.2	Piezometer method
			7.2.3	Drain outflow method
		7.3	Field measurements above the watertable
			7.3.1	Infiltrometer-­method
			7.3.2	Inverted augerhole method (Porchet method)
		7.4	Composed K-­values
		7.5	Surveys and data processing
PART III Systems and technology
	8	Subsurface drainage systems
		8.1	Pipe drain systems
		8.2	Deep ditch systems
		8.3	Drainpipes
		8.4	Envelopes
			8.4.1	Envelope need
			8.4.2	Material selection
			8.4.3	Envelope thickness
		8.5	Envelope design guidelines and criteria
			8.5.1	Granular envelopes
			8.5.2	Organic envelopes
			8.5.3	Synthetic envelopes
		8.6	Structures in pipe drain systems
			8.6.1	Surface water inlets
			8.6.2	Inspection, junctions and control
			8.6.3	Crossings
			8.6.4	Outlet of a pipe drain into a ditch or canal
			8.6.5	Sump outlet
		8.7	Construction of pipe drain systems
			8.7.1	Setting out, depth and grade control
			8.7.2	Installation methods and machinery
			8.7.3	Construction and quality control
			8.7.4	Timing of installation
			8.7.5	Installation below the watertable
			8.7.6	Backfill
	9 Surface/shallow drainage systems
		9.1 Bedding systems
		9.2 Shallow ditch systems
			9.2.1 Types of shallow ditch systems
			9.2.2 Some technical aspects of shallow ditch systems
		9.3 Mole drainage systems
		9.4 Pipe drainage systems
		9.5 Complementary measures
			9.5.1 Sub-soiling
			9.5.2 Deep ploughing
			9.5.3 Chemical amendments and organic matter
			9.5.4 Land levelling
	10 Main drainage systems
		10.1 Main features
			10.1.1 Drainage basin (watershed, catchment)
			10.1.2 Types and alignment of drainage canals
			10.1.3 Outlet and water levels
			10.1.4 Outlet structures
		10.2 Lowland and upland drainage
			10.2.1 Lowland polder
			10.2.2 River polders
			10.2.3 Upland discharges
			10.2.4 Drainage of urban areas
PART IV Design
	11 Design of pipe drainage systems
		11.1 Flow patterns
		11.2 Drain spacing formulae
		11.3 Hooghoudt formula
			11.3.1 Use of the Hooghoudt formula
			11.3.2 Notes on the Hooghoudt formula
			11.3.3 Drain spacing determination in anisotropic soils
		11.4 Non-steadystate drainage formulae
			11.4.1 Falling watertable (Glover-Dummformula)
			11.4.2 Fluctuating watertable (de Zeeuw and Hellinga formula)
		11.5 Basic design criteria
			11.5.1 Criteria for off-seasondrainage
			11.5.2 Criteria for crop-seasondrainage
			11.5.3 The impact of drain depth and drainable pore space
			11.5.4 Drainage criteria determined by simulation
		11.6 Drain depth
		11.7 Pipe diameter
	12 Design discharges
		12.1 Discharge transformation
		12.2 Design considerations
		12.3 Statistical analysis of observed discharges
		12.4 Flat basins
			12.4.1 Subsurface drainage
			12.4.2 Shallow drainage
			12.4.3 Further guidance for flat basins
		12.5 Sloping basins
			12.5.1 Rational formula
			12.5.2 Curve number method
			12.5.3 Synthetic hydrographs
		12.6 Area reduction formulae
		12.7 Discharge reduction through storage
			12.7.1 Retention reservoirs
			12.7.2 Canal storage
	13 Design of drainage canals, pumps and structures
		13.1 Drainage canals
			13.1.1 Discharge rate
			13.1.2 Hydraulic gradient and water levels
			13.1.3 Permissible flow velocities
			13.1.4 Cross-section
			13.1.5 Roughness coefficient
			13.1.6 Freeboard
		13.2 Structures in drainage canals
			13.2.1 Culverts and bridges
			13.2.2 Weirs
			13.2.3 Backwater curves
			13.2.4 Example canal design
		13.3 Tidal outlets
			13.3.1 Local variations in tide
			13.3.2 Discharge through a sluice
			13.3.3 Example of calculations
		13.4 Pumps
			13.4.1 Types of pumps
			13.4.2 Pumping head and characteristics
			13.4.3 Pump selection
			13.4.4 Sump and intake design
			13.4.5 Power and cost calculations
			13.4.6 Example cost calculations of an electrically driven pump
PART V Salinity control
	14 Soil salinity
		14.1 Forms of occurrence and distribution of salts in the soil
			14.1.1 The soil solution
			14.1.2 Adsorbed cations
			14.1.3 Equilibrium relationships
			14.1.4 Distribution of salts in the soil
		14.2 Agricultural impacts; diagnosis and assessment
			14.2.1 Osmotic problems
			14.2.2 Toxicity problems
			14.2.3 Dispersion problems
			14.2.4 Corrosion problems
		14.3 Classification
			14.3.1 Classification systems
			14.3.2 Field appearance
		14.4 Conventional mapping and sampling
			14.4.1 Sampling
			14.4.2 Laboratory analysis
		14.5 New salinity measurement and mapping techniques
			14.5.1 The EM38
			14.5.2 Time Domain Reflectometry
			14.5.3 Remote Sensing methods
	15 Irrigation induced salinisation
		15.1 Salinisation by the applied irrigation water
		15.2 Salinisation from the groundwater (capillary salinisation)
			15.2.1 Critical watertable depth
			15.2.2 Factors influencing capillary salinisation
		15.3 Sodification
		15.4 Salt balance of irrigated land
			15.4.1 Leaching requirement calculations
			15.4.2 Regional salt balances
		15.5 Irrigation water quality
			15.5.1 Salinity hazard
			15.5.2 Sodicity hazard
			15.5.3 Toxicity hazards
			15.5.4 Examples of irrigation water quality appraisal
	16 Drainage of irrigated land
		16.1 Waterlogging and salinity
		16.2 Surface drainage
		16.3 Pipe drainage systems
			16.3.1 Drain depth
			16.3.2 Design criteria
			16.3.3 Layout patterns
			16.3.4 Pipe diameter
		16.4 Well or vertical drainage
			16.4.1 Types of aquifers
			16.4.2 Design of well (vertical) drainage
		16.5 Main drainage
			16.5.1 Design discharge
			16.5.2 Disposal of saline drainage water
PART VI Special topics
	17 Seepage and interception
		17.1 Drainage systems for sloping land
			17.1.1 Longitudinal drainage
			17.1.2 Transverse drainage
		17.2 Interception
			17.2.1 Interception of seepage down the slope
			17.2.2 Interception of canal seepage
		17.3 Natural drainage of river valleys
		17.4 Seepage into a polder
			17.4.1 Semi-confinedflow
			17.4.2 Phreatic flow
		17.5 Seep zones and springs
	18 Reclamation and drainage of unripened soils
		18.1 The soil ripening processes
			18.1.1 Physical ripening
			18.1.2 Other ripening processes
		18.2 Reclamation and drainage methods
			18.2.1 Early reclamation stage
			18.2.2 Development of the hydraulic conductivity (K-value)
			18.2.3 Advanced reclamation stage
			18.2.4 Drainage, evaporation and ripening
		18.3 Acid sulphate soils
			18.3.1 Acidification processes
			18.3.2 Neutralisation and reclamation
			18.3.3 Diagnosis
		18.4 Subsidence prediction
			18.4.1 Ripening subsidence
			18.4.2 Settlement subsidence due to lowering of the watertable
			18.4.3 Oxidation of peat soils
			18.4.4 Experiences in the Netherlands
	19 Drainage of rice lands
		19.1 Surface drainage
		19.2 Subsurface drainage
		19.3 Crop diversification
		19.4 Flood control
	20 Controlled drainage
		20.1 Issues and developments
		20.2 Design considerations
			20.2.1 Layout and technical provisions
			20.2.2 Drain depth
			20.2.3 Reuse arrangements
			20.2.4 Discharge control and watertable management
		20.3 Operation and maintenance by farmers
		20.4 Controlled drainage at the regional level
	21 Computer applications
		21.1 Drainage design applications
			21.1.1 Field systems
			21.1.2 Canal systems
			21.1.3 Preparation of drawings and documents
		21.2 Rainfall discharge models
			21.2.1 TR-20model
			21.2.2 HEC-HMS
		21.3 Ground water flow models
			21.3.1 Spreadsheet models
			21.3.2 MODFLOW and integrated programs
			21.3.3 SGMP and SOURCE
		21.4 Agrohydrological models
			21.4.1 DRAINMOD version 6
			21.4.2 SWAP
		21.5 Salinity prediction models
			21.5.1 SALTMOD
			21.5.2 WATSUIT
PART VII Management and New Developments
	22 Research and innovation
		22.1 Hydroluis pipe-envelopedrainage
		22.2 Capiphon drain
		22.3 Precision agriculture for water quality control
		22.4 Bi-levelsubsurface drainage
	23 Institutional, organisational and financial arrangements
		23.1 Drainage laws
		23.2 Development and management models
			23.2.1 Public/private good model
			23.2.2 Participatory development
			23.2.3 Management Transfer
		23.3 Public drainage organisation
		23.4 Financing
			23.4.1 Investments
			23.4.2 Operation and maintenance costs
			23.4.3 Fee systems
	24 Maintenance
		24.1 Classification
		24.2 Organisation, planning and execution
		24.3 Maintenance of open drainage canals
			24.3.1 Problems
			24.3.2 Requirements
			24.3.3 Methods and equipment
			24.3.4 Environmental considerations
		24.4 Maintenance of pipe drains
			24.4.1 Pipe cleaning
			24.4.2 Entry of roots
			24.4.3 Chemical clogging (iron ochre, gypsum)
			24.4.4 Access facilities
			24.4.5 Costs
		24.5 Developing countries
	25 Performance assessment and benchmarking
		25.1 Drainage design and performance
		25.2 Indicators
		25.3 Performance assessment procedure
			25.3.1 Preliminary investigations (first step)
			25.3.2 Primary investigation (second step)
			25.3.3 Cause analysis (third step)
		25.4 Performance checking of pipe systems
		25.5 Causes of under-performanceof drainage systems
References and further reading
Index