TY - BOOK AU - Vlotman, Willem F. AU - Smedema, Lambert K. AU - Rycroft, David W. TI - Modern land drainage: planning, design and management of agricultural drainage systems SN - 9781003025900 U1 - 631.62 23 PY - 2020///. CY - Boca Raton, London, New York : PB - CRC press KW - Water Resources KW - Drainage systems KW - Irrigation N1 - Contents List of tables xv List of figures xix List of boxes xxv Preface xxvii About the authors xxix PART I Introduction 1 1 Land drainage for agriculture 3 1.1 Drainage objectives; Scope of the book 5 1.2 Global drainage zones 8 1.2.1 Temperate zone 8 1.2.2 Arid and semi-arid zone 9 1.2.3 Humid and semi-humid zone 9 1.3 Agro-hydrological regimes 9 1.4 Waterlogging control 11 1.4.1 Positive and adverse impacts 11 1.4.2 Responses to improved drainage 13 1.5 Salinity control 17 1.6 Drainage systems 17 1.7 Bio-drainage 19 1.8 Environmental impacts 20 1.8.1 Stream flow regimes 21 1.8.2 Water quality 21 1.8.3 Wetlands and conservation drainage 24 1.8.4 Public health 28 1.9 Drainage development considerations 28 2 Planning and design considerations 31 2.1 Design rainfall 33 2.2 Percolation of excess irrigation water 37 vi Contents 2.3 Design of field drainage systems 38 2.4 Determination of design criteria 39   3   Remote   sensing  and  field  reconnaissance  41 3.1 Need for drainage and problem diagnosis 41 3.2 Remote sensing and aerial survey 42 3.3 Field investigations 44 3.4 Planning stakeholder engagement 44 3.5 Stages of project preparation 45 3.6 Operation, management and maintenance 46 4 Assessment of costs 49 4.1 Required information 49 4.2 Discounting 51 4.3 Evaluation indices 52 4.4 Cost evaluation of open and pipe drainage systems incl. O&M 52 4.5 Cost calculations for pipe drainage systems 54 PART II 4.5.1 Cost structure for pipe drainage construction 54 4.5.2 Guidelines for cost calculations 54 4.5.3 Example cost calculation 55 Investigations 57 5 Climate, land, soil and environment 59 5.1 Climate 59 5.1.1 Climate; soil moisture balance calculations 59 5.1.2 Climate: rainfall depth-duration-frequency studies 62 5.2 Topography 62 5.3 Soil and land conditions 63 5.4 Soil parameters and properties 65 5.4.1 Texture 65 5.4.2 Plasticity index 68 5.4.3 Bulk density and soil moisture content 69 5.4.4 Sample quantity and density 70 5.4.5 Data requirement for drain envelope design 70 5.5 Watertable and groundwater 71 5.5.1 Watertable observation wells 71 5.5.2 Piezometric studies 72 5.5.3 Groundwater sampling 73 5.6 Hydrology and geohydrology 74 5.6.1 Runoff and flooding 74 5.6.2 Outlet conditions 74 5.6.3 Geohydrological conditions 74 5.7 Agriculture and irrigation 75 5.8 Pilot areas and field testing 75 5.8.1 Types of pilot areas 76 5.8.2 Analysis of results of pilot areas 77 5.8.3 Visual drainage need assessment 77 5.8.4 Statistical analysis 78 5.9 Environmental impact 79 5.9.1 Environmental impact assessment 80 5.9.2 Miscellaneous investigations 80 6 Water in the soil 83 6.1 Forms and nature of occurrence of water in the soil 83 6.2 Pressures in the soil water 85 6.3 Soil moisture characteristics 86 6.4 Soil water potential and soil water movement 88 6.5 Unsaturated zone; soil moisture constants 90 6.6 Infiltration and percolation 92 6.7 Groundwater flow; Laplace Equation 94 7 Hydraulic conductivity 97 7.1 Laboratory measurement 98 7.2 Field measurements below the watertable 100 7.2.1 Augerhole method 100 7.2.2 Piezometer method 105 7.2.3 Drain outflow method 106 7.3 Field measurements above the watertable 108 7.3.1 Infiltrometer-method 108 7.3.2 Inverted augerhole method (Porchet method) 110 7.4 Composed K-values 111 7.5 Surveys and data processing 113 PART III Systems and technology 117 8 Subsurface drainage systems 119 8.1 Pipe drain systems 120 8.2 Deep ditch systems 123 8.3 Drainpipes 124 8.4 Envelopes 129 8.4.1 Envelope need 129 8.4.2 Material selection 133 8.4.3 Envelope thickness 135 Contents vii viii Contents 8.5 Envelope design guidelines and criteria 136 8.5.1 Granular envelopes 136 8.5.2 Organic envelopes 140 8.5.3 Synthetic envelopes 140 8.6 Structures in pipe drain systems 144 8.6.1 Surface water inlets 144 8.6.2 Inspection, junctions and control 144 8.6.3 Crossings 146 8.6.4 Outlet of a pipe drain into a ditch or canal 146 8.6.5 Sump outlet 146 8.7 Construction of pipe drain systems 149 8.7.1 Setting out, depth and grade control 149 8.7.2 Installation methods and machinery 151 8.7.3 Construction and quality control 156 8.7.4 Timing of installation 157 8.7.5 Installation below the watertable 157 8.7.6 Backfill 158 9 Surface/shallow drainage systems 161 9.1 Bedding systems 162 9.2 Shallow ditch systems 164 9.2.1 Types of shallow ditch systems 164 9.2.2 Some technical aspects of shallow ditch systems 169 9.3 Mole drainage systems 172 9.4 Pipe drainage systems 175 9.5 Complementary measures 176 9.5.1 Sub-soiling 176 9.5.2 Deep ploughing 178 9.5.3 Chemical amendments and organic matter 178 9.5.4 Land levelling 178 10 Main drainage systems 179 10.1 Main features 179 10.1.1 Drainage basin (watershed, catchment) 180 10.1.2 Types and alignment of drainage canals 181 10.1.3 Outlet and water levels 183 10.1.4 Outlet structures 185 10.2 Lowland and upland drainage 187 10.2.1 Lowland polder 187 10.2.2 River polders 188 10.2.3 Upland discharges 190 10.2.4 Drainage of urban areas 191 PART IV Design 193 11 Design of pipe drainage systems 195 11.1 Flow patterns 195 11.2 Drain spacing formulae 199 11.3 Hooghoudt formula 200 11.3.1 Use of the Hooghoudt formula 201 11.3.2 Notes on the Hooghoudt formula 201 11.3.3 Drain spacing determination in anisotropic soils 204 11.4 Non-steady state drainage formulae 205 11.4.1 Falling watertable (Glover-Dumm formula) 206 11.4.2 Fluctuating watertable (de Zeeuw and Hellinga formula) 209 11.5 Basic design criteria 212 11.5.1 Criteria for off-season drainage 212 11.5.2 Criteria for crop-season drainage 214 11.5.3 The impact of drain depth and drainable pore space 217 11.5.4 Drainage criteria determined by simulation 217 11.6 Drain depth 218 11.7 Pipe diameter 221 12 Design discharges 227 12.1 Discharge transformation 227 12.2 Design considerations 231 12.3 Statistical analysis of observed discharges 233 12.4 Flat basins 234 12.4.1 Subsurface drainage 235 12.4.2 Shallow drainage 237 12.4.3 Further guidance for flat basins 239 12.5 Sloping basins 240 12.5.1 Rational formula 240 12.5.2 Curve number method 244 12.5.3 Synthetic hydrographs 246 12.6 Area reduction formulae 249 12.7 Discharge reduction through storage 250 12.7.1 Retention reservoirs 251 12.7.2 Canal storage 256 13 Design of drainage canals, pumps and structures 261 13.1 Drainage canals 261 13.1.1 Discharge rate 263 13.1.2 Hydraulic gradient and water levels 265 Contents ix x Contents 13.1.3 Permissible flow velocities 267 13.1.4 Cross-section 267 13.1.5 Roughness coefficient 268 13.1.6 Freeboard 268 13.2 Structures in drainage canals 270 13.2.1 Culverts and bridges 270 13.2.2 Weirs 271 13.2.3 Backwater curves 272 13.2.4 Example canal design 274 13.3 Tidal outlets 276 13.3.1 Local variations in tide 276 13.3.2 Dischar ge through a sluice 278 13.3.3 Example of calculations 279 13.4 Pumps 280 13.4.1 Types of pumps 282 13.4.2 Pumping head and characteristics 283 13.4.3 Pump selection 285 13.4.4 Sump and intake design 287 13.4.5 Power and cost calculations 287 13.4.6 Example cost calculations of an electrically driven pump 288 PART V Salinity control 291 14 Soil salinity 293 14.1 Forms of occurrence and distribution of salts in the soil 293 14.1.1 The soil solution 295 14.1.2 Adsorbed cations 295 14.1.3 Equilibrium relationships 297 14.1.4 Distribution of salts in the soil 298 14.2 Agricultural impacts; diagnosis and assessment 298 14.2.1 Osmotic problems 299 14.2.2 Toxicity problems 304 14.2.3 Dispersion problems 306 14.2.4 Corrosion problems 307 14.3 Classification 308 14.3.1 Classification systems 308 14.3.2 Field appearance 310 14.4 Conventional mapping and sampling 311 14.4.1 Sampling 311 14.4.2 Laboratory analysis 312 14.5 New salinity measurement and mapping techniques 315 14.5.1 The EM38 316 14.5.2 Time Domain Reflectometry 316 14.5.3 Remote Sensing methods 317 15 Irrigation induced salinisation 319 15.1 Salinisation by the applied irrigation water 319 15.2 Salinisation from the groundwater (capillary salinisation) 320 15.2.1 Critical watertable depth 321 15.2.2 Factors influencing capillary salinisation 321 15.3 Sodification 323 15.4 Salt balance of irrigated land 323 15.4.1 Leaching requirement calculations 326 15.4.2 Regional salt balances 327 15.5 Irrigation water quality 328 15.5.1 Salinity hazard 329 15.5.2 Sodicity hazard 330 15.5.3 Toxicity hazards 331 15.5.4 Examples of irrigation water quality appraisal 332 16 Drainage of irrigated land 335 16.1 Waterlogging and salinity 335 16.2 Surface drainage 336 16.3 Pipe drainage systems 338 16.3.1 Drain depth 339 16.3.2 Design criteria 341 16.3.3 Layout patterns 345 16.3.4 Pipe diameter 347 16.4 Well or vertical drainage 348 16.4.1 Types of aquifers 348 16.4.2 Design of well (vertical) drainage 350 16.5 Main drainage 351 16.5.1 Design discharge 352 16.5.2 Disposal of saline drainage water 352 PART VI Special topics 355 17 Seepage and interception 357 17.1 Drainage systems for sloping land 357 17.1.1 Longitudinal drainage 358 17.1.2 Transverse drainage 358 17.2 Interception 360 17.2.1 Interception of seepage down the slope 360 17.2.2 Interception of canal seepage 362 Contents xi xii Contents 17.3 Natural drainage of river valleys 363 17.4 Seepage into a polder 364 17.4.1 Semi-confined flow 364 17.4.2 Phreatic flow 366 17.5 Seep zones and springs 367 18 Reclamation and drainage of unripened soils 369 18.1 The soil ripening processes 369 18.1.1 Physical ripening 369 18.1.2 Other ripening processes 371 18.2 Reclamation and drainage methods 371 18.2.1 Early reclamation stage 371 18.2.2 Development of the hydraulic conductivity (K-value) 372 18.2.3 Advanced reclamation stage 372 18.2.4 Drainage, evaporation and ripening 373 18.3 Acid sulphate soils 374 18.3.1 Acidification processes 374 18.3.2 Neutralisation and reclamation 374 18.3.3 Diagnosis 375 18.4 Subsidence prediction 375 18.4.1 Ripening subsidence 376 18.4.2 Settlement subsidence due to lowering of the watertable 376 18.4.3 Oxidation of peat soils 378 18.4.4 Experiences in the Netherlands 378 19 Drainage of rice lands 381 19.1 Surface drainage 381 19.2 Subsurface drainage 386 19.3 Crop diversification 387 19.4 Flood control 388 20 Controlled drainage 391 20.1 Issues and developments 391 20.2 Design considerations 392 20.2.1 Layout and technical provisions 393 20.2.2 Drain depth 395 20.2.3 Reuse arrangements 396 20.2.4 Discharge control and watertable management 397 20.3 Operation and maintenance by farmers 400 20.4 Controlled drainage at the regional level 403 21 Computer applications 405 21.1 Drainage design applications 405 21.1.1 Field systems 406 21.1.2 Canal systems 406 21.1.3 Preparation of drawings and documents 408 21.2 Rainfall discharge models 408 21.2.1 TR-20 model 409 21.2.2 HEC-HMS 409 21.3 Ground water flow models 409 21.3.1 Spreadsheet models 410 21.3.2 MODFLOW and integrated programs 410 21.3.3 SGMP and SOURCE 410 21.4 Agrohydrological models 411 21.4.1 DRAINMOD version 6 412 21.4.2 SWAP 413 21.5 Salinity prediction models 414 21.5.1 SALTMOD 414 21.5.2 WATSUIT 415 PART VII Management and New Developments 417 22 Research and innovation 419 22.1 Hydroluis pipe-envelope drainage 419 22.2 Capiphon drain 420 22.3 Precision agriculture for water quality control 420 22.4 Bi-level subsurface drainage 421 23   Institutional,  organisational   and  financial  arrangements   425 23.1 Drainage laws 425 23.2 Development and management models 426 23.2.1 Public/private good model 426 23.2.2 Participatory development 426 23.2.3 Management Transfer 428 23.3 Public drainage organisation 428 23.4 Financing 430 23.4.1 Investments 430 23.4.2 Operation and maintenance costs 431 23.4.3 Fee systems 431 24 Maintenance 435 24.1 Classification 435 24.2 Organisation, planning and execution 436 24.3 Maintenance of open drainage canals 436 24.3.1 Problems 436 24.3.2 Requirements 437 Contents xiii xiv Contents 24.3.3 Methods and equipment 440 24.3.4 Environmental considerations 442 24.4 Maintenance of pipe drains 442 24.4.1 Pipe cleaning 443 24.4.2 Entry of roots 444 24.4.3 Chemical clogging (iron ochre, gypsum) 444 24.4.4 Access facilities 445 24.4.5 Costs 446 24.5 Developing countries 446 25 Performance assessment and benchmarking 449 25.1 Drainage design and performance 449 25.2 Indicators 450 25.3 Performance assessment procedure 452 25.3.1 Preliminary investigations (first step) 453 25.3.2 Primary investigation (second step) 453 25.3.3 Cause analysis (third step) 453 25.4 Performance checking of pipe systems 454 25.5 Causes of under-performance of drainage systems 455 References and further reading 457 Index 473 UR - file:///C:/Users/Busitema/Downloads/Modern%20Land%20Drainage%20Planning,%20Design%20and%20Management%20of%20Agricultural%20Drainage%20Systems,%202nd%20Edition%20(Willem%20F.%20Vlotman)%20(z-lib.org)%20(1).pdf ER -