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1 Beat Stauffer, seecon international gmbh IrrigationBeat Stauffer, seecon international gmbh
2 Copy it, adapt it, use it – but acknowledge the source! Copyright & DisclaimerCopy it, adapt it, use it – but acknowledge the source!CopyrightIncluded in the SSWM Toolbox are materials from various organisations and sources. Those materials are open source. Following the open-source concept for capacity building and non-profit use, copying and adapting is allowed provided proper acknowledgement of the source is made (see below). The publication of these materials in the SSWM Toolbox does not alter any existing copyrights. Material published in the SSWM Toolbox for the first time follows the same open-source concept, with all rights remaining with the original authors or producing organisations.To view an official copy of the the Creative Commons Attribution Works 3.0 Unported License we build upon, visit This agreement officially states that:You are free to:Share - to copy, distribute and transmit this document Remix - to adapt this document. We would appreciate receiving a copy of any changes that you have made to improve this document.Under the following conditions:Attribution: You must always give the original authors or publishing agencies credit for the document or picture you are using.DisclaimerThe contents of the SSWM Toolbox reflect the opinions of the respective authors and not necessarily the official opinion of the funding or supporting partner organisations.Depending on the initial situations and respective local circumstances, there is no guarantee that single measures described in the toolbox will make the local water and sanitation system more sustainable. The main aim of the SSWM Toolbox is to be a reference tool to provide ideas for improving the local water and sanitation situation in a sustainable manner. Results depend largely on the respective situation and the implementation and combination of the measures described. An in-depth analysis of respective advantages and disadvantages and the suitability of the measure is necessary in every single case. We do not assume any responsibility for and make no warranty with respect to the results that may be obtained from the use of the information provided.
4 1. ConceptIrrigationArtificial application of water to the land to increase crop yield.Necessary in arid areas or during a period of inadequate rainfall.Several methods exist such as:Surface IrrigationManual IrrigationAutomatic IrrigationSprinkler IrrigationDrip IrrigationSubsurface Drip IrrigationSpate IrrigationSprinkler irrigation (“big gun”) in South Canada. Source: STAUFFER 2011
5 Sustainable use of water sources 2. How it can optimise SSWMSustainable use of water sourcesGood operation of any irrigation system includes matching the irrigation duration with the rate of application and the intake rate of the soil to maximise the fraction of water stored in the root zone. HILL et al. (2008)Consider that it is not only your crop field which needs to be watered.Most of the problems with water extraction relate to the proportion of the total available water that is used. NRETAS (2007)Shrinking Aral Sea (from the left to the right); 1989, 2003 and 2011 with the former coast line (thin black line) from Upstream water has been used for cotton production. Source: NASA and USGS (2011)
6 Grey Water Reuse (RODDA et al. 2011) 2. How it can optimise SSWMGrey Water Reuse (RODDA et al. 2011)The greywater tower is especially designed to reuse greywater and produce food. Source: SHEWA and GELETA (2009)Greywater = effluent from baths, showers, kitchen and hand-wash basins and laundry.It can be used both, as irrigation water and as a source of nutrients.Urine FertilisationSeparately collected and hygienised urine is a concentrated source of nutrients.Small-scale application of diluted urine (watering and fertilising at the same time) or adding urine on large agricultural land.Small-scale application of diluted urine with watering can in the Philippines. Source: GENSCH (n.y.)
7 Health Aspects if Irrigated with Waste Water (TILLEY et al. 2008) 2. How it can optimise SSWMHealth Aspects if Irrigated with Waste Water (TILLEY et al. 2008)Proper pre-treatment (pathogen reduction).Households and industry should be made aware of the products (e.g. hazard chemicals) that are and are not appropriate for discharging into the waste water system.Harvested crops and workers should not come in direct contact with such irrigation water.If these rules are considered, waste water (e.g. greywater is a very effective way to recycle nutrients.“Production” of waste water.Pretreatment, e.g. septic tankIrrigation and recycling of nutrients
8 3. Surface Irrigation Design Principles Widely used and well-known. Can be operated without high-tech applications but it is labour intensive.Proper design of irrigation area (e.g. size, slope, levelness) and knowledge about soil type (e.g. texture, intake rate). (HILL 2008)Capital costs (levelling fields, construction of reservoirs) might be expensive. Operational costs are low.Basically three systems:Basin IrrigationBorder IrrigationFurrow Irrigation
9 Basin Irrigation System (WALKER 2003) 3. Surface IrrigationBasin Irrigation System (WALKER 2003)Field must be levelled and encompassed by a dyke.It is favoured by moderate to slow intake soils and deep-rooted, closely spaced crops.Effective method of leaching salts from the soil profile into the deeper groundwater.Can be automated with inexpensive flow controls at the basin inlet.dikes must be well maintained to eliminate breaching and waste.It is difficult and often infeasible to incorporate the use of modem farm machinery in small basins (hand or animal cultivation).A typical surface basin irrigation fields. Source: USU (n.y.)
10 Border Irrigation System (UCCE 2003) 3. Surface IrrigationBorder Irrigation System (UCCE 2003)Expansion of basin irrigation for crops, which do not tolerate flooding.Long, rectangular or contoured field shapes and longitudinal but no lateral slope.field is divided into strips (width of 6 to 30 metres) separated by border ridges.Stripes between ridges are flooded during irrigation.Used for tree crops or crops as alfala or small grains.Tree crops irrigated by a surface border system. Source: UCCE (2005)
11 Furrow Irrigation System (BURT 2000: WALKER 2003) 3. Surface IrrigationFurrow Irrigation System (BURT 2000: WALKER 2003)Constructing small channels (furrows) along the primary direction of water movement.Can be used in conjunction with basins and borders to overcome topographical variation and crusting.More labour intensive than border or basin systems.smaller wetted area can reduce evaporation loss.Salinity hazards, limited machinery mobility and increased erosion potential.Well adapted to row crops and orchards or vineyards.A field irrigated by furrows . Source: HILL et al. (2008)
12 3. Surface Irrigation Costs (WALKER 2003) Construction (only once): Levelling the irrigation area, building the water ditches and reservoir (expensive)Measuring of a single furrow shape. Source: WALKER (2003)Annual Operation Costs:Energy (e.g. filling the reservoirs where necessary), water depreciation, land preparation, maintenance, labour, taxes, etc.
13 Operation & Maintenance (HILL et al. 2008) 3. Surface IrrigationOperation & Maintenance (HILL et al. 2008)The most important to consider in surface irrigation: to move the water to successive application points until it reaches the end of the run.Furrows and stripes must be cleaned out periodically.Leaks in ditches must be repaired immediately, this could be a daily task where rodent damages are a problem.Periodic re-levelling of irrigation field may be needed.
14 Applicability (BURT 2000: WLAKER 2003) 3. Surface IrrigationApplicability (BURT 2000: WLAKER 2003)The system depends on three factors: type of soil, water quality and climate, plant and labours.Permeable soil: difficult to transport the water over the whole field.It can be implemented in windy regions in contrast to sprinkler systems.It is not highly automated, but labour intensive.
15 3. Surface Irrigation Pros and Cons (WALKER 1989) Advantages: Widely used, thus a minimal understanding of the system mostly exists.Water is transported by gravity.Less affected by climatic (wind) and water characteristics (sediment transport).Essential elements are at the edges of the field. This facilitates O&M.It can be developed at the farm level with minimal capital investment.Disadvantages:The soil, which must be used to convey the water over the field, has properties that are highly varied both spatially and temporally.Less efficient in applying water than either sprinkler systems.The need to use the field surface as a conveyance and distribution facility requires that fields be well graded if possible.Surface systems tend to be labour-intensive.
16 Basic Irrigation Principles 4. Manual IrrigationBasic Irrigation PrinciplesHigh labour input and high self-help compatibilityRequire no technical equipment, therefore they are cheapBeside water cans, there more “automated” methods such as:Low-Cost Drip Irrigation SystemPitcher IrrigationBottle IrrigationPorous and Sectioned PipesPerforated Plastic Sleeves
17 4. Manual Irrigation Water Cans Very basic and creates a lot of work on large fields, but widely used.Water can be added on very specific points.Carry poles across the shoulders and a water can at each side facilitates the irrigation work.A rose added to the water can creates a sprinkler effect (see picture).Manual Irrigation with water cans. Source: FAO (2011)
18 Low-Cost Drip Irrigation System 4. Manual IrrigationLow-Cost Drip Irrigation SystemLow-cost plastic pipes laid on the ground and irrigate crops.Small holes in the pipes allow a water to drip out.A water tank on a higher level distributes water by gravity.No waste of water (e.g. evaporation, wind), specific irrigation at the root zone.A low-cost “farm-kit system” with a 1000 litres water tank can service up one-eight of an acre. Source: IPTRID (2008)
19 Pitcher Irrigation (FAO 1997; INFONET-BIOVISION 2010) 4. Manual IrrigationPitcher Irrigation (FAO 1997; INFONET-BIOVISION 2010)Placing porous clay jars (or pots) in shallow pits and soil is packed around.Water can seep slowly out through the porous walls and reach the roots of the plants.Jars can made locally or sweet monkey orange fruit after drying can be used.Jars should be filled regularly and have to be replaced if there are big cracksClay pot irrigation. Source: INFONET-BIOVISION (2010)
20 Bottled Irrigation (INFONET-BIOVISION 2010) 4. Manual IrrigationBottled Irrigation (INFONET-BIOVISION 2010)Similar to pitcher irrigation.The bottle is first filled and than place up side down next to plant.Water is released slowly directly beside the roots.No evaporation or water loss due to windBottled Irrigation is a simple but effective method. Source: INFONET-BIOVISION (2010)
21 Porous and Sectioned Pipes (FAO 1997) 4. Manual IrrigationPorous and Sectioned Pipes (FAO 1997)Instead of pitchers or bottles, porous pipes are used to spread water along a horizontal line.Pipes are placed between crop rowsOne end is made protrude above ground to refill it.This method distributes water over the whole length and not only where it is perforated irrigation effect is lowerSchematic view of porous pipe irrigation. Source FAO (1997)
22 Perforated Plastic Sleeves (FAO 1997) 4. Manual IrrigationPerforated Plastic Sleeves (FAO 1997)Interesting, but not widely used and thus little experience available.A perforated plastic sleeve filled with water is stuck into the ground next to a plant.Needs more research.The plastic sleeve method is not tested systematically and therefore it is difficult to estimate its performance. Source FAO (1997)
23 4. Manual Irrigation Cost All The described methods are very cheap and material is available almost everywhere (old buckets, bottles, etc.)Operation & MaintenanceManual methods in general are labour intensive“Automated” systems (e.g. porous pipes or jars) must be checked and cleaned regularly to avoid water loss, damages or blockages.A man collects water for irrigation with two old buckets fixed on a carry pole. Source: WATERPROJECTLONDON (2010)
24 Applicability (BURT 2000: WLAKER 2003) 4. Manual IrrigationApplicability (BURT 2000: WLAKER 2003)The system depends on three factors: type of soil, water quality and climate, plant and labours.Permeable soil: difficult to transport the water over the whole field.It can be implemented in windy regions in contrast to sprinkler systems.It is not highly automated, but labour intensive.
25 4. Manual Irrigation Pros and Cons (WALKER 1989) Advantages: Improved water-use efficiency (reduced loss through evaporation)Well directed, selective and targeted irrigationEnsures constant water supply in the crucial phase of germinationHigher yields, better quality, higher germination rate, lower incidence of pest attackFacilitates pre-monsoon sowing.Can be constructed with locally available materialLow investment costsDisadvantages:Labour intensiveUser need a basic training to install and use the correct most of the methodIf the water is not properly filtered and the equipment not properly maintained, it can result in clogging.Manual subsurface drip irrigation avoids the high capillary potential of traditional surface applied irrigation, which can draw salt deposits up from deposits below.
26 Basic Design Principles 5. Automatic IrrigationBasic Design PrinciplesOnce it is installed, the irrigation system has not to be controlled all the time.Modern big scale systems operated by one (skilled) labour.Very technical components required. There even high-tech solutions using GIS and satellites to measure water needs.Time Based SystemVolume Based SystemOpen Loop SystemsClosed Loop SystemsReal Time Feedback SystemComputer Based Irrigation Control SystemsThere also simple methods such as clay pot irrigation networks.
27 5. Automatic Irrigation High-Tech Solutions Time Based (RAJAKUMAR et al and IDE n.y.)Time of operation (irrigation time – hrs per day) is calculated according to volume of water (water requirement - litres per day) required and the average flow rate of water (application rate – litres per hours). A timer starts and stops irrigation.Volume Based (RAJAKUMAR et al. 1998)The pre-set amount of water can be applied in the field segments by using automatic volume controlled metering valves.Open Loop System (BOMAN et al. 2006)Open loop controllers normally come with a clock that is used to start irrigation.Termination of the irrigation can be based on a pre-set time or may be based on a specified volume of water passing through a flow meter.
28 5. Automatic Irrigation High-Tech Solutions Closed Loop Systems (BOMAN et al. 2006)This type of system, the feedback and control of the system are done continuously.Closed loop controllers require data acquisition of environmental parameters (such as soil moisture, temperature, radiation, wind-speed, etc) as well as system parameters (pressure, flow, etc.).Simple version of a closed loop system: A moisture sensor interrupts/starts the irrigation process. Source: BOMAN et al. (2006)Real Time Feedback System (RAJAKUMAR et al. 1998)Various sensors, tensiometers, relative humidity sensors, rain sensors, temperature sensors etc. control the irrigation scheduling. These sensors provide feedback to the controller to control its operation
29 5. Automatic Irrigation High-Tech Solutions Computer-based Irrigation Control Systems (RAJAKUMAR et al. 1998)This system consists of a combination of hardware and software that acts as a supervisor with the purpose of managing irrigation and other related practices such as [1995-fertigation] and maintenance.Basically two systems: Interactive and fully automatic systems.Control board showing timers, soil moisture sensor-controllers, solenoid valves wiring, and flowmeters-datalogger. Source: CARDENAS-LAILHACAR (2006)
30 5. Automatic Irrigation Low-Tech Solutions Clay Pot and Porous Capsule Irrigation Network (UNEP 1998)Old system, which was modernised over the years.Low volume irrigation technology.Systems consists of using clay pods and porous capsules.The pots (volume of 10 to 12 litres) are partially buried in the soil with only the top poking out.Distribution is done by PVC pipes.A constant level in the storage reservoir regulates hydrostatic pressure.
31 5. Automatic Irrigation Low-Tech Solutions Clay Pot and Porous Capsule Irrigation Network (UNEP 1998)Schematic representation of a clay pot irrigation system (left) and porous capsule irrigation system (right). Source: UNEP (1998)
32 5. Automatic Irrigation Low-Tech Solutions Automatic Surge Flow and Gravitational Tank Irrigation System (UNEP 1998)Intermittent gravity-flow irrigation system.A siphon replaces expensive electronically controlled valves.Easy to operate and maintain with a minimum consumption of energy.The system consists of a storage tank equipped with one or more siphonsSchematic representation of an automatic surge flow irrigation system. Source: UNEP (1998)
33 5. Automatic Irrigation Cost Costs highly depend on the applied system. It varies from very cheap (e.g. timer) to very expensive systems, which includes research on soil quality and technical material.Operation & MaintenanceOperation by skilled laboursMust be maintained frequently (malfunction of valves or sensors rises costs immediately)ApplicabilityAlmost every irrigation can be automated.It saves time and water.Allows a very efficient irrigation, i.e. metering the water volumes more precisely.
34 5. Automatic Irrigation Pros and Cons (WALKER 1989) Advantages: Eliminates the manual operation of opening or closing valvesPossibility to change frequency of irrigation and fertigation processes and to optimise these processesUse of water from different sources and increased efficiency in water and fertiliser useSystem can be operated at night, water loss from evaporation is thus minimisedIrrigation process starts and stops exactly when required, thus optimising energy requirementsDisadvantages:The systems can be very expensiveSelf-help compatibility is very low with big-scale systems, which are very complexMost automated irrigation systems need electricity
35 6. Sprinkler Irrigation Design Principles Widely used and well-known. Water is distributed through a system of pipes (usually by pumping) and spray heads at the outlets distribute the water over the entire soil surface.This system, especially large ones, are mostly automated.It can be found in small vegetable gardens up to large crop fields. Therefore several systems were developed:Sprinkler headsCentre PivotLinear MoveTravelling Big GunSide Roll
36 6. Sprinkler Irrigation Sprinkler Head Two types: Impact and gear-drive sprinklers.Spray nozzles discharge water and covers typically an area up to 12 m (head-to-head).Single sprinklers can be connected to each other with lateralsLager system are mostly automated (e.g. time based)Used in gardens, pastures and larger lawn areas.A vegetable field irrigated by interconnected sprinkler heads. Source: TRADEINDIA (n.y.)
37 Centre Pivot (SCHERER 2010) 6. Sprinkler IrrigationCentre Pivot (SCHERER 2010)Self-propelled sprinkler system rotates around the pivot point.Amount of applied water is controlled by the moving speed.For any crop height and especially suited for light soils and low labour requirement.“End-gun”, installed at the end of the sprinkler bar, is able to reach corners.The system irrigates an area up to 0.5 km2. Source: SCHERER (2010); STAUFFER (2011)
38 Linear Move (Lateral Move) (SCHERER 2010) 6. Sprinkler IrrigationLinear Move (Lateral Move) (SCHERER 2010)Moving towers and pipes interconnecting the towers which move at the same speed in the same direction.Water is pumped into the centre or into one end.High capital investment, therefore mostly in use for high value crop.The system irrigates rectangular, very large fields, e.g. in the prairies of Alberta, Canada. Source: SCHERER (2010); STAUFFER (2011)
39 Travelling Big Gun (SCHERER 2010) 6. Sprinkler IrrigationTravelling Big Gun (SCHERER 2010)The big gun system uses high water pressure and a large capacity nozzle.The gun is connected either to a hard or flexible hose and is pulled towards the water source.Maximum area to irrigate ranges from 0.3 to 0.4 km2 per gun.Schmatic plan for a big gun irrigation system. Source: SCHERER (2010); STAUFFER (2011)
40 Side Roll (Wheel Roll) (SCHERER 2010) 6. Sprinkler IrrigationSide Roll (Wheel Roll) (SCHERER 2010)Up to a quarter mile long lateral on wheels (diameter 1 to 3 m), water is pumped into one end.When desired amount is applied, lateral is moved forward by a gasoline engine.Should be used on flat ground and low growing crops, moderate initial costsWheel line irrigation system in the south of British Columbia, Canada. Source: SCHERER (2010) and STAUFFER (2011)
41 6. Sprinkler Irrigation Costs Depending on the irrigation method, but the large systems in general incur high capital costs.Energy costs for constant pumping.Considering operation (skilled labours), maintenance (reparations)Operation and MaintenanceOn large systems, expert knowledge might be necessaryPipes/hoses and all mechanical components have to be kept in shape to avoid damage and high repair costs.Small sprinkler systems for gardening are easy to handle for everyone.
42 6. Sprinkler Irrigation Applicability (FAO 1998) Best suited for sandy soils with high infiltration rates, but in general suited for most soil types.Average application rate must lower than the infiltration rate to avoid ponding.Not suitable for soils that easily form a crust or in case of risk of salinisation.Sprinklers that produce a light fine spray should be preferred to avoid damages on crop/soil.
43 6. Sprinkler Irrigation Pros and Cons (WALKER 1989) Advantages No terracing requiredSuitable for almost all types of soilApplication rates and times adaptable to the needs of the plant and soil typeIndependent from the topography of the areaNo need for channels (HOVE 2011).Possibility of adding fertilisers or pesticidesPossibility of irrigating for other purposes: sprouting, frost protection or cooling during hot periods (HOVE 2011)DisadvantagesHigh operation expenses due to the energy need, labour and relatively large investment in equipment (HOVE 2011)Sensitivity to wind, causing evaporation losses (HOVE 2011)The unavoidable wetting of foliage in field crops results in increased sensitivity to diseases (HOVE 2011)Debris and sediments can cause cloggingCapital cost is high with greater operational costs due to higher energy requirements (HOVE 2011)
44 Design Principles (FAO 1988; INFONET-BIOVISION 2010) 7. Drip IrrigationDesign Principles (FAO 1988; INFONET-BIOVISION 2010)Water is conveyed under pressure through a pipe system to the fields.It drips slowly onto the soil through emitters or drippers which are located close to the plants.Only the root zone is wetted.There are very technical systems but also self-made designs.It requires relatively small amounts of water, but it is very effective.Pre-treated waste water or urine can be added as a fertiliser.
45 Commercial Drip Irrigation System (INFONET-BIOVISION 2010) Used in highly technical and industrial farming.Filters are installed to prevent clogging.Fertiliser and chemicals often are mixed into the irrigation waterThe system can be flushed to clean it.Drip irrigation on a large field. Source: WATERWIKI (2009)
46 Commercial Drip Irrigation System Schematic design of a commercial drip irrigation system. This includes technical components such as filters, pumps and hydraulic control valves. Source: INFONET-BIOVISION (2010)
47 Small Scale and Self-Made Drip Irrigation Systems Small initial investment, especially for small scale famers.Can be built with local available material.High self-help compatibility (farmers might need training at the beginning).Wastewater should be pre-treated and filtered to avoid infections and clogging.A self-made irrigation system in Africa with a bucket as a water reservoir and simple plastic hoses for the distribution. If bamboo is available, it can be used as distribution pipes. Source: STANDISH (2009) and INFONET-BIOVISION (2010)
48 Small Scale and Self-Made Drip Irrigation Systems 20 litre bucket, 30 metres of hose which is connected to the tankTank is on a elevation of at least 3 m and refilled daily. The water must be filtered to avoid clogging.Water is distributed by gravity.There are bucket fits available, which is the smallest type of drip irrigation. (RCSD 2008)Schematic Design of a low-cost drip irrigation system.Source: RCSD (2008)
49 7. Drip Irrigation Costs Industrial systems are expensive. Small-scale farmer are able to built a self-made drip system with local available materials.In general more costly than manual irrigation, but improves yields and decrease water use.Operation and Maintenance (INFONET-BIOVISION 2010)Pipes should be anchored to the ground and checked regularly.Leaks must be repaired immediately.Once a month, pipes should be flushed or as soon as clogging is supposed.
50 Applicability (WIKIPEDIA 2011) 7. Drip IrrigationApplicability (WIKIPEDIA 2011)Very appropriate irrigation method, especially in arid and windy areas.It is suitable for using recycled municipal wastewater.There are technical solutions for large farming fields but also very simple systems for small scale farmers.
51 7. Drip Irrigation Pros and Cons Advantages High water application efficiencyMinimised fertiliser/nutrient loss due to localised applicationAbility to irrigate irregular shaped fields.Safe use of recycled (waste-) waterMoisture within the root zone can be maintained at field capacity and minimised soil erosionSoil type plays less important role in frequency of irrigationHighly uniform distribution of waterLow-pressure operationDisadvantagesCommercial system are expensive.The sun can affect the tubes used for drip irrigationRisk of cloggingDrip irrigation might be unsatisfactory if herbicides or top dressed fertilisers need sprinkler irrigation for activationWithout sufficient leaching (most drip systems are designed for high efficiency, meaning little or no leaching fraction), salts applied with the irrigation water may build up in the root zone
52 Design Principles (FAO 1988; INFONET-BIOVISION 2010) 8. Subsurface Drip IrrigationDesign Principles (FAO 1988; INFONET-BIOVISION 2010)Water is conveyed under pressure through a pipe system and applied to the roots below soil surface.No surface crusting or evaporation loss, thus highly efficient irrigation method.Fields can still be worked when irrigation systems are installed and application of fertiliser can optimise plant growthA field irrigated by a subsurface drip system. Source: SMART FERTILIZER MANAGEMENT (2011)
53 Basic Design Principles (REICH 2009) 8. Subsurface Drip IrrigationBasic Design Principles (REICH 2009)Similar design as a common drip irrigation system.Components such as settling ponds, pump, backflow prevention valves, chemical/fertilser injection unit, rtc.Piping is layed 10 to 60 cm below surface, depending on crop and soil.If wastewater is used, pre-treatment is necessary before the settling pond.Generally high-tech and automatically operated system.Simple manual irrigation methods are bottled or porous pipes are also available.
55 8. Subsurface Drip Irrigation CostsEstimated investment costs per acre (industrial agriculture): 1000 to 2000 US$. (REICH 2009)There also several low cost solutions (use local available material and basic methods such as bottle irrigation).Operation and Maintenance (INFONET-BIOVISION 2010)Regular and systematic checks to find damages on pipes as soon as possible.Mechanical components must be maintained regularly.The function of the filter system is crucial for the system, thuis regular inspection is very important.Pipes should be flushed periodically.
56 Applicability (WIKIPEDIA 2011) 8. Subsurface Drip IrrigationApplicability (WIKIPEDIA 2011)Especially suitable for arid, semi-arid, hot, and windy areas with limited water supply.The system is relatively complex, therefore more suitable for medium- to large-scale productionDrip irrigation requires energy to deliver the water. This must be factored into budgets. Source: CRC (n.y.)
57 8. Subsurface Drip Irrigation Pros and ConsAdvantagesHigh degree of control over water application with the potential for high uniformity of applicationEvaporation is reducedFrequent irrigation allows for optimum soil moisture content in the root zoneGreat performance in windy and arid locationsIf pre-treated wastewater is used for irrigation, the risk of direct contact with crops and labourers is reducedDisadvantagesRisk of cloggingsalts accumulate at the wetting front (if water is saline)Emitter can be damaged or blocked by root hairsSuspended organic matter and clay particles can damage the systemA lot of repair work is caused by rodents chewing the tubesHeavy machinery can damage the laterals
58 Introduction (SPATE IRRIGATION NETWORK n.y.) Unique to semi-arid areas (Middle East, North and East Africa, West Asia, parts of Latin America).Water is diverted from riverbeds (Arabian term: wadi) which do not contain water all over the year.Big uncertainty caused by unpredictable floods and changing riverbeds from where water is diverted.Important to respect the water rights of down stream population that conflicts can be avoided.Constructing a large river diversion structure - earthworks and gabions (Wadi Labka, Eritrea). Source: SPATE IRRIGATION NETWORK n.y.)
59 Basic Design Principles (FAO 2010) 9. Spate IrrigationBasic Design Principles (FAO 2010)Basically, a spate irrigation system consists of:Intake areas or canals where stormwater is diverted from the wadi.Sedimentation basins, because of the high sedimentation load.Distribution channels which bring the water to the fields.Overflow to flush the sedimentation basins.The intake should be designed that downstream riparian do have enough water as well.
60 Basic Design Principles (FAO 2010) 9. Spate IrrigationBasic Design Principles (FAO 2010)A large spate irrigation construction in Yemen. It is a big improvement for the delivered area, but also creates conflicts with farmers downstream. Source: FAO (2010)
61 Basic Design Principles – On the Field (FAO 2010) 9. Spate IrrigationBasic Design Principles – On the Field (FAO 2010)Basically, a spate irrigation system consists of:Water, after diverted from the wadi, must be distributed on the field. There are four methods (two groups) to do that:field-to-field distribution or individual field distributionextensive distribution or intensive distributionNote: it is not the same technique as used in surface Irrigation
62 Basic Design Principles – Field to Field Irrigation (FAO 2010) 9. Spate IrrigationBasic Design Principles – Field to Field Irrigation (FAO 2010)Water is diverted to a group of bunded fields.As soon as enough water is applied, the operator cuts the downstream field bund. This is repeated until all fields are irrigated.Alternative: individual inlets from secondary or tertiary canals: higher control on irrigation and single fields can be watered as desired but more construction and land use for canal is necessary.
63 Basic Design Principles – Field to Field Irrigation (FAO 2010) 9. Spate IrrigationBasic Design Principles – Field to Field Irrigation (FAO 2010)A field-to-field distribution in Eritrea. Source: FAO (2010)
64 Basic Design Principles – Extensive / Intensive (FAO 2010) 9. Spate IrrigationBasic Design Principles – Extensive / Intensive (FAO 2010)Extensive: one single irrigation is common over the whole surfaceIntensive: fields may be irrigated twice or three times before cultivation when floods are concentrated on a small areaBoth types can exist in the same system and are dependent on the moisture holding capacity of the soil and crop.If it is watered intensive, crop most be well adjusted to moisture stress.
65 9. Spate Irrigation Costs (NWP 2007) Costs have to be adjusted to the local conditions, project, machinery and material.Usually farmers have to be supported by the government and/or an NGO.Advantages of small-scale spate irrigation systems considering costs:It can be easily maintained.less dependent on heavy machinery and important materials and construction.reparation work can be done by farmers themselves.
66 Operation and Maintenance (EMBAYE 2009; FAO 2010) 9. Spate IrrigationOperation and Maintenance (EMBAYE 2009; FAO 2010)Main problem: floods transport sediments and debris, thus regional climate and hydrology must be well known.Channels and sedimentation basins have to be flushed or cleaned out during the dry season.Field bunds have to be checked/repaired regularly.The fields have to be levelled to guarantee an equally water distribution.Moisture conservation is important to avoid a fast water loss due to evaporation.Farmers removing sediments from the main canal by shovelling. Source: EMBAYE (2009)
67 9. Spate Irrigation Conflicts (FAO 2010) Modernisation often enlarges diversion volume, this leads to upstream/downstream conflicts.Social settings and water rights should be considered (international water rights, regional regulations). This should be controlled by officials.ApplicabilityTypical for semi-arid and arid regions.It is only applicable if there are (seasonal) riverbeds (wadis), which are flooded frequently .Various cropping strategies to cope with the risks in spate irrigation were developed (e.g. drought resistant crop).
68 9. Spate Irrigation Pros and Cons Advantages Big areas can be irrigatedFloods can be controlledIn areas traditionally irrigated by spate irrigations, groundwater source are relatively rich due to long periods of rechargeDisadvantagesUpstream/downstream conflictsSediments in the irrigation water (if they were not removed properly) can cause problems on crops and soilAmount of available water varies from year to yearRiver beds may change and spate irrigation constructions have to be adjustedHydraulically and socially very complexityGreat variability in income between good and bad year
69 8. ReferencesBOMAN, B.; SMITH, S.; TULLOS, B. (2006) Control and Automation in Citrus Microirrigation Systems. Gainesville: University of Florida. URL: [Accessed: ]BURT, C. M. (2000): Selection of irrigation methods for agriculture. Environmental and Water Research Institute. Virginia: ASCE Publications.CARDENAS-LAILHACAR, B. (2006): Sensor-Based Automation of Irrigation of Bermudagrass. Master Thesis. Gainesville: University of Florida. URL: [Accessed: ]CRC (Editor) (n.y.): Healthy Soil Case Study. Sub-Surface Drip Irrigation. Narrabri: Cotton Catchment Communities. URL: [Accessed: ]EMBAYE, T.G. (2009): Analysis of Spate Irrigation Sedimentation and the Design of Settling Basins. Delft: UNESCO-IHE Institute for Water Education (UNESCO-IHE). URL: [Accessed: ]FAO (Editor) (1988): Irrigation Water Management: Irrigation Methods. Rome: Food and Agriculture Organization of the United Nations (FAO). URL: [Accessed: ]FAO (Editor) (1997): Small-scale Irrigation for Arid Zones. Principles and Options. Rom: Food and Agriculture Organisation of the United Nations (FAO). URL: [Accessed: ]FAO (Editor) (2010): Guidelines on Spate Irrigation. Rome: Food and Agriculture Organization (FAO). URL: [Accessed: ]FAO (Editor) (2011): FAO and Emergencies. Rom: Food and Agriculture Organisation of the United Nations (FAO). URL: [Accessed: ]HILL, R.W.; PATTERSON, R.; BARNHILL, J.V. (2008): Small Acreage Irrigation System Operation and Maintenance. Logan: Utah State University. URL: [Accessed: ]HOVE, P.T. (2011): Irrigation Systems: Pros and Cons. [Accessed: ]INFONET-BIOVISION (Editor) (2010): Water for Irrigation. Zürich: Biovision. URL: [Accessed: ]IDE (n.y.): Technical Manual for Ideal Micro Irrigation Systems. Lakewood: International Development Enterprises (IDE). URL: [Accessed: ]IPTRID (Editor) (2008): Grid – IPTRID Network Magazine. February Rome: International Programme for Technology and Research in Irrigation and Drainage (IPTRID). URL: [Accessed: ]
70 8. ReferencesNEIBLING, H.; ROBBINS, J.A. (n.y.): Equipment Selection and Sizing for Sprinkler and Drip Irrigation. Idaho: University of Idaho. URL: [Accessed: ]NASA (Editor) (2011). Aral Sea 1989 and Greenbelt: NASA Goddard Space Flight Center. URL: [Accessed: ]NRETAS (Editor) (2007): Water Extraction. Darwin: Northern Territory Government of Australia (NTA). URL: [Accessed: ]RAJAKUMAR, D.; RAMAH, K.; RATHIKA, S.; THIYAGARAJAN, G. (2008): Automation in Micro-Irigation. New Delhi: Technology Innovation Management and Entrepreneurship Information Service. URL: [Accessed: ]RCSD (Editor) (2008): Low Cost Drip Irrigation Manual. Assam: Resources Centre for Sustainable Development (RCSD). URL: [Accessed: ]REICH, D.; GODIN, R.; CHAVEZ, J.L.; BRONER, I. (2009): Subsurface Drip Irrigation (SDI). Fort Collins: Colorado State University. URL: [Accessed: ]SCHERER, T. (2010): Selecting a Sprinkler Irrigation System. Fargo: North Dakota State University (NDSU). URL: [Accessed: ]SHEWA, W.A.; GELETA, B.G. (2009): Greywater Tower, Arba Minch, Ethiopia. Eschborn: Sustainable Sanitation Alliance (SuSanA). URL: [Accessed: ].SMART FERTILIZER MANAGEMENT (Editor) (2011): URL: [Accessed: ]SPATE IRRIGATION NETWORK (Editor) (n.y.): What is Spate Irrigation? . Hertogenbosch: Spate Irrigation Network. URL: [Accessed: ]STANDISH, S. (2009): How to Irrigate On A Shoestring. Portland: Global Envision. URL: [Accessed: ]TRADEINDIA (n.y.): Sprinkler Irrigation System. URL: (Accessed )UCCE (Editor) (2005): Ground Water Protection Area. Irrigation Systems and their Performance. California. University of California Cooperative Extension (UCCE). URL: [Accessed: ]
71 8. ReferencesUSU (Editor) (n.y.): Introduction to Surface Irrigation Systems. PDF-Presentation. Logan: Utah State University. URL: [Accessed: ]USGS (Editor) (2011). Aral Sea Reston: U.S. Geological Survey (USGS). URL: [Accessed: ]WALKER, W.R. (1989): Guidelines for Designing and Evaluating Surface Irrigation Systems. Food and Agriculture Organization of the United Nations (FAO). URL: [Accessed: ]WATERPROJECTLONDON (2010): Irrigation. WaterProjectLondon Blog. URL: [Accessed: ]WATERWIKI (Editor) (2009): Turkey - Promotion of Drip Irrigation in Sugar Beet Production. WaterWiki. URL: [Accessed: ]WIKIPEDIA (Editor) (2011): Drip Irrigation. URL: [Accessed: ]ZELLA, L.; KETTAB, A.; CHASSERIAUX, G. (2006): Design of a Micro-Irrigation System Based on the Control Volume Method. In: Biotechnology, Agronomy, Society and Environment 10, 163 – 171. URL: [Accessed ]
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