Influence of different variables on living wall irrigation

Influenceofdifferentvariables onlivingwallirrigation LuisPérez‐Urrestarazu GregorioEgea RafaelFernández‐Cañero University ofSeville Researchgroup AGR‐268 Urban greening &biosystems engineering Researchgroup AGR‐268 Urban greening &biosystems engineering • ResearchgroupfromtheUniversityofSeville •WorkingonLivingWalls(LW)since2007 •3prototypesforresearch •ThreepatentsrelatedtoLW •SeveralcommercialLWincollaborationwith Who we are Researchgroup AGR‐268 Urban greening &biosystems engineering ExampleofprojectsinvolvingLW: •IrrigationandlightingsystemsforLW •ActiveLWbiofilter &coolingsystem •InfluenceofLWinindoortemperature •SubstrateanalysisforLW •Aquaponics •Leonardotransferofinnovation Who we are Urban greening &biosystems engineering Researchgroup AGR‐268 Introduction •Completelydifferentfromaconventionalirrigation. DistinctiveFeatures: •Verticalmovementofwater •Percolation=runoff •Prevalenceofelevationoverheadlosses •Mixtureoflocalisedandsurfaceirrigation •Difficultyforadaptingtospecieswithdifferentwater requirements:problemstoestablishhydrozones •DesignhighlydependentontheLWsystemused Urban greening &biosystems engineering ResearchgroupAGR‐268 Introduction •System completely vertical low water storage capacity (especially in cloth) •Only water retained by the substrate is available for plants kept permanently wet •Irrigation requirements highly variable depending on several factors: • location (outdoors or indoors) • light exposition (direct sun light, shading…) • temperature and humidity conditions • functional type (passive or active) • vegetation and substrate used •Example: water consumption of an indoor PLW 3to5lm ‐2day‐1over the warm season in southern Spain (Fernández‐Cañero et al. 2011) Urban greening &biosystems engineering Researchgroup AGR‐268 Introduction Water use Lostsolution (‘Runtowaste’systems) Recirculationsystems: reducewaterlossesand simplifyirrigationscheduling, butrequireamorecomplex infrastructure. Greenfacade PassiveLW ActiveLW Indoor Outdoor Type oflivingwall Urban greening &biosystems engineering Researchgroup AGR‐268 Introduction •Panels ‐Irrigationforeachpanel ‐Higherwaterretentioncapacity ‐Morelateraldiffusion: broaderwettedarea •Cloth ‐Moreemittersdensity ‐Moreverticalwaterflow Urban greening &biosystems engineering Researchgroup AGR‐268 Introduction Activesystem •Higherflowrequirements •Nozzlescanbeinstalledinsidethe structure •Substratewithverylowwater retentioncapacity •Higherirrigationfrequency (thesubstratedriesoutfaster) Urban greening &biosystems engineering ResearchgroupAGR‐268 Introduction •Several ways of applying water, most common drip lines at different heights water can move vertically and laterally in‐between lines by gravity and lateral diffusion •Design variables: emitters and drip line spacing and emitter type and flow •Operational variables: irrigation duration and frequency, depending on: • type of living wall (indoor/outdoor, passive/active) • system design variables • environmental conditions (sunlight exposition, evapotranspiration…) •Challenge: achieving a high degree of water uniformity in the entire wall while minimizing water losses Urban greening &biosystems engineering ResearchgroupAGR‐268 Results •Run‐offtest GT (a) 8l/h (b) 4l/h (c) 4‐2l/h (d) 2l/h Urban greening &biosystems engineering ResearchgroupAGR‐268 Results •Run‐offtestGT • tendencytowardslowerretentionvalueswithhigherflows •4l/hand4‐2l/hhadaverysimilarperformance •lesswaterretainedwhenusingdoubleemitterspacing •2l/hlowerrun‐offlossesandhighervolumeofwaterretained Urban greening &biosystems engineering ResearchgroupAGR‐268 Results •Run‐offtestGT Effectofinitialmoisturecontent: •Highertotalrun‐offandpeak valueunderinitialwet conditions •BUTduringthefirstminutesof irrigation,run‐offrateandthus waterlostwashigherunder initialdryconditions Urban greening &biosystems engineering ResearchgroupAGR‐268 Results •Run‐offtest PA (a) 8l/h (b) 4l/h (c) 4‐2l/h (d) 2l/h Urban greening &biosystems engineering ResearchgroupAGR‐268 Results •Uniformitytest a) b) c) Driplines Exampleofasetofimagestakenfor4l/hinGTbefore(a),during(b)andafter(c) anirrigationevent Urban greening &biosystems engineering ResearchgroupAGR‐268 Results •Uniformity test S Dvaluesindicate m oisturevariability s suniformity) S Dvaluesindicate m oisturevariability s suniformity) M MIvaluesdenote r averagemoisture M MIvaluesdenote r averagemoisture Urban greening &biosystems engineering ResearchgroupAGR‐268 Results •Irrigation event duration •Irrigation lengths used in this experiment, optimal in terms of water retention but not if run‐off losses are considered  recirculation •Retention curve patterns showed an inflection point before reaching maximum duration •Shorter irrigation lengths are advised •Optimum times depend on slopes of cumulative run‐off and retention curves, and water distribution uniformity attained (denoted by the MMI and SD curves) Urban greening &biosystems engineering ResearchgroupAGR‐268 1. Considerable differences between GT and PA substrates in terms of water retention and distribution uniformity 2. Difficulty to determine irrigation uniformity Thermal imaging and MI as an indicator of the substrate moisture content 3. Distribution uniformity higher in the lower parts of the living wall plan species selection (the lower section will retain more water) 4. When water is not reused, 2 l/h emitters with standard emitter and pipeline spacing (highest water retention capacity though less uniformity) Conclusions Urban greening &biosystems engineering ResearchgroupAGR‐268 5. Double emitter or drip line spacing not advisable with 2 l/h 6. Recirculation systems 8 l/h emitters installed on standardspaced (1 m) pipelines: highest distribution uniformity 7. When using PA, only recirculation systems are recommended, 4 l/h 8. Good irrigation strategy: shorten the irrigation events by applying water when the substrate is still relatively wet 9. For larger living walls, pressure compensating emitters Conclusions Formoreinformation: Perez‐Urrestarazu, Luis; Egea, Gregorio; Franco‐Salas, Antonio; Fernandez‐Cañero, Rafael. 2014. Irrigation systems evaluation for living walls. Journal of Irrigation and Drainage Engineering 140 (4): 04013024‐1/11 Researchgroup AGR‐268 Urban greening &biosystems engineering Influenceofdifferentvariablesonlivingwallirrigation E‐mailcontact: lpere[email protected]