Deep percolation enhancement from recycled wastewater irrigation maycontribute to salt accumulation and water table elevation that can ultimatelycause soil and ground water degradation. Variation of drainage rate andsolute leaching were investigated in an urban park containing heterogeneouslandscape plants that were irrigated with recycled wastewater. Fieldmonitoring was undertaken at Veale Gardens in the Adelaide Parklands,Australia. Based on landscape variation in Veale Gardens, two landscape zoneswere defined: one being largely covered with turf grasses with few trees andshrubs (MG) with the second zone being mostly trees and shrubs withintermittent turf grasses (MT). Experiments were performed on twozero-tension lysimeters placed horizontally 100 cm below ground to monitorthe variation of volume and quality indicators of drained water for fourseasons. The outcomes showed a significant variation of drainage quantity andquality in the MT and MG zones. The low vegetation cover in the MG zoneresulted in more drained water than in the high vegetation cover (MT zone).In both zones, more drainage water was collected in winter than in otherseasons. This is in spite of the input water showing a maximum rate insummer. The seasonal salinities measured in the two lysimeters showed verysimilar trends with the lowest salinity rate in autumn with the levelsincreasing through winter and spring. Chemical analyses of leachate soluteand salt loading indicated no impact from using recycled wastewater.
展开▼
