Irrigation performance in private urban landscapes: A study case in Zaragoza (Spain)

Abstract

a b s t r a c tIrrigation water use in private landscapes represents an increasing share of total water use in semiarid areas. In this work, 102 households located in the Montecanal neighbourhood (Zaragoza, Spain) were analysed. Research took advantage of the dual water supply network (separate indoor and irrigation water networks). The analysis was based on bi-monthly water billing records for the period 2005-2007. The total household landscape area (93 m 2 ) and the area occupied by turf, trees and shrubs were derived from aerial photographs. A method based on reference evapotranspiration was used to estimate net landscape irrigation requirements. The total average water use was 0.80 m 3 household −1 day −1 , with irrigation water use amounting to 46% of the total water use. Average air temperature largely determined irrigation water use (the correlation coefficient was 0.958). Overirrigation was common in the three years of study, with the average irrigation water application (IWA) being much higher than the Net Irrigation Requirements (1359 and 555 mm, respectively). Only 34% of the households showed adequate irrigation, while 6% of the households underirrigated their landscape areas. In the rest of the households (60%), overirrigation was observed. Significant time correlations were found for IWA and for an adequacy index, suggesting that landowners applied their inadequate irrigation criteria in a consistent way. Local private landscape irrigation performance was found to be very poor, probably owing to low water cost and over-the-average household income.

High Spatial Resolution WorldView-2 Imagery for Mapping NDVI and Its Relationship to Temporal Urban Landscape Evapotranspiration Factors

“…In WUCOLS, which is the first of the field-based methods, K L is determined by multiplying species, density and microclimate factors to determine the overall landscape coefficient [47][48][49].…”

An approach to costs and energy consumption in private urban Spanish Mediterranean landscapes from a simplified model in sprinkle irrigation

“…However, domestic gardens are usually over irrigated (Endter-Wada et al, 2008), although Salvador et al (2011) highlight that a water deficit occurs during the summer period as a result of Spanish holiday habits. Considering different irrigation schedule criteria would not alter the order of the designs according to energy consumption.…”

“…The values assumed for these factors were k s = 0.82, corresponding to turf (Salvador et al, 2011), k d = 1 (average density) and k mc = 0.9 (low, assuming that the garden is protected from the wind by nearby buildings and in most cases by perimeter fences, which will throw shadow onto the garden surface). The value for the landscape coefficient was 0.738, and the irrigation water doses were 495.4 and 1,174.7 L m -2 yr -1 for Girona and Elche, respectively.…”

“…These effects, detected in Anglo-Saxon countries, include an increase in energy consumption and emissions (Newman & Kenworthy, 1989;Anderson et al, 1996;Crane, 1999;Lavière & Lafrance, 1999), as well as higher water consumption. On the other hand, in Spain, garden irrigation usually uses potable water, which costs more than water used for agricultural irrigation (Salvador et al, 2011), and consumes a considerable amount of energy, related to the process of obtaining it.…”

Urban Irrigation Challenges and Conservation

“…For example, Ferguson (1987) reported that 40 to 70% of residential water use in the United States was for landscapes but urban water use in the Ebro basin in Spain was only 7% which was mainly in cases of drought (Salvador et al 2011). …”