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The spatial variability of the wind in a sprinkler irrigated district: Implications for irrigation management

2011; Elsevier BV; Volume: 109; Issue: 1 Linguagem: Inglês

10.1016/j.biosystemseng.2011.02.003

1537-5129

Inés Sánchez, N. Zapata, J.M. Faci, Antonio Martínez‐Cob,

Plant Water Relations and Carbon Dynamics

The spatial variability of the wind in the Montesnegros Irrigation District (MID), in Spain, has been analysed. From a wind series (2004–2007) registered by a reference weather station, a windspeed >2 m s−1 was observed about 50% of the time. During these periods about 70% of the time it blew from the northwest (known as the Cierzo). Wind was monitored at the reference site and at 17 sites throughout the MID. Using regression a series of the local wind velocities for the irrigation seasons 2004–2007 were estimated from the reference station data. Wind exposure for 39% of the MID area was found to be similar to that of the reference site; 25% were less exposed and 36% considerably more exposed. The spatial variability of the wind was used to calculate the suitable time for irrigation (STI, %) using Ador-Sprinkler software. STI was simulated for different irrigation systems and strategies: standard – Christiansen's uniformity coefficient (CUC) > 84% and wind drift and evaporation losses (WDEL) ≤ 20%, restrictive – CUC ≥ 90% and WDEL ≤ 15% and relaxed – CUC > 80% and WDEL ≤ 25%. At the reference site, STI varied from 50 to 56% of the total time during the irrigation season time for standard strategy, from 68 to 77% for the relaxed strategy and 8 to 30% for the restrictive strategy. Excluding the restrictive strategy, the least exposed sites averaged 14% greater STI than the most exposed sites.