Title of article :
Assessment of reference evapotranspiration using remote sensing and forecasting tools under semi-arid conditions
Author/Authors :
M. Cruz-Blanco، نويسنده , , M. and Gavilلn، نويسنده , , P. and Santos، نويسنده , , C. and Lorite، نويسنده , , I.J.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2014
Pages :
10
From page :
280
To page :
289
Abstract :
Reference evapotranspiration (ETo) assessment at regional scale is a challenge to agricultural and hydrological research requiring the characterization of vast areas to obtain accurate meteorological variables. To account for this, a new approach considering a modified version of the Makkink equation and based on a combination of remotely sensed solar radiation (Rs) considering the MSG satellite, and numerical weather forecast of near surface air temperature (T2m), was developed. The new approach is referred as Makkink-Advection equation (MAK-Adv). s and T2m were validated for the semiarid conditions registered in Southern Spain with very satisfactory results (RMSE = 1.6 MJ m−2 d−1 and 1.4 °C respectively, with linear regressions with slope = 0.99 and R2 = 0.97), the MAK-Adv approach was calibrated and validated with ETo measurements from a weighing lysimeter under near-reference conditions in Southern Spain. The new approach has provided accurate daily ETo estimations compared with lysimeter data (RMSE = 0.50 mm d−1, RE = 12.3% and MAE = 0.39 mm d−1), and remains accurate during summer time (RMSE = 0.62 mm d−1 and RE = 9%), the critical period when accurate ETo data are essential for a correct agricultural water management. alibrated and validated, and thanks to the use of remotely sensed data, the MAK-Adv approach allowed the ETo assessment at regional scale. For a semi-arid region located in southern Spain with an area of 87,300 km2, a detailed spatial ETo assessment was performed, determining ETo values for the totality of the area with a resolution of about 9 km2 allowing to evaluate the spatial and temporal variability at basin/region scale. This new approach gets over the serious limitations for a correct ETo assessment when traditional methodologies are not able to provide these data for vast areas, even with the modern weather station networks. Thus, MAK-Adv approach is especially useful for those areas with missing or inaccurate meteorological in situ observations.
Keywords :
Reference evapotranspiration , Remote sensing , MSG , ECMWF , lysimeter , Advection
Journal title :
International Journal of Applied Earth Observation and Geoinformation
Serial Year :
2014
Journal title :
International Journal of Applied Earth Observation and Geoinformation
Record number :
2379729
Link To Document :
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