A carregar...
Publicação
Reference evapotranspiration estimate with limited weather data across a range of Mediterranean climates
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 1.36 MB | Adobe PDF |
Orientador(es)
Resumo(s)
The standard FAO Penman–Monteith (PM-ETo) method for computing the reference evapotranspiration
(ETo), in addition to air temperature, needs data on solar radiation or sunshine duration, relative humidity
and wind speed which are often lacking and/or do not respect appropriate quality requirements. Hence,
in many cases, ETo has to be estimated with limited weather data using maximum and minimum temperature
only. Essentially, two procedures are used when no more than temperature data are available:
(i) the well-known Hargreaves–Samani equation (HS), or (ii) the PM-ETo method with weather parameters
estimated from the limited available data, called PM temperature (PMT) method. The application of
these temperature-based approaches often led to contradictory results for various climates and world
regions. The data used in the analysis refer to 577 weather stations available through the CLIMWAT database.
The results, confirmed by various statistical indicators, emphasized that: (a) in hyper-arid and arid
zones, the performance of HS and PMT methods are similar, with root mean square errors (RMSEs)
around 0.60–0.65 mm d 1; (b) in semi-arid to humid climates, the PMT method produced better results
than HS, with RMSE smaller than 0.52 mm d 1; (c) the performance of PMT method could be improved
when adopting the corrections for aridity/humidity in the estimation of the dew point temperature from
minimum temperature data. The spatial elaboration of results indicated high variability of ETo estimates
by different methods. Thus, a site-specific analysis using daily datasets of sufficient quality is needed for
the validation and calibration of temperature methods for ETo estimate. Maps presenting indicative
results on under/over estimation of ETo by both temperature methods may be useful for their more accurate
application over different Mediterranean climates
Descrição
Palavras-chave
FAO Penman-Monteith temperature method Hargreaves-Samani equation reference evapotranspiration estimation data correction for aridity data correction for humidity spatial interpolation
Contexto Educativo
Citação
"Journal of Hydrology". ISSN 0022-1694. 481 (2013) p. 166-176