Journal of Agricultural Science and Technology
Journal of Agricultural Science and Technology
JAST
Agriculture
http://jast.modares.ac.ir
1
admin
1680-7073
2345-3737
10.22034/jast
en
jalali
1391
8
1
gregorian
2012
11
1
14
6
online
1
fulltext
en
Predicting Daily Reference Evapotranspiration in a Humid Region of China by the Locally Calibrated Hargreaves-Samani Equation Using Weather Forecast Data
The Hargreaves-Samani (HS) equation, which estimates reference evapotranspiration (ET0) using only temperature as input, should be most suitable for <em>ET</em>0 prediction based on weather forecasting data. In the current study, the HS equation is calibrated with daily <em>ET</em>0 by the Penman-Monteith equation, and is evaluated to check the possibility of predicting daily <em>ET</em>0 based on weather forecast data. The HS equation is likely to overestimate daily <em>ET</em>0 in the humid regions of China. Coefficients <em>a</em> and <em>c </em>are calculated as 0.00138 and 0.5736 according to local calibration. The calibrated HS equation performs considerably better than the original one. The proposed equation could be an alternative and effective solution for predicting daily <em>ET</em>0 using public weather forecast data as inputs. The error of daily <em>ET</em>0 prediction increases with the increase in the error of daily temperature range (TR<em>) </em>or daily mean temperature (Tmean). This error is likely to be more sensitive to the error in <em>TR</em> than in the <em>T</em>mean. Ensuring that <em>TR</em> errors are less than 2°C is necessary for perfect estimations of <em>ET</em>0 based on public weather forecast data using the calibrated HS equation.
Hargreaves-Samani equation,Humid region,Local calibration,Reference evapotranspiration,Sensitivity Analysis,Weather forecast data
1331
1342
http://jast.modares.ac.ir/browse.php?a_code=A-23-1000-3635&slc_lang=en&sid=23
J. Z.
Xu
J. Z.
Xu
100319475328460046294
100319475328460046294
No
Hohai University
Hohai University
S. Z.
Peng
S. Z.
Peng
100319475328460046293
100319475328460046293
Yes
Hohai University
Hohai University
S. H.
Yang
S. H.
Yang
100319475328460046295
100319475328460046295
No
Hohai Univerisity
Hohai Univerisity
Y. F.
Luo
Y. F.
Luo
100319475328460046296
100319475328460046296
No
Hohai univeistiy
Hohai univeistiy
Y. J.
Wang
Y. J.
Wang
100319475328460046297
100319475328460046297
No
Hohai University
Hohai University