|
Titel |
Simultaneously assimilating multivariate data sets into the two-source evapotranspiration model by Bayesian approach: application to spring maize in an arid region of northwestern China |
VerfasserIn |
G. F. Zhu, X. Li, Y. H. Su, K. Zhang, Y. Bai, J. Z. Ma, C. B. Li, X. L. Hu, J. H. He |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1991-959X
|
Digitales Dokument |
URL |
Erschienen |
In: Geoscientific Model Development ; 7, no. 4 ; Nr. 7, no. 4 (2014-07-17), S.1467-1482 |
Datensatznummer |
250115664
|
Publikation (Nr.) |
copernicus.org/gmd-7-1467-2014.pdf |
|
|
|
Zusammenfassung |
Based on direct measurements of half-hourly canopy evapotranspiration (ET;
W m−2) using the eddy covariance (EC) system and daily soil evaporation
(E; mm day−1) using microlysimeters over a crop ecosystem in arid
northwestern China from 27 May to 14 September in 2013, a Bayesian method was
used to simultaneously parameterize the soil surface and canopy resistances
in the Shuttleworth–Wallace (S–W) model. Four of the six parameters showed
relatively larger uncertainty reductions (> 50%), and
their posterior distributions became approximately symmetric with distinctive
modes. There was a moderately good agreement between measured and simulated
values of half-hourly ET and daily E with a linear regression being y =
0.84 x + 0.18 (R2 = 0.83) and y = 1.01 x + 0.01 (R2 = 0.82),
respectively. The causes of underestimations of ET by the S–W model was
possibly attributed to the microscale advection, which can contribute an
added energy in the form of downward sensible heat fluxes to the ET process.
Therefore, the advection process should be taken into account in simulating
ET in heterogeneous land surfaces. Also, underestimations were observed on or
shortly after rainy days, which may be due to direct evaporation of liquid
water intercepted in the canopy. Thus, the canopy interception model should
be coupled to the S–W model in the long-term ET simulation. |
|
|
Teil von |
|
|
|
|
|
|