Determination of the resistance to sensible heat flux density from turfgrass for estimation of its evapotranspiration rate
✍ Scribed by Don Johns; C.H.M. Van Bavel; J.B. Beard
- Publisher
- Elsevier Science
- Year
- 1981
- Weight
- 549 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0002-1571
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✦ Synopsis
Johns, D., van Bavel, C.H.M. and Beard, J.B., 1981. Determination of the resistance to sensible heat flux density from turfgrass for estimation of its evapotranspiration rate. Agric. Meteorol., 25: 15--25.
A method of determining the resistance to sensible heat flux density (rh) was tested on a turfgrass canopy in an environmental simulation chamber. The resistance was obtained by determining the rate of change (decay) of temperatures of an abruptly shaded canopy, and is equal to the volumetric heat capacity of air divided by the product of the rate of canopy temperature decay, the mass of leaf tissue per unit area of land surface, and the specific heat capacity of the leaves. Uncertainty analysis showed the mass of leaves per unit area of land surface to be the largest source of error in the determinanation of r h. Values for r h essentially equalled the values for resistance to latent heat flux density determined by three other methods. The application of this method of determining r h to making rapid estimates of evapotranspiration rates was tested in the growth chamber. The estimated values agreed with the measured ones.