A simple single layer model to estimate transpiration from vegetation using multi-spectral and meteorological data
| Autor: | Satya Kalluri, J. R. G. Townshend, P. Doraiswamy |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | International Journal of Remote Sensing. 19:1037-1053 |
| ISSN: | 1366-5901 0143-1161 |
| DOI: | 10.1080/014311698215595 |
| Popis: | A methodology is developed here to model evapotranspiration (λEc ) from the canopy layer over large areas by combining satellite and ground measurements of biophysical and meteorological variables. The model developed here follows the energy balance approach, where λEc is estimated as a residual when the net radiation (Rn), sensible heat flux (H) and ground flux (G) are known. Multi-spectral measurements from the NOAA Advanced Very High Resolution Radiometer (AVHRR) were used along with routine meteorological measurements made on the ground to estimate components of the energy balance. The upwelling long wave radiation, and H from the canopy layer were modelled using the canopy temperature, obtained from a linear relation between the Normalized Difference Vegetation Index (NDVI) and surface temperature. This method separates flux measurements from the canopy and bare soil without the need for a complex two layer model. From theoretical analysis of canopy reflectance, leaf area, and canopy resista... |
| Databáze: | OpenAIRE |
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