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ARS Home » Pacific West Area » Boise, Idaho » Northwest Watershed Research Center » Research » Publications at this Location » Publication #206793

Title: Radiative transfer modeling of a coniferous canopy characterized by airborne remote sensing

item ESSERY, R
item HARDY, J
item LINK, T
item Marks, Daniel
item MELLOH, R
item RUTTER, N

Submitted to: Journal of Hydrometeorology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2008
Publication Date: 3/1/2008
Citation: Essery, R., Bunting, P., Hardy, J., Link, T., Marks, D.G., Melloh, R., Pomeroy, J., Rowlands, A., Rutter, N. 2008. Radiative Transfer Modeling of a Coniferous Canopy Characterized by Airborne Remote Sensing. Journal of Hydrometeorology, 9, 228-241, doi:10.1175/2007JHM870.1.

Interpretive Summary: Modeling the effect of different canopy types on solar radiation requires detailed maps of canopy structure. Canopy structure maps derived from a combination of aerial photography and airborne LiDAR data are used to model radiation transfer to the ground. These simulations are then compared to measured values using an array of solar radiometers. Results show that LiDAR data can be effective in predicting canopy structure, including tree height, spacing, and gap distribution. This work will lead to improved application of LiDAR data for managing forests and water resources.

Technical Abstract: Solar radiation beneath a forest canopy can have large spatial variations, but his is frequently neglected in radiative transfer models for large-scale applications. To explicitly model spatial variations in sub-canopy radiation, maps of canopy structure are required. Aerial photography and airborne laser scanning are used to map tree locations, heights and crown diameters for a lodgepole pine forest in Colorado as inputs to a spatially-explicit radiative transfer model. Statistics of sub-canopy radiation simulated by the model are compared with measurements from radiometer arrays, and scaling of spatial statistics with temporal averaging and array size is discussed. Efficient parameterizations for spatial averages and standard deviations of sub-canopy radiation are developed using parameters that can be obtained from the model or hemispherical photography.