Rapid determination of canyon geometry parameters for use in surface radiation budgets

The parameterisation of canyon geometry as a sky-view factor is common prac tice when studying surface radiation budgets. However, the accurate computa tion of sky-view factors can prove to be slow and has often resulted in stu dies involving the sky-view factor to be limited to just a few study sites. A fully automated digital approach to calculating sky-view factors direct from digital imagery is presented along with a simple methodology to determ ine the impact of surface geometry on the nature of incoming shortwave radi ation. The validity of these new automated techniques is tested by a compar ative study with alternative methodologies, producing nearly identical resu lts. It is hoped that the rapidity of the techniques should allow for the i mpacts of canyon geometry on surface radiation budgets to be studied on a s cale not previously possible.