calculation of LAI for flexible vegetation

[VeroM96]

In the current schism version, the leaf area index (LAI) is treated as a parameter. However, the definition of LAI is leaf area relative to the ground area. For seagrasses, this could easily be calculated by multiplying canopy height x leaf width (maybe use the diameter) x shoot density x leaves per shoot and would be an easy fix in schism_step.F90, adding the leaves per shoot as parameter in param.nml.

For other kinds of vegetation, the calculation of the LAI might be more difficult. But maybe since the formulation by Ganthy (2011) for the flexible vegetation is also based on seagrass, calculating the LAI as described above could be a reasonable fix for now.

[josephzhang8]

Thx @VeroM96. I'm reviewing some more recent papers and will revise this option (which is under active dev as you have noticed). Some papers have pointed out the drawbacks of this LAI approach and replaced it with a simpler approach using free streaming vel.