I am still investigating the outputs of various simulations I ran, and may eventually answer my own question. However, I am hoping someone with experience using this module can provide some insight or guidance.
First off, the r.sim.water is very cool! Especially an animation sequence of walkers I saw in a document online by Helena Mitasova (http://www.ing.unitn.it/~grass/conferences/GRASS2002/proceedings/proceedings/pdfs/Mitasova_Helena_2.pdf ) that referenced this gif animation: (http://skagit.meas.ncsu.edu/%7Ejaroslav/centennial/anim/walkers.gif)
However, under various simulations I am getting no walker output for some time steps through the simulation. Also, if the simulation is not time-stepped no walkers are outputted. Using v.info I am getting one point for walker output. If I step through the simulation 10 times, I get walker output on the 1st step, the 9th and 10th step, and only one walker point for all the other steps. In other simulations that had 8 steps, I might have gotten walker output for 2 of the 8 steps.
I am still tuning the input parameters and checking results. If anyone has some suggestions relating to this issue I would greatly appreciate it!
Thanks,
Mark