Hi Balaji and George,
My supervisor encouraged me to find a more catchy name, so I've come up
with FERGI.

LEB.cpp is a very simple hydrologic model, but it is more analysis than is
currently being applied in post-fire hydrology.  The primary complexity
right now is turning the WEPP-based output into pulses of precipitation.  I
would rather read in the resampled and rescaled pulse data from the climate
generator directly.  That is a bit longer of a project, so will wait until
the rest of it is generally assembled.

Right now the program just does the hydrology and estimates peak 15 minute
runoff rates and durations.  In a spreadsheet (lebannual.xls), I took that
information and applied Woolhiser's (1975) steady rainfall excess kinematic
wave model (a very simple method of characteristic solution) to estimate
the the maximum distance downslope that the upslope boundary condition
propogates during the duration of the runoff, which gives the peak runoff
rate on the hillslope.  That information can be turned into "flow depths"
using an estimate of roughness (in this case from the median particle
diameter of the soil), which can be used to estimate where on the hillslope
the critical shear stress for movement is exceeded.  Based on Erkan
Istanbulluoglu's work this would be a good estimate of the temporary
dynamic channel head would occur.  Without knowing the sources of the
equations, the spreadsheet would be hard to follow, as I did some of the
calculations separately.  If Adam or any of you are very interested, I
could walk you through it quickly.  All of the complexities of two
dimensional flow routing, such as the models developed by Garry Willgoose
and another by Fritz Fiedler are not dealt with at all at this stage.
There would be benefit in considering more complex routing at a later date
because the logs do move water laterally.  The agency is not very patient
for models right now and seems willing to use poorer models, so I figure
that if I want to get funding to make improvements later, I need to produce
something imperfect now.

When I get all of the spreadsheet calculations programmed into LEB, I will
send a new version.  It is easy to do, but I just need the uninterrupted
time to do it.

Any feedback and suggestions would be appreciated.

Best Regards,
Charlie



(See attached file: LEBparam.dat)(See attached file: arrowrock01.cli)(See
attached file: LEB.cpp)


(See attached file: FERGI description.doc)(See attached file:
lebannual.xls)
__________________________________________________
Charlie Luce
Research Hydrologist
USDA Forest Service
316 E. Myrtle St. Boise, ID  83702
(208) 373-4382
cluce@fs.fed.us
http://www.fs.fed.us/rm/boise/
__________________________________________________