Hi Hugh, how's it going?  Me, I'm in dissertation
land, step by step towards the goal.  I've had a
few interviews: Texas Tech, Univ. of AK-southeast,
Sacramento State.  No luck yet, I'm down to Sac.
State as the final stick in the job fire for this
round.  I consider it a moral victory to make the
top 3 out of 40-50, considering that I'm ABD. 
Given the interest so far, I'm hopeful for the
long term prospects (i.e. with degree in hand and
a couple additional pubs. in the can).  As I'm
sure you know, this has been an emotional and 
physical distraction.

Below is a message that I sent to s. kite, and
likewise am forwarding to you for comment.  Any
help or ideas will be appreciated...

---------------------------

hi s., some ideas to bounce off you for comment    
                            
goal: to make some simple calculations of peak Q
that would be required to move average gravel
clasts from 1st order hollows in each of the 3     
study areas (based on clast diameter / shape),
then convert the peak Q to rainfall intensities
required as a way of normalizing drainage
areas for each site.  The rainfall intensities
will then be compared to known historic records /
estimates (e.g. 1949, Hurricane Camille, etc.)    
to see if the values are plausible.  Anomalously
high values will be used to argue that debris
slide / flow is the primary transport mechanism,
plausible values within known historic range will
be used to argue that normal stream flow /
traction is the primary transport mechanism...
this is out of Hugh's play book (Mills, 1989)      
                            
Now for the question: Hugh measured the intermed.
axis diameters of the 5 largest clasts and
averaged them, then plugged data into Costa (1983)
regression equations for vel and depth required to 
move those clasts (eq. 10 and 19). Then determined
channel slope and hollow profile: vel + depth +
slope + profile = Q critical required to move the
boulders of given average diameter (future
flood discharge estimate rather than paleoflood
discharge estimate)

Q critical is then converted to rainfall intensity
using Dunne and Leopold equation I=Qp/CA  where I
= intensity, Qp = peak Q, C = runoff coefficient,
A = drainage basin area (hugh used a C =
0.9 since dealing with very high hypothetical
intensities, near-surface saturation will likely
be rapid).                                       
                                                   
                            
As we discussed previously in the field, I have
not only clast size issues in this regard, but
also clast shape issues (e.g. flaggy/disk @
Fernow, Equant @ L. River).  Costa's (1983)
theoretical method 1 "Helley (1969)" deals with
clast shape issues using short, int. and long  
axis diameters in the velocity estimates... seems
like this would be preferable to Costa's final
regression equation.                             
                                                   
                            
Have you played with Costa "theoretical method 1"? 
                            

If you have played with method 1, I'm having
trouble reproducing Costa's data and wondering if
there are typos / errors in the published         
equations... have you run into this previously?    
                            
do you have other ideas that I should know about?  
                            
Do you see major problems with this analysis
(before I could through            
the effort, which will be moderately time
consuming)? 

I haven't had a chance to dig up Helly (1969) yet,
but will do so as soon as I'm in striking distance
of the library.                        
                            
I will also contact hugh about this.


Thanks, s.t.                                       
