[GRASS-user] segment_format error with r.watershed

[Wes Kent]

Greetings all,

I am trying to run r.watershed on a county-wide LIDAR data layer.  
However, r.watershed returned a segment_format error during Section 1 of 
the analysis.  Here is the error output:

SECTION 1 beginning: Initiating Variables. 5 sections total.

segment_format(fd,1,-1831011296,1,25,20): illegal value(s)

seg_open(): illegal configuration parameter(s)


Also, for reference, here is the information for the elevation input map 
being used:


Type of Map:  raster               Number of Categories: 255            
 |   Data Type:    
FCELL                                                     
 |   Rows:         
44000                                                     
 |   Columns:      
55999                                                     
 |   Total Cells:  
-1831011296                                               
 |        Projection: State 
Plane                                            
 |            N: 589970.67755842    S: 479971.19725012   Res: 
2.49998819     
 |            E: 2226464.7485208    W: 2086468.7440966   Res: 
2.49997329     
 |   Range of data:    min = 764.770020  max = 
1324.199951                   
 |                                                                            

 |   Data 
Description:                                                       
 |    generated by r.patch                                                 


The raster layer consists of about 530 separate grids that were patched 
together in stages using r.patch.  The resolution of the layer is 2.50 feet.

I am not able to determine what would have caused the error.  Are there 
too many rows/columns, or is the negative value for the "Total Cells" 
causing a problem?  Perhaps I used the wrong approach in patching the 
individual grids together?

If any additional information is needed, let me know, and I will do my 
best to provide it.  Many thanks for any and all assistance.


~Wes