Latvia Grass 6.4.1 Experiment using Elevation Files

The map below was produced using GRASS 6.4.1 in which I added shapefiles for Latvian elevation and railroads.  These shapefiles are on the web.  The thin lines are Latvian railway lines.  In this first attemp, I tried to use the hydrology program to "carve channels" using the railroad vector file as the source of the streams.  So far, I was not able to get a positive result.  Is it possible that Latvian railways are all on the surface or embankment?  If time permits, I will experiement later,  In working with data from a country or location which is different from your source maps, it is important to first bring in your first file, shape or otherwise to a blank map, and then use the "o" option to set the projection to the area where the map is.  Even though this map is in my New York directory, by bringing in the first file from Latvia, and setting the code to option "O", my coordinates are now for Latvia.  More to follow later.