r.flow - construction of slope curves (flowlines), flowpath lengths, and flowline densities from a raster DEM. SYNOPSIS r.flow . r.flow help r.flow [ -uzmq ] elevin = name [ aspin = name ] [ barin = name ] [ skip = val ] [ bound = val ] [ flout = name ] [ lgout = name ] [ dsout = name ] DESCRIPTION r.flow generates flowlines using a combined raster-vector approach (see Mitasova and Hofierka 1993 and Mitasova et al. 1993)) from an input elevation raster map elevin, and optionally an input aspect raster map aspin and/or an input barrier raster map barin. There are three possible output maps which can be produced in any combination simultaneously: a vector file flout of flowlines, a raster map lgout of flowpath lengths, and a raster map dsout of flowline densities. INSTALLATION Get r.flow.tar.gz from moon.cecer.army.mil using binary transfer. Uncompress and untar using 'gunzip < r.flow.tar.gz | tar -xvf -'. Execute gmake4.1 to create the binary. The included Gmakefile puts the final binary in the directory in which it is ran. Change the 'DIR=' line in the Gmakefile to place the file elsewhere. AUTHORS Original version of program: Maros Zlocha and Jaroslav Hofierka, Comenius University, Bratislava, Slovakia, Modified program (adapted for GRASS): Helena Mitasova and Joshua Caplan, US Army CERL. REFERENCES Mitasova and Hofierka 1993 : Interpolation by Regularized Spline with Tension: II. Application to Terrain Modeling and Surface Geometry Analysis. Mathematical Geology August, 1993 Mitasova, H., Mitas, L., Brown, W.M., Gerdes, D.P., Kosinovsky, I., Baker, T., 1993: Modeling spatially and temporally distributed phenomena: New methods and tools for Open GIS. Proceedings of the II. International Conference on Integration of GIS and Environmental Modeling, Breckenridge, Colorado. Mitasova, H., Hofierka, J., Zlocha, M., Iverson, L.(1993): Modeling topographic potential for erosion and deposition using GIS. submitted to I.J. of GIS in spring 1993. Mitasova, H.(1993): Surfaces and modeling. Grassclippings (winter and spring) p.18-19. *** If you have any problems, questions or comments send an email to helena@gis.uiuc.edu or ruesink@gis.uiuc.edu