SLOPE TOOLKIT (slope.tar) 10/10/97 ================================== PURPOSE: ======== The slope toolkit is used to create a raw slope grid and/or a reclassified slope range grid from an existing elevation grid. The tool also allows plotting of the slope grids. USAGE: ====== 1. First, unpack the toolkit: tar -xvf slope.tar 2. Copy or move the file(s) "slope_per.remap" (for PERCENT slope) and/or "slope_deg.remap" (for DEGREE slope) into the workspace where processing will occur. Edit the file(s) to include the appropriate absolute-values- to-slope-ranges remapping schema (see notes below for more details). The name(s) of the remap file(s) can be changed ONLY IF you plan to use slope_range.aml to create a slope-range grid (see below). If you plan to use slope.aml to create slope ranges, then the remap file(s) must retain the original name(s). 3a. To create both raw (absolute values) and reclassified (ranges) slope grids all at once: Arc: &r slope -- run without arguments to see usage (NOTE: this AML requires either slope_per.remap or slope_deg.remap files to exist) OR... 3b. To separate the raw-slope-grid creation process from that of the slope-range-grid process: Arc: &r slope_raw -- run without arguments to see usage (NOTE: this AML only creates the raw slope grid; no remapping into ranges is performed) &r slope_range -- uses output of slope_raw.aml to create ranges grid (NOTE: this AML allows the remap file to have any name, and only creates the raw slope grid) 4. If you want to create a plotfile of the slope ranges, copy the file "slope.clr" into the workspace. Edit to assign RGB color values to the slope ranges used in the *.remap file in the previous steps. This color file can be renamed without restrictions, and will be used as an argument in the next step. 5. To create a plotfile: &r slope_plot -- run without arguments to see usage (NOTE: Refer to the AML program headers for more detailed information) TOOLKIT FILES: ============== The following are an integral part of the slope toolkit: slope.aml - Takes an existing elevation grid (eg. one that was already created by DEMLATTICE or dem2grid.aml), and uses the appropriate remap file (explained below) to SLICE the grid into the chosen slope ranges. slope_raw.aml - Is essentially the first part of slope.aml - creates a raw-slope grid (real values for each cell) from an existing elevation grid. slope_range.aml - Is essentially the second part of slope.aml - creates a grid of slope ranges by SLICE-ing the raw values into integer ranges via a user-defined remap file. slope_plot.aml - Uses a colorfile to make a plot file of the slope grid. slope_deg.remap - ASCII file of the ranges of absolute slope values and their corresponding remapped range values for output reclassified slope grid, used by Grid:SLICE function. Values are for degree slope. slope_per.remap - Same, except values are percent slope slope.clr - ASCII color map file for use by ArcPlot:GRIDPAINT command in slope_plot.aml, also used for screen display. Included in the .tar file are these other useful programs: dem2grid.aml - converts DEM file to ARC elevation grid. Options exist for resampling, INT/FLOAT, FT/METERS, Yshift. gridmosaic.aml - mosaics multiple adjoining grids together. neatline.aml - creates a geometrically correct neatline coverage for use in clipping to the proper extent. OUTPUTS: ======== The outputs of this slope toolkit are (if all options are chosen): 1. ARC/INFO raw slope grid from input elevation grid. 2. ARC/INFO reclassified slope range grid with raw values remapped into user-defined ranges. 3. Optional ARC/INFO graphics plotfile of slope ranges, with any user-created vector data overlaid on the slope colors (user must have previously obtained and prepared any vector data for overlay). EXAMPLES OF REMAP AND COLOR FILES: ================================== These example files show slope values grouped into 5 arbitrary ranges. The user can define any number of output ranges. Comment lines begin with "#". 1. "slope_per.remap" (used by slope.aml or slope_range.aml): # Remap table for percent-slope grids # Format is input_cellvalue_range : output value # Output values are then used to plot grids using the "slope.clr" file # These slope ranges were arbitrarily chosen using degree-slope values # These %slope values were calculated from the degree-slope values using: # percent_slope = TRUNCATE [(tan (degree_slope)) x 100] # Conversely, degree_slope = arctan (percent_slope / 100) 0 3 : 1 4 15 : 2 16 44 : 3 45 100 : 4 101 100000 : 5 2. "slope_deg.remap" (used by slope.aml or slope_range.aml): # Remap table for degree-slope grids # Format is input_cellvalue_range : output value # Output values are then used to display grids using the "slope.clr" file # These slope ranges were arbitrarily chosen # Degree-slope values can be calculated from percent-slope values using: # degree_slope = arctan (percent_slope / 100) # Conversely, percent_slope = (tan (degree_slope)) x 100 0 2 : 1 3 9 : 2 10 24 : 3 25 45 : 4 46 90 : 5 3. slope color file "slope.clr" (used by slope_plot.aml, usually contains a ".clr" suffix, but can have any name): # Slope color file, broken into 5 ranges (gray, blue, green, yellow, red) # Columns are: Gridcell value, Red, Green, Blue # Cellvalues were remapped using "slope_deg.remap", "slope_per.remap" files 0 255 255 255 1 200 200 200 # gray 2 25 25 250 # blue 3 25 250 25 # green 4 250 250 25 # yellow 5 250 25 25 # red John Kosovich (303) 202-4301 jjkosovich@usgs.gov