计算坡度与坡向
#!/usr/bin/env python # -*- coding: utf-8 -*- import subprocess # SLOPE # - To generate a slope map from any GDAL-supported elevation raster : # gdaldem slope input_dem output_slope_map" # [-p use percent slope (default=degrees)] [-s scale* (default=1)] # [-alg ZevenbergenThorne] # [-compute_edges] [-b Band (default=1)] [-of format] [-co "NAME=VALUE"]* [-q] create_slope = '''gdaldem slope -co compress=lzw -p ../geodata/092j02_0200_demw.dem ../geodata/slope.tif ''' subprocess.call(create_slope) # ASPECT # - To generate an aspect map from any GDAL-supported elevation raster # Outputs a 32-bit float raster with pixel values from 0-360 indicating azimuth : # gdaldem aspect input_dem output_aspect_map" # [-trigonometric] [-zero_for_flat] # [-alg ZevenbergenThorne] # [-compute_edges] [-b Band (default=1)] [-of format] [-co "NAME=VALUE"]* [-q] create_aspect = '''gdaldem aspect -co compress=lzw ../geodata/092j02_0200_demw.dem ../geodata/aspect.tif ''' subprocess.call(create_aspect)
计算山体阴影
#!/usr/bin/env python # -*- coding: utf-8 -*- import subprocess dem_file = '../geodata/092j02_0200_demw.dem' hillshade_relief = '../geodata/hillshade.tif' relief = '../geodata/relief.tif' final_color_relief = '../geodata/final_color_relief.tif' create_hillshade = 'gdaldem hillshade -co compress=lzw -compute_edges ' + dem_file + ' ' + hillshade_relief subprocess.call(create_hillshade, shell=True) print create_hillshade cr = 'gdaldem color-relief -co compress=lzw ' + dem_file + ' ramp.txt ' + relief subprocess.call(cr) print cr merge = 'python hsv_merge.py ' + relief + ' ' + hillshade_relief + ' ' + final_color_relief subprocess.call(merge) print merge create_slope = '''gdaldem slope -co compress=lzw ../geodata/092j02_0200_demw.dem ../geodata/slope_w-degrees.tif ''' subprocess.call(create_slope) # gdaldem hillshade -co compress=lzw -compute_edges -az 315 -alt 60 -z 2 in_relief.asc 315.tif # gdaldem hillshade -co compress=lzw -compute_edges -az 275 -alt 60 -z 2 in_relief.asc 275.tif # gdaldem hillshade -co compress=lzw -compute_edges -az 355 -alt 60 -z 2 in_relief.asc 355.tif # gdaldem hillshade -co compress=lzw -compute_edges -az 135 -alt 60 -z 2 in_relief.asc 135.tif # gdaldem slope -co compress=lzw in_relief.asc slope.tif # gdaldem color-relief -co compress=lzw slope.tif rampslope.txt slope_col.tif # gdaldem color-relief -co compress=lzw in_relief.asc ramp.txt relief_col.tif