- Messages
- 1,601
- Country
Hey Arno, here’s an idea for water detection. More of a work-around that may be quicker and prove worthy while true water detection continues development. What I have noticed is a lot of water is placed in the shadows of mountains, hills or steeper slopes. Not always, but maybe a good percentage (80% maybe?).
What if we used DEMs to filter out unwanted water shp polygons based on the percentage of a slope? For example, scenProc removes all water shp files that have <10% slope (user configurable). Not sure if you would need a distance or radius that determines in that area we have a slope that is greater or less than 10% but you get the idea.
So for now we would run TFE for water detection as we are doing now. We now have our water shapefiles, granted with many errors. From there we could create something like the following:
ImportGDAL|B:\CA\Section_64\Images\CA_BV47_DEM.tif|*|NOREPROJ|String;CENTER|elev
ImportOGR|B:\CA\Section_64\Masks Water\CA_BV47_WM.shp|*|*|NOREPROJ
AddAttributeSampleRaster|FROMFILE=”CA_BV47_WM.shp”|FROMFILE=”CA_BV47_DEM.tif”|slope|10
ExportOGR|WatType="water"|ESRI Shapefile|B:\CA\Section_63\Masks Water\CA_BW46_WM.shp|water
Of course I have not thought this through completely, but I am hoping you get the idea what I am thinking from above to create this type of step. I have around 30 days to find a way to get a higher percentage of correct water bodies (Ahhhh!) . Your thoughts in testing this idea in scenProc?
What if we used DEMs to filter out unwanted water shp polygons based on the percentage of a slope? For example, scenProc removes all water shp files that have <10% slope (user configurable). Not sure if you would need a distance or radius that determines in that area we have a slope that is greater or less than 10% but you get the idea.
So for now we would run TFE for water detection as we are doing now. We now have our water shapefiles, granted with many errors. From there we could create something like the following:
ImportGDAL|B:\CA\Section_64\Images\CA_BV47_DEM.tif|*|NOREPROJ|String;CENTER|elev
ImportOGR|B:\CA\Section_64\Masks Water\CA_BV47_WM.shp|*|*|NOREPROJ
AddAttributeSampleRaster|FROMFILE=”CA_BV47_WM.shp”|FROMFILE=”CA_BV47_DEM.tif”|slope|10
ExportOGR|WatType="water"|ESRI Shapefile|B:\CA\Section_63\Masks Water\CA_BW46_WM.shp|water
Of course I have not thought this through completely, but I am hoping you get the idea what I am thinking from above to create this type of step. I have around 30 days to find a way to get a higher percentage of correct water bodies (Ahhhh!) . Your thoughts in testing this idea in scenProc?