I am using a raster of land cover (Globcover 2.2, 300 m resolution), which I managed to reclassify (in 2 land cover categories) and clip to my region of interest. I also have a shapefile of the roads within this region of interest. I am interest in areas within 1 km from each side of the road, so I created a buffer of the road layer. I would like a way to combine (or merge, not sure about the terminology) these two so I have a new raster that has the 2 land cover classes and a third class equivalent to the roads. How can I do this?
The Spatial Analyst tool
Map Algebra can be used to apply a "conditional" on whether a land-cover cell is within the road buffer area, or not.
I recommend first using
Polygon to Raster to create a raster from the road buffer. Be sure to give a consistent cell-size and raster type (integer, preferred for performance.) This will give a black-and-white raster where value 1 is inside the buffer and value 0 is outside.
Next use Map Algebra to compute a new raster which equates to
CON(road_buffer_raster, 0, land_cover_raster, road_buffer_raster)
This reads as: If the raster cell is outside the road_buffer_raster, then return the land_cover_raster value, if the cell is inside the road_buffer_raster, then return the value of the road_buffer-raster.