Zonal statistics for raster using a matching mask file

MorganHarris

Hi again GeoNet community!

 

I have a question and the answer may involve script. Just a warning, I have very rarely dealt with scripting and so if the answer is a script code then I may need some extra guidance. Anyway, my problem is this:

 

I have about 1300 raster layers that I need to iterate through. For each raster layer, I need to run zonal statistics using a polygon layer. Each polygon layer corresponds to each raster in space and they also have the same file name (i.e. the raster name is 110_10R and the polygon file name is 110_10R as well, they are just saved in different folders. How can I make it so that 110_10R (raster) uses 110_10R (polygon) for its zonal statistics? Remember this needs to iterate 1300 times (actually 1300 x 12) so it needs to be 110_10R (raster) with 110_10R (polygon) then it moves on a runs 111_10R (raster) with 111_10R (polygon)...etc...

 

Remember, scripting novice, but I realize that it may be the only way to solve this issue

 

Thanks!

JakeSkinner

Something like below should get you started:

import arcpy, os
from arcpy import env
from arcpy.sa import *

rasterWorkspace = r"C:\Users\AmyShipley\Desktop\Offline_2014_GIS\Exposure_Height"
polygonWorkspace = r"C:\Users\AmyShipley\Desktop\Offline_2014_GIS\shp_files\Distance_Buffers"

env.workspace = polygonWorkspace
shapefiles = arcpy.ListFeatureClasses("*", "Polygon")

env.workspace = rasterWorkspace
rasters = arcpy.ListRasters("*", "TIF")

for shapefile in shapefiles:
    shapefileName = shapefile.split(".")[0]
    for raster in rasters:
        rasterName = raster.split(".")[0]
        if rasterName == shapefileName:
            outZonalStats = ZonalStatistics(shapefileName, "value", rasterName, "SUM", "DATA")
            outZonalStats.save("zoneStats_" + shapefileName)

The above code will iterate through the raster workspace and find all TIFF files.  If you are working with a different raster type, take a look at the ListRasters to change to the correct type, or simply remove "TIF" to use all rasters.