Zonal Statistics as Table issue

[DuminduJayasekera]

Hi,

I need to estimate zonal statistics (MEAN) using the "Zonal Statistics as Table" tool in ArcGIS. I have the underlying raster in color (see the image below) and the polygon (grid, TownWilson) in pink color. As you can see, there are 20 grids in the TownWilson grid (shapefile). The grid IDs (T_R) are shown in the table below.

"Zonal Statistics as Table" tool and set up the environment variables as shown below. 

 

The output table and after the Zonal Statistics as Table run is complete is as follows. It shows zonal mean statistics for ONLY 12 grid IDs (T_R) out of 20 grid IDs in the original TownWilson table above. 

Can somebody help me to obtain the statistics for all the T_R IDs in the grid? I cant understand what I am doing wrong here.

Thanks in advance for help.

[DuminduJayasekera]

Dan,

Please see my code complete code below which extract variable from netCDf file, project and save as .tif file. 

import arcpy, sys 
from arcpy import env 
from arcpy.sa import * 
import time
 
# Input data source 
arcpy.env.workspace = r"C:/Users/Desktop/weekly_avg_project" 
arcpy.env.overwriteOutput = True 
 
# Set output folder 
OutputFolder = r"C:/Users/Desktop/weekly_avg_project/output" 
 
# Loop through a list of files in the workspace 
NCfiles = arcpy.ListFiles("*.nc") 
start = time.time()‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

NCfiles = arcpy.ListFiles("*.nc") 
start = time.time()
for filename in NCfiles: 
 print("Processing: " + filename) 
 inNCfiles = arcpy.env.workspace + "//" + filename 
 fileroot = filename[0:(len(filename)-3)] + '_var86' 
 TempLayerFile = "SM_amount" 
 outRaster = OutputFolder + "//" + fileroot 
 # Process: Make NetCDF Raster Layer 
 outfile = arcpy.MakeNetCDFRasterLayer_md(filename, "var86", "lon", "lat", TempLayerFile, "", "", "BY_VALUE") 
 proj_ras = arcpy.ProjectRaster_management(outfile, "C:/Users/Desktop/weekly_avg_project/project_ras","PROJCS['USA_Contiguous_Albers_Equal_Area_Conic',GEOGCS['GCS_North_American_1983',DATUM['D_North_American_1983',SPHEROID['GRS_1980',6378137.0,298.257222101]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]],PROJECTION['Albers'],PARAMETER['False_Easting',0.0],PARAMETER['False_Northing',0.0],PARAMETER['Central_Meridian',-96.0],PARAMETER['Standard_Parallel_1',29.5],PARAMETER['Standard_Parallel_2',45.5],PARAMETER['Latitude_Of_Origin',37.5],UNIT['Meter',1.0]]", "BILINEAR", "10 10", "NAD_1983_To_WGS_1984_1", "", "GEOGCS['GCS_WGS_1984',DATUM['D_WGS_1984',SPHEROID['WGS_1984',6378137.0,298.257223563]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]]")
 # Process: Copy Raster 
 arcpy.CopyRaster_management(proj_ras, outRaster + ".tif", "", "", "", "NONE", "NONE", "")‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

[DuminduJayasekera]

Dan and Xander,

Thanks for both of you for the help provided throughout. I figured that out and its working now. I have tested few rasters manually. 

[DuminduJayasekera]

Thanks Dan. Do you suggest me to re-sample the raster for 10m resolution (as Xander finds out) before perform the zonal statistics.?

[DanPatterson_Retired]

Resample .... to resample raster or even Copy Raster, but you would need to specify the cell size, extent and snap raster in the Environments tab of that tool

[DuminduJayasekera]

I will try this. Any suggestion of what re-sampling technique I should use. Nearest/Bilinear/Cubic? The raster data has soil moisture. 

[DanPatterson_Retired]

the help provides some guidance, but I wouldn't go with 'nearest' since it is generally for categorical data