Categorising raster data based on shapefile boundaries

Question

I've tried searching for an answer but honestly I'm not even sure how to word my search.

I'm using Arc GIS Pro. I have two layers that I want to analyse.

The first layer is a shapefile and it covers three countries, split up into regions. So, it records the boundaries between those regions. The attribute table has fields for Country and Province.

The second layer is an ESRI grid raster. It contains population info across the study region. I have already clipped it to match the area of the first layer.

I'd like to find the population of each Province from the first layer. So I guess I want a new layer, prov_pop, where the attribute table has: Country, Province, Population. Ultimately, I want to create a map that shows the province boundaries and is colour-graded to population size at a provincial level.

I'm new to GIS and really not sure where to start to produce this.

Answer 1

Please have a look at zonal statistics and zonal statistics as table tools.

Given the objective, you might want to use Zonal Statistics as Table tool. It will generate a table as output (in contrast to the Zonal Statistics which returns a raster as output). Once you get the table, you may simply join it to your input shapefile to get population for each record.

In Zonal Statistics as Table tool, you would use

1. in_zone_data = Your shapefile (The dataset that defines the zones)

2. zone_field = A unique ID or Name Field for Provinces in shapefile (You would later use this field to join the output table with your shapefile)

3. in_value_raster = Population Grid Raster

4. out_table = The output table that will contain the summary of the values in each zone

5. statistics_type = "SUM" (Because you want to calculate sum of all pixels in each particular province to get cumulative population in that province)

Finally, use Add Join tool to permanently join the output table containing (cumulative population) for each province to the shapefile of the province using zone_field you used in step-2.