Methodology from basic Basic Level for the whole process. I need a list of zip codes. This is the map: https://eligibility.sc.egov.usda.gov/eligibility/welcomeAction.do?pageAction=sfp If we drill in, we can see on the map that some areas are shaded and some are not. I would like to now any zip code that touches unshaded areas and any zipcode that touches shaded areas. I want a list for all the biege areas and then a list for all non-beige areas. Any helping material or tutorial.
The MapServer that underlies and feeds that map is located here, which can be found by opening the developer tools of your web browser and looking for network assets associated with the web map.
The specific layer you desire is called RHS SFH MFH (ID: 4). You can directly query that layer and get a spatial data format like geoJSON here. Just supply a list of
xmin,ymin,xmax,ymax in the input geometry field and choose a geometry type of Envelope. I would suggest being broad and using the whole northwestern quadrant:
-180,0,0,90. Be sure to supply
4326 in the input spatial reference field, since these are geographic coordinates. Then select geojson as the format at the bottom of the page and GET the request.
Once all the data loads, save the page (it should be around 14MB) as a .geojson file.
The best approximation of zip code geometry you will likely be able to get is the US Census' Zip Code Tabulation Areas. With these two datasets, you should be able to do a spatial analysis with your application of choice and yield the two lists you desire.