Terry's GIS Studies and Transition to a New Career

Thursday, February 27, 2020

Criteria 2--Homes and Parcels

For criteria 2, I quantified the number of homes and parcels impacted by the transmission line. I relied heavily on the U.S. Census Bureau TIGER files and imported edges and addresses. I also downloaded data from the Sarasota and Manatee Counties Assessors' Offices to obtain updated information.

I obtained my data in two ways. First, I conducted a heads up count where I methodically counted the number of parcels inside the corridor (yellow) or within the 400ft buffer (orange). I then utilized the TIGER files (and compared it with the assessors' files), created an intersection with the buffer and then the corridor, and determined the number of houses and parcels.

The amount of houses and parcels were nowhere near the result from my heads up count. I decided to use my heads up count for my analysis for a number of reasons:  The imagery was much older than the assessors' files and the Census data was close to 10 years old, what constituted a parcel was not known, and there were many structures on the map that might have been houses, garages, barns, sheds, etc. Additionally, in some of the more wooded areas, it was impossible to see structures due to the trees and shadows.

One of the important lessons learned for all maps produced was to make sure all layers had the same geographic reference system and projection. Additionally, the units of measure were required to be imperial, so any metric unit had to be converted to feet, miles, etc.

Homes and parcels within the study area. The inset map shows the full corridor in a smaller scale
in order to orient the viewers. The symbols are consistent with regard to type and color. I have also
included a comparison between the heads up counts and the assessor counts.



No comments:

Post a Comment