GIS and Boundary Lines
Posted: Sun May 06, 2012 6:36 am
If any of us in the land surveying profession think our profession isn't in danger of becoming obsolete, consider this post from another surveyor's forum.
Conversion of the Digital Parcel GIS Map to Survey Grade Accuracy:
My Ph.D. research at the University of Florida since 2003 shows that today almost all counties (parishes) in the United States and in many other countries now own and maintain public Digital Parcel GIS Maps (“Parcel GIS Mapâ€) which were usually created from the hand-drawn tax maps and other recorded information. Additionally, most jurisdictions also have a relatively current, high accuracy, digital, aerial orthophoto mosaic which can be viewed on the internet as an overlay on its Parcel GIS Map.
Many of these Parcel GIS Maps are now in the process of being rectified by ground data such that the corners and lines more closely agree with the aerial orthophoto mosaics and “ground truth.†Once rectified, these Parcel GIS Maps can produce state plane coordinates (and/or latitudes and longitudes) sufficient to produce boundary maps for most, if not all, boundary requirements.
Survey grade GPS allows for the use of this coordinate information to locate corners and lines on the ground. As this high grade GPS becomes more available to the public it is inevitable that within a short period of time this new technology will cause the traditional boundary surveys by licensed (registered) land surveyors to be unnecessary. Given these indisputable facts my questions are these:
1. Will land surveyors accept, understand and use this new technology?
2. How can land surveyors use this new technology to avoid becoming obsolete?
3. Is it too late for land surveyors to participate in these conversions?
4. Will the interrelated web of all of the parcels in these Parcel GIS Maps act to reduce litigation over disputed boundaries?
Ted Madson
April 19, 2012
Mr. Madson's response to questions;
Thanks for your good faith question. My comments have been designed to inform our profession that the winds of change are upon us as regards the location of boundaries between landowners. As you point out, the confusion caused by different surveyors using the same information to set different corner monuments is the tip of the iceberg.
Thinking out of the box, consider the Treaty of Guadalupe Hidalgo, the peace treaty largely dictated by the United States to the interim government of a militarily occupied Mexico City, that ended the Mexican-American War (1846 – 48) on February 2, 1848. That Treaty provided that all lands claimed by Mexican Nationals would be honored up to a certain date (the "drop dead" date), after which the United States took over those lands and wrote the descriptions as desired without regard to previous claims.
If this same strategy were to be used with a survey grade GIS a law could be passed that would establish the lines and corners as shown on the GIS to be authoritative as regards boundaries for ownership of lands. This would obviously stop any claims after the drop dead date of that law. This solution is being seriously discusses at this time.
Conversion of the Digital Parcel GIS Map to Survey Grade Accuracy:
My Ph.D. research at the University of Florida since 2003 shows that today almost all counties (parishes) in the United States and in many other countries now own and maintain public Digital Parcel GIS Maps (“Parcel GIS Mapâ€) which were usually created from the hand-drawn tax maps and other recorded information. Additionally, most jurisdictions also have a relatively current, high accuracy, digital, aerial orthophoto mosaic which can be viewed on the internet as an overlay on its Parcel GIS Map.
Many of these Parcel GIS Maps are now in the process of being rectified by ground data such that the corners and lines more closely agree with the aerial orthophoto mosaics and “ground truth.†Once rectified, these Parcel GIS Maps can produce state plane coordinates (and/or latitudes and longitudes) sufficient to produce boundary maps for most, if not all, boundary requirements.
Survey grade GPS allows for the use of this coordinate information to locate corners and lines on the ground. As this high grade GPS becomes more available to the public it is inevitable that within a short period of time this new technology will cause the traditional boundary surveys by licensed (registered) land surveyors to be unnecessary. Given these indisputable facts my questions are these:
1. Will land surveyors accept, understand and use this new technology?
2. How can land surveyors use this new technology to avoid becoming obsolete?
3. Is it too late for land surveyors to participate in these conversions?
4. Will the interrelated web of all of the parcels in these Parcel GIS Maps act to reduce litigation over disputed boundaries?
Ted Madson
April 19, 2012
Mr. Madson's response to questions;
Thanks for your good faith question. My comments have been designed to inform our profession that the winds of change are upon us as regards the location of boundaries between landowners. As you point out, the confusion caused by different surveyors using the same information to set different corner monuments is the tip of the iceberg.
Thinking out of the box, consider the Treaty of Guadalupe Hidalgo, the peace treaty largely dictated by the United States to the interim government of a militarily occupied Mexico City, that ended the Mexican-American War (1846 – 48) on February 2, 1848. That Treaty provided that all lands claimed by Mexican Nationals would be honored up to a certain date (the "drop dead" date), after which the United States took over those lands and wrote the descriptions as desired without regard to previous claims.
If this same strategy were to be used with a survey grade GIS a law could be passed that would establish the lines and corners as shown on the GIS to be authoritative as regards boundaries for ownership of lands. This would obviously stop any claims after the drop dead date of that law. This solution is being seriously discusses at this time.