Change Detection in GIS: Automated Python Script
- Andy Bohnhoff
- Apr 7
- 3 min read
In the energy and real estate worlds, monitoring land ownership changes is essential. Without effective tracking, organizations risk losing critical insights that can influence major decisions. Recently at Platte River Analytics, we were presented with a problem by a real estate client where land ownership within their AOI was changing hands often and quickly.
So we set out to develop an Python script and Esri dashboard that automates the identification of changes in county parcel data, which in turn enhanced their data analysis capabilities. In this article, we’ll share our journey and the benefits the tools bring to GIS projects.
Understanding the Challenge
Tracking changes in land ownership is complicated and time-consuming. Traditional methods, which often involve manual comparisons of datasets, can lead to errors. For instance, imagine analyzing 20 parcels involved in transactions linked to a new wind farm project. If any changes go unnoticed, the consequence can be considerable, resulting in missed opportunities or misguided investments.
County parcel data is constantly evolving—landowners sell, split, and acquire parcels regularly. But for analysts, tracking these changes manually across hundreds or thousands of records is time-consuming and prone to error. Even subtle changes like a new mailing address or a slight shift in acreage can indicate important updates, such as ownership transfers or parcel splits. Without automation, teams spend hours comparing records line by line, or worse, they miss key changes altogether.
The challenge we faced was creating a reliable system that not only detects these changes swiftly but also presents the information clearly and understandably. Our goal was to improve this situation.
Innovative Solution
To solve this, we built a custom Python script that automatically detects changes in parcel data. The script can be run daily, weekly, or monthly and flags parcels with differences in:
Landowner names: Recognizing when a parcel changes hands.
Mailing address updates: Ensuring correct communication with the current owners.
Parcel size alterations: Noting any splits or expansions in ownership.
If any changes are detected regarding parcel size, such as a split resulting in multiple new plots, the script flags these alterations immediately.
Users have the flexibility to run the script as needed, whether that's daily, weekly, or monthly. This means GIS analysts can stay informed about changes without being overwhelmed by data, resulting in a more streamlined workflow.
To enhance the interactive capabilities, we also developed an interactive Esri dashboard that provides real-time summaries.
Once changes are detected, they’re visualized in an interactive dashboard we built for our clients. The dashboard includes:
A top-left indicator showing how many parcels have changed in the selected time period
A detailed change list showing each updated parcel with key attributes
A map view with changed parcels highlighted for fast visual analysis
An attribute table beneath the map for filtering and sorting
This makes it incredibly easy to scan for changes and drill into the details—no more spreadsheet flipping or manual comparisons.
Real-World Applications in Energy Projects
While this tool is useful for general land monitoring, it's especially powerful in the energy sector. Here are some specific examples:
Oil & Gas: Use it with a layer of mineral units to track newly assigned operators or with a permits layer to visualize new permits taken in specific areas.
Solar Development: Detect when new parcels have changed hands, indicating a possible new project site.
Wind Energy: Monitor parcels or new wind turbines near your developments for early indicators of new activity.
In each of these scenarios, the script acts as a vital tool for organizations to make informed decisions, ensuring they respond effectively to changing landscapes and market conditions.
Looking Forward
Our work doesn’t end with this script. One of our upcoming goals is to integrate the script with Microsoft Power Automate. This upgrade will facilitate automated email notifications for stakeholders, delivering real-time updates on parcel changes without requiring additional manual work.
Ultimately, our aim is to simplify the process of tracking changes in parcel data. With automation, GIS analysts can focus on interpreting insights rather than spending time wading through data. Currently, projects can take weeks to summarize parcel changes; our solution aims to shorten that time to days or even hours.
Wrapping Up
We’re currently working on integrating this script with Microsoft Power Automate. The goal is to send automated alerts via email when parcel changes are detected—right to your team’s inbox. That means no need to even open the dashboard unless something’s changed.
Ultimately, this project reflects our broader mission at Platte River Analytics: to automate data workflows and surface insights before you even know you need them.
If you're interested in learning how this tool can be adapted to your data or workflow, reach out. We'd love to show you a demo and talk use cases. To see a working version of this dashboard, please click this LINK.
Comments