I am using my county's GIS data to update the roads in OpenStreetMap. I have a copy they published last year and one that was just published, and I would like to find all the LineStrings that have either had their attributes or their geometry changed. This will assist me in making sure all the new and modified streets are updated in OpenStreetMap.
The street segments should have a unique identifier, so my only thought is to write a Python script which opens both Shapefiles, finds any segments in the new that aren't present in the old (added segments), and the reverse (removed segments), and then loop over matched pairs comparing their constituent coordinates to see if anything has changed.
Is there a way to do this using QGIS?
Best Answer
The thing you need to do is a temporal analysis. As you said you have two vector data(shp) of different times. you can find the change using geometry processing. In QGIS load two vectors and GoTo Vector->GeoProcessing and from there you can use Difference function which will give another shape as a result.