QGIS Basics #2: Create Scratch Polygon Layer and Adding Polygons

[@dusanopacic1900]

excellent tutorial Hal, clear, accurate and concise. I am stunned, really! cheers!

[@sidharthkumarrout9335]

Thank you

[@mmk3827]

From India 🇮🇳 ♥️

[@ChrisSmithFW]

Thanks, Hal. Trying to determine how to create polygons from legal descriptions of tracts of land. Do you have a tutorial for this? Any good books you recommend for a newbie who's very technical but not in QGIS yet?

[@adanesh]

Nice. but the background music is distracting a bit

[@HalHartQGIS]

Thats why I Did a no music playlist as well. LOL😁

[@Dashing123]

thank u sir

[@mther123]

Great brother

[@ProfBoggs]

This is a very clear tutorial. I've never thought of two polygons overlapping like your Star of David shape. Usually when I think of polygons in a GIS, I imagine them as containers that correspond to some administrative boundary (e.g., provinces, states, countries, counties, electoral districts) and that fill out the entire territory. Do have real-world examples of when you might see two polygons overlapping (if they are in the same layer)? I can imagine seeing two polygons overlapping so long as each is in a different layer. But now I'm curious!

[@HalHartQGIS]

Usually overlapping will happen if two polygons inhabit the same space but have different data that is unique to the polygons respectively. You can actually use the intersecting or overlapping parts to form a new section and join the parts that over lap. Many times overlapping will be caused by coordinate collection at different time periods. If you were to track regions where whales traveled from year to year eventually you will get some over lapping of those features. When you do, you can compare that data and choose to separate that area into a new feature, run calculations on how many times the action has recurred, or change the visualization for how that portion of that feature or the map will look in comparison with its neighbors.

[@ProfBoggs]

@@HalHartQGIS Thank you, that example helps me wrap my head around it.

[@alessandroradice6519]

Hi thanks for explanation! How to scale a shapefile? (I imported a dwf from autocad but it is too big)

[@salmazahra4523]

Hey, how can i make a polygon on QGIS from excel data? I have the location data and number of vertices in an excel file.

[@salmazahra4523]

Thanks, that’ll be awesome!

[@indra5131]

How can I erase what I did?

[@HalHartQGIS]

Right click on layer and press remove layer to remove layer and can then redo it. If you want to just undo with in canvas there is an arrow symbol in the digitizing toolbar with undo and redo function. That is only for canvas though. If you have anymore problems let me know.