Sometimes we find an old paper map or even a digital map which has important data on it, but after scanning it we cannot load it directly into QGIS, if we do not tell QGIS what the coordinate system is. For this we must go through a process called Georeferencing, which is the topic of this video.
In this video we will georeference a scanned map of the Salma Dam in the Harirud-Murghab River basin of Afghanistan using a satellite image. The map was downloaded from a 2019 WAPCOS tender: http://www.wapcos.gov.in/hindi/uf/DownloadHindi.aspx?udi=12520&folderName=Tenders (last accessed 20/04/2021).
Link to tender docs on Google Drive: https://bit.ly/32xQmeB
Link to Map & Ground Control Points (GCP) on Google Drive: https://bit.ly/3x9pekg
00:00 Introduction
01:45 Step 1: Understand the map coordinates
03:27 Step 2: Decide on grid or object georeferencing
03:42 Step 3: Start the Georeferencer
04:29 Step 4: Add Ground Control Points (GPC)
08:19 Step 5: Chose transformation parameters
10:53 Step 6: Check the results
12:12 Step 7: Print the map
This video is part of the online QGIS 101 training course.
For more QGIS videos see the QGIS playlist: https://youtube.com/playlist?list=PLp1lK6n-xb5Pqm6JmiwORjm8vuK5g2yf1
#QGIS #Georeferencing #Georeferencer