Network Analysis in QGIS

hello so this tutorial is to show how to make network analysis using QGIS so what you actually need is line network and some points layers the two that we're gonna use is here if you go to the processing toolbox to access the processing toolbox it's not here just go to view panels processing toolbox and then you see here under the network analysis there's a tool box called service area from layer so if you double click here you can see that you input an existing line network and effect earlier which starts point so what is algorithm does is that it calculates it outputs a line layer with within the network that you've inputted here with with a given travel cost it means like this could be either in distance or in time so you choose shortest for distance or fastest for time so for example I'm gonna need a point layer so I'm gonna make a temporary point layer here I'm gonna call this origins of the service area and I'm gonna add some points they don't have to be on the network they can be just close so service area from layer I'll choose the network streets layer here origins shortage and on the trello cost I'm gonna put 400 that's 400 and years not sure if this is gonna work they are on different coordinate systems but let's write yeah it so apparently worked so this output here and see I've I've inputted the layer on origins layer with powerpoints so it should have four different features here yet so each one of this feature is one a network buffer here and click one so that's probably the buffer from this point so the output is like a align layer but that's only one geometry right so what we can do with this also is to find a polygon that encloses this network so for example if you want to make a spatial join about something that's in here inside the network buffer so I'm gonna try to create a Kincaid home here to create an closing geometry on polygon within each one of these for Network purpose here so I'm gonna choose the concave whole thing nearest neighbor and on the field I'm gonna say start because each one of these has a different starting point and I want to the algorithm generate different a different polygons for each one of the network so service area field start so that's it you can choose the parameter to see how enclosing these polygons is fits more like a circle or if it's more like an irregular shape I'm gonna just decrease the opacity here so we can see the layers overlap yep that's it okay that's it thank you

Channel: Nicholas

Views: 6,938

Rating: 4.9512196 out of 5

Keywords: QGIS, network analysis, GIS, geospatial analysis

Id: WzT9_jMbBDw

Length: 4min 42sec (282 seconds)

Published: Sat Jan 25 2020