Hey I am a first time user of GIS and I am working for a transportation map of North Carolina for a project at my work. So what I have been doing is first placing the Tiger County Boundary by using the add vector layer tool and selecting the directory setting and then select tiger. I then do the same thing for a layer that contains all of the roads. They do not line up and the road layer is significantly larger than the county boundaries. I tried to mess with the CRS, but it did not seem to change anything. I am just taking a guess, but I am assuming that it is a scaling issue? Anyway please help

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    The problem is (probably) related to the projection that the original data is in. Data will scale automatically if both your layers are in the same projection, but if one's in UTM and one's in State Plane (just as an example), they will look very different compared to one another. Unfortunately I don't know enough QGIS to walk you through fixing it, but it shouldn't be terribly hard and somebody else can more directly answer your question :) – Erica Apr 3 '13 at 14:55
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    Did you turn on On The Fly Projection in the Options? – Jay Guarneri Apr 3 '13 at 15:04
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    @JayGuarneri - You should add that as an official answer to get credit for it. There are a number of aspects to dealing with projections and aligning layers in QGIS that need to be documented. This is just one of them. – Get Spatial Apr 3 '13 at 19:13
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    @GetSpatial Luckily the next release will turn on on-the-fly reprojection automatically. Just tested it! – underdark Apr 3 '13 at 19:29
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    @underdark: That's good to hear. I've been sticking with the stable release, but I can't wait to see how the next release turns out. – Jay Guarneri Apr 3 '13 at 20:49

If you turn on On the Fly Projection in the Options, that will make sure layers with different CRS's will line up correctly, assuming they have the correct CRS assigned.


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