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In some of the exercises we used a river layer that was not a line layer type but a polygon type.
I would like to know how you converted the line vector layer of rivers to polygon to be usable with tools like intersection, etc. please?

I found a command: "Lines to Polygon" under Vector->Geometry tools. But it seems to do something else, and not what I need.

Thank you,
Sarvenaz

To download the files from the AWMC you have to right click the link and save link as.... This will save the correct file. Unfortunately, it is not possible to save the whole folder this way. So we have to do it for all the files associated with the shape file we need.

Maybe there are more people with MAC who dealt with this problem:

"I manage to draw the edge of the Traianeum, but I couldn’t complete the drawing because MAC hasn’t got a right click on the mouse. Normally ctrl+click works as an equivalent for the PC right click, but in this case no luck. I can’t get out of this tool and consequently I never shows in the attributes dialog."

This problem seems to be known and there are some possible solutions:
https://gis.stackexchange.com/questions/341475/closing-polygon-with-right-click-on-mac-os-using-qgis

Just because it fits to the MAC issue, here you find a short list of MAC shortcuts for QGIS:
https://gist.github.com/ThomasThoren/94526844767be6b87ed1b37c83eade97

I would like to know how we can add the information of another layer at the location of my points to the attribute table of the point layer.
Imagine that I have a point layer for my sites. then I create some other layers (both vector and raster) from the other sources of information that I have. Now I would like to know the value of all these layers at the location of my sites and to add each one as a variable to the attribute table of my sites (point layer) for further analyses.
For the vector layers I understood that we can do this via the intersection tool (please correct me if I am wrong).
But how about the information of a raster surface?
I have created the slope map and aspect map for example. and now I want to add the value of the slope at the location of each site in a column in the attribute table of my point layer.
How can I do that? I am sure there must be a way!

Thanks,
Sarvenaz

Dear,

it seems that my end result of Module 9 is not entirely similar to the envisaged outcome. After retrying this module twice, I suspect that the problem is situated in the raster to vector conversion. Once I'm in the new vector layer, it does not display the two layers. Despite the fact that I can filter 0 or 1 (suitable) in the attributes table, it never shows the filter in the layer panel. If I continue working with this layer, it does not give the expected solution at the end (even when I adapt colours etc.). How do I solve this?

1- In Module 9.1.3 we tried to rasterize the vector layer that we had already vectorized with Raster to Vector tool.
For me Raster to Vector worked fine without a problem, but when I tried to Rasterize it again the result is a raster layer that has only half of the data inside. In the layer pane it shows both fields as having the value 1. (where is normally has to be 0 or 1). and when I try to read the value for different cells I realize that the black cells have value of 1 and the white parts have no data (no Value). So it means the parts with the 0 value are deleted and considered similar to the no data part of the map. and that we do not have several values of cells in our raster any more. this raster therefore is not similar to the L09_suitable that we started with.
(I put all the parameters like the one described, and don't understand where the problem comes from)
Also it means if our vector layer had several different values (0,1,2,3) probably those would have also been lost. right?

2- A second question about the same tool: in the settings of the tool where we have to define the width and height of the generated raster, in this example we used the size of the original raster that we had. But what if I want to rasterize a vector layer that never had a raster covering exactly the same are (like a vector layer of the roads or rivers) and now I would like to rasterize it. How can I find out what I should put in the field of width and height for the resolution of the map in this dialog box?

Thanks,
Sarvenaz

Hi, I have tried vector analysis to create a new vector file that contains only the polygons where suitable has the value of 1 but I don't know what is the specific filter expression that we need to do this. I am not sure if I am doing it the right way?

Thank you!

Is there a way to change the language in which the downloaded QGIS is used? (I have been working in QGIS downloaded in my native language, but I'd prefer to use the English version as I find it easier to follow the Modules in English). Sorry if it is a silly question...

One participant thankfully pointed to a mistake in 6.1.4, step 5, which said: "Set the attribute value to Minor Road and certainty to No."

We now corrected the advice, so it is really telling you, which attribute value has to be set as intended: "Set the class attribute value to Minor Road and certainty to No"

So if you struggled at this point, please have a look at the steps again, it should now be possible to follow them completely. Although the problem is solved, the issue will stay open some days to point to that problem.

Perhaps is just me, but I don't seem to be able to find the shape file for Italica. There is only a .tiff in the raster folder

Hello,
I have a question regarding the possibilities of QGIS for Network Analysis.
I would like to create a layer Showing the Cost Distance on a Network (in this case Roads).
Meaning that I have a Vector Layer of the Road networks. And I have a point on the map where I stand (or my research site is)
and I would like to calculate the distance of the points of my road network to my site in terms of the travel time (Cost=travel time).
I would like to create this map as a layer where I can show with different colors the map network depending on the distance of its points to my site. For example meaning that all places on my roads network that are 2 hours away from my site will have the same color. and all points 1 hour away have another color (I was thinking of using a symbology with continuous color to show the gradient of the change in distance for the whole network).
I think this result has to be a raster file because it needs to be calculated for all the pixels on the road network.
Do you have a suggestion how this can be done? or is there a better method to have a map where I can show these equal distance contours on a network?

Thanks,
Sarvenaz

I'm looking for a suitable base map for my project maps, but going round and round the houses and getting nowhere! Google Earth hybrid is just about ok but too dark and obtrusive. I managed to lighten it slightly using layer styling, but it's still not really good enough. Most of the styling options don't seem to work with it.
I thought Natural Earth II would be good but I can't zoom down on it far enough. Can I alter it in some way?
I looked on AWMC. I found their elevation maps but they don't go far enough east. The map they use for their a la carte app does, but I can't see how to download it.
This is the sort of thing I want: https://commons.wikimedia.org/wiki/File:BactriaMap.jpg#/media/File:BactriaMap-es.svg
The base map appears to come from USGS GMTED2010. I've looked on their website. This looks to be the right page. https://topotools.cr.usgs.gov/gmted_viewer/viewer.htm I've tried to download the relevant tile but nothing happens. Perhaps I need to register or pay?

I'm wondering if, at our meeting tomorrow, you would be able to demonstrate downloading and modifying USGS maps to make them usable. I'm not having much luck so far. Thank you.

Hi, I am doing Exercise 7.2.4 and I can't find the vector L07_BTN100_rivers in Module 7 exercise data, I can only see L07_BTN100_rivers_Almanzora and when I import it, this only shows the rivers in the area of Almanzora, not in the whole peninsula so my map looks different from the examples provided.

1- I would like to know how I can export the data of the Attribute table to an excel file?

And vice versa:

2- how can I import the information of my database that I have made in excel for my sites and add it to the attribute table of the point layers of my sites in QGIS please?

Thanks,
Sarvenaz

I've installed QMS plug-in, apparently successfully, but I can't get QMS search icon to work. I've tried going through the web tab but that doesn't work either. What am I doing wrong?

I am working on module 6 and I have a question concerning the drawing of lines/polygons. Is there a way I can go a step back while drawing (e.g. if I placed one point wrongly) or can that only be corrected afterwards with the Vertex Tool?
And also: Can I delete a point after I have finished drawing?

Thanks!

Is this a possibility to ask questions concerning the course, which will be commented by the lecturers?

Hi.

I have a problem in module 9.2.1.
When I try to use the intersect tool combining 09_Landuse_Tagili.shp as ''Input Layer'' and suitable_vectorized as Overlay Layer, this mesagge appears:

"Feature (27) has invalid geometry. Please fix the geometry or change the Processing setting to the "Ignore invalid input features" option.
Execution failed after 0.04 seconds"

and the intersection doesn't work.