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Module - M1: Processing geospatial data

CityLoops
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In any case, it is possible to change/edit the processed document details, right?


Yes, that is correct for the datasets. You can also edit some data for shapefiles (names, descriptions, tags etc.), but so far not the data that you've added during the processing, which would be on the data quality (completeness, update frequency etc.). (I have made a task for it here to discuss if we can implement that.)


Ok, thank you!


Hi!
I processed a file of districts in Mikkeli and the files did not have names for the districs. Is it possible for me to name the districs, when I look at the single item (you can see the name of the district on its own map). How can I do this?
Thanks, -Johanna


Hi Johanna,
I suppose it has to do with this file, see map view? (Usually, if you problems with a file, it is helpful if you share with which file by adding the link, then we can easily check, thanks.)
I see that 37 entries with 4-digit numbers were created. It is not possible to rename them once they have been created. BUT, I can reset the file for you. That means the reference spaces (and associated data, which in your case there isn't any yet, but good to know for the future) will be deleted. You can then replace the numbers with names, e.g. in mapshaper or QGIS, replace the previously uploaded shapefiles (by editing the document) and process them again. Do you want me to do that?


Hi! Thank you Carolin. I tried the mapshaper and could not change the name of the districts with that. I probably need to check this out with Vuokko, she has a program with which we may be able to rename the districts. We will still look into this. Please do not reset the file yet.

BR, Johanna


Hi Johanna,
Ok, noted, thanks. Just let me know once you need the reset :)


Hi there,
Quick note: if all you want to change is the names you might also want to try out LibreOffice which can simply open the spreadsheet file that contains the data (dbf file). Attached a screenshot of what it might look like.
Doesn't really matter which tool you use, but just to let you know that this might be an easy one.
Good luck!


Hi!

Thank you Paul for the tip. I was able to change the names through LibreOffice, but it could not save it as the same file mode (dbf, the names where lost, I tried) but it saved the information as a ods-file. Now I still don´t know weather this shows the information in the right way in the maps, so we will be looking into this with Vuokko.


Hi Johanna, thanks for your message. I have found that you need to take care to format the header row correctly. You will see something like

title_of_column,type_of_data,length

For instance:

Suburb_name, C, 50

(that would be a column with the name "Suburb_name", which is a Character column (C), and 50 characters long)

Sometimes the number needs to be increased if you add longer names, and you need to make sure it is a C column if you add text. I don't know the full syntax either and you may or may not want to dig into this -- other tools may be easier to use but in any case it is always good to try things out I think. I hope you can sort it out together with Vuokko!


Hi!
I´ve bee too eager to process stuff without thinkin it through properly, sorry. I processed a file: Geo-localisation of waste collecting and treatment in Mikkeli. It has information about the slush collecters in different districts of Mikkeli. I really think they should be taken out of the file. This is because they work in the whole districts area and the GPS coordinates might refer to their home-office. Anyways, it´s insignificant information I would like to take out. Can you please delete this process? Is it possible for me to do it on my own, since I´m probably going to make mistakes again :)


Hi!
Can you please delete the previous processed map on the districts now? Vuokko was able to change the names of the districts from numbers to proper names with ArcGis. We will process the map again. Thank you for your help. :)

-Johanna


Hi!

We have processed last week many shp-files related to land use in Mikkeli (actually most of layers are extracted from CORINE data but there are also e.g. roads and railways data). However, status of many prosessed files is still "scheduled for processing" probably due to big size of data? Should we do something to these shp-files? Or are they even relevant for this SCA analysis, do we need these data during the process? What do you think?

  • Vuokko

Hi team Mikkeli :)

@Johanna:
1) I've responded in the respective file.
2) Done, deleted the districts, see my comment here.

@Vuokko, yes this has to do with the file size or the number of reference spaces. If they are too many, then we (admins) have to confirm that they are indeed relevant. For the land use, as discussed, this was too detailed and Johanna said that you are working on reducing the levels of detail.
As for relevancy, as mentioned in the course, if you don't have data that you can link to the shapefiles, then they are probably not relevant. Land use on its own is relevant, to get an understanding of the context and it will also have its own place in the report.

Hope this helps! Do let me know if there are specific files that you have questions on, by commenting in them directly. Thanks and good luck!


Hi there,

Quick addition to Carolin's comment: I saw that e.g. the railroad shapefile is very large - almost 16MB - but it only contains a few simple lines. I imagine it is incredibly detailed/high resolution. I would recommend reducing the level of detail so that the file becomes much smaller. In general it is good to play around a bit with level of detail vs file size to be able to make a good trade-off. 16MB may not sound like much if you store it on your hard drive, but if a visitor wants to open a map showing the railroad they would have to first download this 16MB file, and then the browser has to parse this and display it on the map -- this makes it all very large.

For inspiration, see here the metro in Medellín - shapefile of less than 20 Kb - and the boundary of that same city - 315 Kb.

Do note that some things necessarily need to be quite large - because they contain lots of different polygons - but it is important to evaluate file size critically to ensure it is not just huge because the original data provider uses a very high resolution.

Hope that helps.


Hi all, quick update. I accidentally found out that your railroad shapefile contains "Z coordinates" which means that it contains the elevation of each line as well. This is also likely one of the reasons it is so large. This information will not be needed for our purposes and it would be best to remove. I am not fully familiar with this but found a somewhat related discussion here. I adjusted the suggested command a bit because this particular file is no polygon, and this seems to work:

ogr2ogr -F "ESRI Shapefile" output.shp locationtracks.shp

You might want to try it out yourself and perhaps this is also something that can be done in your GIS program, not sure.


Hi Carolin and Paul,

Thanks for your help! I have now worked with some files.

I replaced these files with smaller and I also tried to process them again:
- Forests in Mikkeli
- Water bodies in Mikkeli
- Road network in Mikkeli
Now I can see them on master map but there is notification: "There was an issue processing this shapefile. This file was already processed - we can not process it again". Status is still "scheduled for processing". I´m sorry, I hope I didn’t confuse the system!

I also removed the multitrack railway data, because I think that smaller data "Railways in Mikkeli" is enough for this purpose.


Great Vuokko! I have sorted out those errors - you can now see your maps: road network, water bodies, forests.

And great work with the size reduction -- these files are very fast to load and process!


Great, thank you!


Hello! I have uploaded a processed file which after I realized that there was an error in my conversion calculations for 2 bird species and I was trying tu replace the previous file uploaded for another with the correct values (deleting the first one and uploading the new one) and it doesn't change the values that are in the charts/table below. Can someaone please help me with this?


Hi Paula,
Oh, well, that can happen. Let's see how we can help you. In general, it would be very helpful if you always linked the file that you are referring to, so we can easily check, and even better, if we discuss any issues in the item itself.
I assume it is this one? I've responded there.

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