Process the following files in your city’s processing queue or by finding them in the general one:
- city boundaries: Select your city boundary as shown in the third video. You can also do so here.
- city districts
- city neighbourhoods
- land use
Note: There is NO need to process a shapefile that has NUTS 2 or 3 or country boundaries, as we already have processed them in the system.
Outline of the video
- We will look at how to process GIS shapefiles
- First part of processing queue options and the goal is to now convert it into something that the system can read.
- Select a file: You can search by keyword or name of the city; "Good for beginners" is auto-detected by the system that this meets certain criteria that this is rather easy to process
- M1:08, Example of Processing a file; File displays a preview image
- Either you have lines in the shapefiles (e.g. rivers), dots (location of a plant or farm), boundaries (e.g. city or zipcodes)
- Technically speaking, each item on the map represents a "reference space"
- reference spaces are important for database structure of our system. It is any type of space, of any space, that we would like to have a record on. Examples: single city, single bus stop, single country. These can also be linked and make relationships between them. We can link material flows and stocks to reference spaces or images.
- Important: Whenever you want to add stock or flow data, the reference space that you are covering in that file needs to exist first, otherwise the system doesn't understand what you are talking about. E.g. CO2 emissions in the City of Cape Town, then the system needs to first now "what Cape Town" is and what the boundaries are. Or there are 10,000 people using a certain train station, then the system needs to know which train station that is. That means that GIS processing is a fundamental step for processing all other data.
- M3:35, going on with the example, it can be seen that the info is roughly outlined and it shows that there are 18 items and 7 properties. This happens behind the scenes in the shapefile. The 18 items will translate into 18 reference spaces.
- Start thinking about if that makes sense and if that can be expected.
- Scrolling down, the table shows the shapefile content. 7 properties translate into 7 columns. The 18 items are 18 rows.
- After the check is done, you can assign the item to yourself.
- Then there are two options
- 1: yes, shapefile looks good
- 2: no, a different file should be uploaded
- Here, everything looks good and we can go to step 2. Now, the column that contains the name of the items has to be selected. Then click "next".
- M7:09, In case the name is not there or incorrect, you need to go back and correct the names. There are a number of ways to do that.
- There is a handy website: https://mapshaper.org/ You can upload the file and edit the properties and download it again OR do it in any GIS software. Important: This needs to be done BEFORE loading the file into the system, otherwise the system thinks the incorrect ones are the right names and will use those.
- M7:47, if this looks right, go to the next and third step. Here you need to check some document details.
- The document title comes from the document itself. Which is generally ok, unless it is all caps etc.
- The short title is used for the legend in the map. It should only be the key thing that is in the shapefile, for example, rivers, bus stops, airports, administrative boundaries.
- Description, you can expand on what it says there.
- Tag, should indicate what we are describing in this shapefile. Multiple tags can be added.
- M9:36, Data quality
- Data coverage: e.g. include all rivers or not. Unsure can also be selected. In some cases "completeness" may not make sense, then you select "not applicable"
- Known flaws and limitations, e.g. something isn't detailed enough
- How frequently does it change, e.g. rivers don't change that much, it could be every 2 years or even "not applicable"
- Finally, save and publish. The system then takes the input and draws it on the map.
- Dots and polygons will be very obvious. There is a map editor in which we can highlight them.
- Under the table it can be seen that the system imported the 18 items. You can click on an individual one and see an extra map and all the meta-data.
Types of shapefiles
Outline of the video
- Types of shapefiles and the way to process them depending on their nature of content.
- 3 types: Each element is an individual space, Elements should be grouped together, The entire shapefile represents a single entity
- M0:13, first and most common type: Each element is an individual space
- Example: city with individual suburbs, each neighbourhood represents a different space;
- After the work item is assigned to you, in the next step, the system asks how this should be processed. In this case, we want to make 10 individual spaces, because the file has 10 items. Now the column with the name of the space has to be selected and clicked on next step, before completing the processing as learned before.
- M1:30, example of land use for the second type of shapefile: Elements should be grouped together
- This is not a different identity, but in the way in which they are classified. In this case, it is 3 main groupings into which the file should be split up.
- The way it works, in step 2 of processing this file, you select "group spaces by name". Type of land use is the correct column to choose in that example. Once saved and published, it distinguishes the 3 types: urban expansion, urban and rural.
- Classification systems are used for land use, soil type, mineral deposits, vegetation type.
- M5:00, third type of shapefile, which is The entire shapefile represents a single entity
- Example of a network, where we don't care about the individual items, but the network as a whole, e.g. transmission lines, water and sewer pipes, gas pipes; It helps to consider how it is named.
- In this example, we need to save it as "group into one single space". The table disappears because it is no longer relevant.
- Saving and publishing it brings us to the entire network. The geospatial information is not lost, but it records it as one network.
- M7:41, we have seen three different types, but we have to be careful, because the ones that represent a network can sometimes be grouped. Example: Network of the train network. Segments are part of a certain line. In that case, it makes sense to split them up and group them by names, in this case, the name of the train line.
- The 52 different segments come out into 5 different lines.
- This may make sense for train lines, but also road networks, but only if you have the big highways. The entire road network of a city is too detailed and in that case it makes sense to upload as one road network. Important to think critically about what would be done with it.
- M10:10, recap of three different types
Outline of the video
- City boundaries are the third item on the list (after shapefiles and geospatial spreadsheets)
- Exploring the maps section first
- Whenever a dataset is processed, it will show the item next to it.
- When going to the master map of Johannesburg, the master map does not appear unless it knows from which document it can take the administrative boundaries for the city.
- Go to the administrative boundaries section to see if there is already an appropriate document, e.g. one on municipalities.
- In order to tell the system which boundaries to select, we can tell it from which file it should select the reference space. That means that this document also already needs to be processed.
- Assigning the city boundary is creating a proper linkage to a created reference space from a processed shapefile.
- This can be done in a city's data processing section and clicking on "city boundaries" and then selecting the processed document in the yellow highlighted field.
- Afterwards, you can click on "select these boundaries". This now loads the baseline map for the master map.