Georeferencing the UAE maps

On the 23rd of November, our class met in the Center for Digital Scholarship at the NYUAD Library, to discuss and exercise on georeferencing. Georeferencing is the process of matching the coordinates of a map or aerial photo with an existent set of coordinates (e.g. an old map can be matched – overlapped, superimposed – with the occupying reality of the old map’s geographic coordinates).

Matt Sumner a Data Services Librarian at NYUAD lead the ArcGIS workshop concomitantly with the class discussions on georeference, data comparison, and limitations of such a process.

What a georeferencing software does to maps is very similar to what an OCR software does to images: it makes them “digitally useful.” This means that the resulted digital map can be engaged in other digital exercises: it can be compared with other digitized maps or, as I said above, overlapped with them. Doing so helps creating a visualization of the land transformations in time. We can see whether the borders between two countries have stayed the same, for example. Or, we can look at an evolution of land distribution over time (for climate change research purposes). Using a georeferencing software (such as ArcGIS) helps doing all that. During the class, Matt showed us which are the steps for doing so and georeferenced an old Soviet map of the UAE.

The maps we were working with (already scanned and ready to be used) were easy to work with because each of the four corners of them had the geographic coordinated written down. From there, all we had to do was to match the current coordinates with the corners of the images. However, in case we didn’t have the coordinates available, what we would have had to do was to find reference points (a building, a street, the center of the city) that could help with the overlapping. After both the current map and the old map were imported, the workspace looked like this:

01
Red contour of a recent UAE map (front); old Soviet map of the Sharjah Emirate (scan, background) – before georeferencing

In order to place the map on the contour, we had to create four referencing points which would be placed at the coordinates specified at the corners of the image. Then, once these were created, the last step was to match each point with its corresponding corner and …

Voila! With very little disagreement (because each corner pulls the image towards itself), the two objects overlapped! Now it’s time to look how “things” changed over time.

02
The two maps (red contour and scanned image) overlap

The Soviet map was created in 1978 with materials from 1975, while the red contour is not older than ten years. We can clearly notice some changes (and imagine if we had the physical map and not just a contour how many changes we could have spotted!); we can see how the lakes have diminished in size, as well as the fact that the coastline has expanded.

Matt had more scans like this (and he has also placed all the other necessary reference points before), so, in a few minutes while me and my classmates were discussing about the interesting things we learnt, he created this:

sharjah-sheet-indicated
The collection of Soviet maps of the UAE, georeferenced on the current shape of the country

As a fun exercise, and because we were lucky to have a copy of it, we also georeferenced a map of the city of Abu Dhabi dating back somewhere between 1964 and 1971. The map provides a simplified shape of the city, together with important landmarks and streets which helped us georeference it (because we had no coordinates for it).

fncb-map
An old map of the city of Abu Dhabi overlapped with a current map of Abu Dhabi (the process is not complete)

We’ve learned some interesting facts about mapping in general and about georeferencing during the ArcGIS workshop. Some things that I found note-worthy are:

  • people believe what a map says. Although, we have seen that this might not always be 100% accurate;
  • in georeferencing, we have to make compromises and choose between fitting the entire map in a shape and having “disagreements” with the contour, or perfectly fitting a part of it and neglecting the rest;
  • a map can be seen as a “purposeful simplification of reality.”

Networks, Maps, and NodeGoat

I haven’t been around in a while. The reason for that is that many changes have been taking place and a lot of information had to be sunk in before I wrote this post. Last time I was discussing the presentations on corpus analysis, and little did I know that it was only the beginning of this field called digital humanities.

There is a whole lot more. During my last couple of classes, I have learned about networks and maps – and what I learnt is only a small part from what I learnt is to be learnt. But I am still glad I have a starting point now.

Let’s begin with networks.

Networks – in digital humanities – is an amazing concept. It allows one to visualize all what they read about in a book, on Wikipedia, or in a table. It visually connects the information and provides an easy, logical form for understanding its content. Before I move on to its use in different types of projects, I would like to give a short definition and description of a network.

A network consists of nodes, edges, and relationships. A node is any item in our data that we are focusing our analysis on, it is the person/ object/ phenomenon of our study. Edges are the links/ connections between two nodes and show that those nodes have a common characteristic. Lastly, the relationship is the idea behind the edge, the criteria used in determining the connections between the nodes before the visuals are displayed. An easy way to picture a network is by thinking about one’s genealogical three: each member of the family represents a node, each arrow (or double arrow) from one to the other is an edge, and the meaning of the arrow (as well as the position of one node in comparison with another – since the genealogical three is a hierarchical structured network).

An example of what one can do with networks (and a bit of programming knowledge!) in digital humanities is the amazing project by Silvia Gutiérrez, New Maps for the Lettered City. A few blog posts ago I referenced to the Mapping the Republic of Letters project created by a team of researchers at Stanford University, which offered a visualization of Republic of Letters writers’ travels – which could be further analyzed and interpreted. This new map, which looks at members of the 19th century salons in Mexico, is doing even more than what the Stanford project did. For example, the generations’ problem shows who met whom and where, and what literary movement(s) and salon(s) were each of them part of. This is extremely helpful for thinking about the human relationships that were formed in each salon and what new ideas might have each of them brought it from other salons and/ or other literary movements.

Coming back to the Digital Humanities class, me and my classmates, together with our professor, have started a network project on our own! We have used nodegoat to introduce our data and create a network visualization. The subject we chose was Egyptian Cinema and the categories of nodes we created were multiple: title of the film, author/ other authors/ main cast, release year (the very first, despite the country/ region). Then, for each person we have decided to attach some information which would help us study the social relationships between them. Thus, we added their spouse, date and place of birth and of death. Towards the end, our database looked like this, with 44 entries:

egyptian-cinema-jpg

The network project had two distinct parts: data gathering and network visualization. In order to gather all the information on each film, we created an excel table where we introduced most of the required details (title, author, year) and then introduced them in the Film or Person forms on Nodegoat. Once we filled in all the data for around 10 films each classmate, we were ready to test the network visualization functionalities of the website! In the picture below you can see a social relationship network visualization of the connections between different film directors. Where they are more connected (the example of Chahine Youssef, Mazar Ahmed, Kamal Hussein are relevant in this sense). Other authors, such as Mohamed Khan, Abouseif Salah and others seem to be less-connected with the rest of the Egyptian film industry.

network1

But wait! Nodegoat only displays the user’s input. The reason why some authors look to be less well-connected than others is simply because the “Person” category for each film was not filled accordingly, which is an important detail to remember. If the data collection would’ve been done more in depth, then our social network would have looked terribly different! (And we might have discovered that, in reality, they are all inter-connected with each other).

network2

Above, you can see the films – out of all the 44 entries – that were associated with the film director Mohamed Khan. In a specific research project (on the themes addressed in various films) – such a network would serve the analysis and exploration of the research subject by providing an easy visual mean of analyzing it.

All in all, NodeGoat was interesting to use. After also checking out Palladio, I believe both websites are handy and can generate basic good-quality visualizations. Some shortcomings of NodeGoat would be:

  • the large amount of manual labor one still has to put in gathering and introducing the data (instead of simply giving it a .csv file to read we have to manually introduce data on each film which takes up quite a lot of time). In comparison with a web-scraping software it looks terribly inefficient to have to google the information and organize it;
  • its limited visualization options (only geographical and social);
  • its unnecessarily pop-up menus and tabs which slow down the process of introducing data.

However, considering the fact that it is a start-up website and my class purpose was only learning through experience, NodeGoat helped in showing us the “behind-the-scenes” of network visualization.