Hi! My name is Dr. Michelle de Gruchy. I work in the archaeology department as a postdoctoral researcher on the Climate, Landscape, Settlement and Society (CLaSS) Project funded by the EU. Within the team, my primary role is to oversee the large settlement database we are constructing, but my skills in GIS, databases, remote sensing, programming, and data visualisation are all put to work on a regular basis to help the project team achieve interim goals.
I often do multiple tasks simultaneously to meet various deadlines. Today is no exception.
9:00 I log onto my home office computer and then remotely onto my computer in the department. The computer in the department acts like my assistant – completing one set of tasks while I work on others. For the last few weeks, the computer in the department has been helping me produce a land use map that shows how every 30-meter square piece of land across the entirety of Southwest Asia was used 6000 years ago. This work is part of a global effort called Landcover6K to produce a coherent global map of land use over time. These maps will help climate modellers increase the precision of their models for forecasting future climate change.
The first step of the mapping process, a land use classification system, was already completed by the larger, global team of researchers before I joined. Since then, the regional team the CLaSS project is part of has worked out which variables we need to consider to assess the potential land use of a space. Afterall, you can’t plant an orchard or a vineyard just anywhere. The same goes for other land uses: sheep pastures, agricultural fields, etc. Certain combinations of conditions need to be met: the right rainfall, soil conditions, slope, and so on. Mapping this information allows us to see potential land use. Later we will add more traditional archaeological data (sites, features) to model actual land use 6000 years ago. But one step at a time…
Months ago, I produced a sketch map of the potential land use using GIS. In the process of making that map, we refined our workflow and classification processes. Now I am scripting that workflow in R so that it is repeatable and reproducible. The spatial scale of the work and the resolution of the data is challenging to work with. It has been a constant process of finding ways to use the computing resources I have more efficiently, getting further through the script, then discovering the method is either warping the data or the script isn’t efficient enough and trying again.
Last night the script failed when it ran out of space to store the data it was writing, so today I need to start by clearing as much space as possible from the drive before I try an alternative method. While the computer deletes and transfers files off the drive for the next hour or so, I switch computers, check my email and login into the CLaSS Twitter account to see if there is anything to like or retweet.
9:30 Meeting! During the summer, second year undergraduate students in the department gain practical experience through work placements on research projects. We have a placement student working jointly with CLaSS and the EAMENA project to locate, map, and document sites in Syria. Yesterday, she started to examine the sites with Corona satellite imagery. Corona imagery is really useful for archaeologists because it is sufficiently high resolution to see even small buildings and walls, but it dates to the Cold War, so it allows us to see the landscape as it was decades ago. It is a bit like time travel: exploring a landscape that no longer exists and sometimes seeing archaeology that is no longer present. In this case, using the Corona imagery, our placement student has been able to see and locate sites that are now underwater in the Tabqa Dam reservoir.
9:45 Back-to-back meeting! Two of us stay on the call after the last meeting. We are finalizing a paper about urbanism and need to discuss some details about the figures.
10:15 One of the figures I am making for the urbanism paper shows multiple cities from across Southwest Asia at the same scale, so readers will be able to see and compare the extent of the different cities. I could make this figure using software like Adobe Illustrator, but I am using GIS software. This way the city plans will store geographic information and can be used in future maps.
12:00 The drive on the department computer is cleared, so I open the R script for mapping land use, make some modifications that I hope will resolve the issues from yesterday and start running the first sections. Then, I switch computers and continue working on the figure by drawing another city plan.
1:00 Lunch break!
2:00 Back at my desk, I quickly the computer in the department, then start drawing the next city plan. After lunch, this sort of digitization work goes well with a podcast. Thin Edge of the Wedge is a new podcast that started during the pandemic about Mesopotamian archaeology.
3:30 The computer mapping land use has run out of space again… I call the university’s IT department to discuss various solutions and we agree that it might be time to switch from my (very good) workstation computer in the informatics lab of the department to the university’s supercomputer.
4:00 Prof. Dr. Dominik Bonatz from Freie Universität Berlin is giving a talk on Late Bronze Age and Iron Age settlement dynamics in Jordan as part of ARWA’s ongoing webinar series. ARWA is an archaeological organisation that focusses on Western and Central Asia. If you are interested, ARWA record the talks are recorded and uploaded to their YouTube Channel. The talk by Dominik Bonatz should be uploaded soon.
5:30 I read the documentation on using the university’s supercomputer. There is a dedicated section on R that recommends running numerically intensive functions in Fortran or C and only accessing them in R. I have never used Fortran or C before, but it looks like Fortran might be related to BASIC. I have used BASIC before so I might try that first. PostGIS might be another solution. I definitely cannot run my land use script as-is on the supercomputer. I’ll look into this more tomorrow and decide which is best to learn/try next.