Mapping lobster biomass and the utilities/services on Tristan da Cunha. QGIS reaches the remotest inhabited island of the world!

by iLaria Marengo

Working with GIS and as data manager is exciting, but it becomes even more when the job is taking you to unusual places such as Tristan da Cunha, a small volcanic island in the middle of the Southern Atlantic ocean surrounded only by other two smaller islands, Inaccessible and Nightingale and, further south, Gough.

all_sa_ukots  tristan-group

The project to realise an Information Management System and GIS centre for the South Atlantic UKOTs has reached its final destination and a proper conclusion after three years of life. Getting to Tristan is all but easy thus it took time to arrive, meet the small community and bring QGIS and a flavour of data management in such a remote place.

The QGIS course was not planned in advance but day by day once in Tristan. In fact it was thought that could be more effective to tailor the lessons according to the main needs and existent GIS skills of the users. The majority of the time was spent at the fisheries and electricity and plumbing departments. The directors showed a great interest in receiving a GIS course and their requirement were very specific. They ranged from being able to map lobster biomass per monitoring station, lobster catch (total and average per fishing season) and effort around Tristan, to the network of services, utilities and structures of the settlement of Edinburgh of the seven seas.

total_catch_tristan   tristan-tourism

A series of maps (geological topographical and aerial) have been georeferenced to provide the students with a reference background. Currently the main need is to find a clear image of the settlement as it will help digitising the electricity, water and sewage networks, the buildings and other utilities such as substations, streetlights, stone water tanks and so on.

crawford_map  geological_map

Unfortunately on the island internet is very limited and not reliable. Among the whole South Atlantic UKOTs Tristan has the smallest band width, hence it is virtually impossible to download images or connect to google earth like everyone else would do in the other territories. In terms of GIS a poor internet is partly a limitation as getting new plugins, google maps or updates of the software becomes very difficult. The solution is to work with the long term release releases and get large data (such as imagery) saved as offline images and shipped in on DVDs.

In parallel to the GIS course, time was spent in harvesting metadata. The departments involved in the training course provided metadata about their data and RSPB kindly helped in gathering information on environmental data captured throughout the years with the help of the local conservation department. Almost 40 metadata records were collected and will be available on the metadata catalogue online from the end of November.

Finally, few hours were dedicated with officers of the tourist office and advice on QGIS mapping techniques was given to improve the current maps given to the tourists landing at Tristan. Using QGIS will make mapping much easier and quicker than what is now, entirely based on graphic design software.

The GIS course delivered in Tristan focussed on simple and basic tools that could help straightway the GIS users in achieving their requirements. Indeed, more can be done with GIS but the overall idea, after being on the island, is to let the GIS grow a step at a time according to people’ needs.

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Geocaching in Tristan da Cunha

By iLaria Marengo

Learning about projections and coordinate systems, navigation techniques, compass and bearing, and the use a Global Positioning System (GPS) nowadays can be a bit funnier thanks to geocaching, a modern version of the traditional treasure hunt.

In brief, geocaching consists in getting a pair of coordinates, loading them into a GPS and using the device to navigate to the point where a small box, the geocache, has been hidden. The cache is a small waterproof box and generally contains a logbook and the treasure, which usually are tiny items that have a particular meaning for the person who placed them. The people who find the cache are free to take its objects (except the logbook) but they must leave something of similar value.


It was an unexpected but pleasant surprise to find out that in Tristan da Cunha, the remotest inhabited island in the world, a series of caches had been hidden by the local tourist office as part of a commemorative geotrail. The 200 anniversary of the British Garrison in Tristan da Cunha was celebrated with parties and various initiatives and setting up a geotrail was one of these.

The opportunity of being the first to do the geotrail was then seized and seen as the best way to engage the oldest students of Saint Mary’s School to have an open air geography lesson about projections, maps and the use of GPS for navigation and marking spatial objects. Thanks to Anne, the head teacher who authorised the half day out, and the help of Sarah, fisheries officer, the kids in class 5 were taken around the settlement to learn how to use a GPS, how to mark a waypoint, enter coordinates of a point and navigate to it in order to find it. The day before the “hunt”, the six pupils were asked to write on a small piece of paper why they enjoyed living in Tristan. The papers would have placed in each cache as treasure for the next geocachers.

ticket_geotrail   ticket_geotrail2

A map of the settlement with a sketch of the geotrail, the coordinates of each cache and a description of the importance of each site in the context of the British garrison period was given to the kids for reference.

geotrail_leafletThe kids of class 5 learned very quickly how to use the GPS in the two hours of cache hunting and navigation. The day before rained heavily, however the muddy and soaked fields did not spoil the day and the amusement of the kids. The hope is to have passed to the kids a new skill which they can well use in Tristan and in any job with conservation, fisheries and public work.

kids_geotrail1   kids_geotrail

It would have been great to show the kids how to map the points in QGIS. However, there was not enough time to plan for a GIS lesson, which was instead given to some of their parents!

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