Remote sensing: the science of interpreting and identifying features from a distance.

By iLaria Marengo

Remote sensing is the fascinating science that studies and exploits the way the light coming from the sun (or from another source, e.g. radar) is first absorbed and then reflected back to the atmosphere by the objects on the Earth’s surface. Contrary to GIS, whose basic concepts are relatively simple and more “user friendly”, remote sensing is a sort of “niche” discipline because it involves more physics and maths, and requires skills in image interpretation. Nevertheless, remote sensing, coupled with GIS, is a powerful tool for understanding the spatial and temporal changes of the environment and deriving useful information to support environmental policies, decisions on management planning and strategies.

From the 5th to the 13th of November, the Ascension Island Government Conservation Centre (AIG CC) hosted a training course in remote sensing as part of the capacity building supported by the Darwin Initiative project entitled “Mapping Ascension Island’s Terrestrial Ecosystem”. The course was run by Dr Johanna Breyer, who works at Environment Systems in Aberystwyth, and has been contracted to support AIG CC in the delivery of the Darwin Initiative project. Environment Systems is a well-established consultancy company with years of experience in the field of remote sensing and GIS analyses. Johanna’s main task is the processing and interpretation of the high resolution World View 2 image (2 metre resolution) by applying a rule-based object analysis called image segmentation.

Data managers from the Falkland Islands and Saint Helena governments were invited to attend the course with the intention of becoming “intelligent consumers and users” of remote sensing tools. The aim of the course was to better understand the concepts behind remote sensing and apply them specifically to habitat classification. Central part of the course was to learn how the remote sensing analyst operates when carrying out the image segmentation and how the field surveyors proceed in determining and validating the classes of habitats on the ground and with the help of statistics. Time was spent in the office and on field trips to various locations in Ascension, with a very interesting off road traverse of Green Mountain from east to west.

satellite-map False colour image of Ascension (IR, red, green) to highlight the vegetated (red) and not vegetated (greyish) land. Clouds are visible in white.

signatureSpectral signature plot of water, bareground and vegetation. According to the signature the remote sensing analytical tools are able to identify and distinguish the objects on the surface.

There were many lessons learned from the hard job that Sam and Phil did in terms of habitat classification, for instance using systematic approach in deciding the sampling points and in assessing the habitat (use a standard density scale, consider the height of the species, carry out the assessment according to three altitude zones, etc). Similarly, Johanna provided the necessary basis to become aware of what a remote sensing analyst needs in order to set the rules for the image segmentation and extract the objects that will match the habitat classes. Interpreting a satellite image means being able to read and understand the spectral signatures that describe how the light is absorbed and reflected by the objects. In addition, ancillary information can help in identifying the objects, along with the knowledge of the local ecologist. At the end is a matter of aligning what a remote sensing analyst can extract from the satellite image and what the ecologist can see and map from the ground.


Field works on a lava flow which hosts the sooty terns


The spread of the invasive Mexican thorn bush on the slope of the Devil’s Riding School

Although the rule-based image segmentation is carried out using commercial software, QGIS, the open source software being used across the South Atlantic overseas territories, provides a series on interesting plugins, such as Semi Automatic Classification and Orfeo tool box, which can be used as starting tools for unsupervised/supervised classifications and for practising what was learnt at the course. Furthermore, free Landsat images offer the opportunity to perform spatial/temporal analyses in QGIS and detect land cover changes which affect the territories.

An important outcome of the course was talking and drafting best and standard practice for habitat classification with the use of remote sensing and ecological knowledge that can be applied across the South Atlantic UKOTs. In fact, the goal is to transfer what has been achieved in Ascension to projects that will be run in Saint Helena and the Falklands in the future.

Environment_Systems Darwin logoASI_logo




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Learning how to identify soils in the Falklands Islands

By iLaria Marengo

Soil is a natural, unique and multifunctional resource that provides and supports a range of ecosystem services, in the form of food and as a host for organisms and material that are important for human life. However, much we know about what we are standing on? How much are we aware of soils, their characteristics and properties? Can we use the soil in a more advantageous way for our activities without damaging them?

The Falklands Islands are an archipelago that spread across a bit more than 12,000 square kilometres and we know only approximately and generically about the soils within the islands. In order to start addressing this, a two week course in soil identification was funded as part of an EU BEST project, the Terrestrial Ecosystems of the Falklands – A climate change risk assessment (TEFRA), led by Dr Rebecca Upson and Prof Jim McAdam.

Rodney Burton, with 45 year of experience in soil survey, has travelled all the way south to train and enthuse representatives of Falklands Conservation (FC), Department of Agriculture (DOA), landowners and SAERI about soils. The aim of the course was to provide information and stimulus for the participants in understanding the basics of soil, its properties and processes, and how to apply that understanding to their everyday work and own specific needs.

The lack of a soil map is a noticeable and important gap in the baseline spatial information of the Falkland Islands. Hence, the main objective in learning about soils is to enable the participants to gather soil information (through description, interpretation and recording) to improve the first draft of the TEFRA project soil map. This map is an interpretation that Rodney Burton has produced based on the solid and superficial deposits geological maps.


The new skills acquired during the course are going to be applied to the identification and description of soil profiles for the main soil types derived from the TEFRA soil map. The idea is to do surveys at specific study areas chosen by Dr Stuart Smith, leader of the habitat restoration project at FC, add some opportunistic auger holes at farms where DOA is taking already soil samples for lab analyses and wherever leisure walks take iLaria Marengo in her attempt to walk each 1 km2 cell of the OS map.

The course was fascinating and enjoyable. It comprised of two days in the classroom, where Rodney gave a general introduction on soil genesis, classification, sampling, interpretation and a description of the soil survey field handbook. This was followed by a week spent in the field finding spots for the description and interpretation of soil profiles.

Each day in the field revealed something new. We went from some extreme conditions, such as snow and freezing strong winds, to a more “balmy” temperature of 8 degrees and absence of wind. We found that the soils are largely shallow, except in areas where peat accumulates. In Cape Pembroke we dug through almost 4 metres of peat but in the other locations we didn’t manage to dig more than 40 cm because the bottom (clay) was too hard.



Interesting periglacial polygonal features were spotted in all the location and in Saladero ventifacts were scattered across some bare land. Both features thrilled an already enthusiastic Rodney and were evidence that the geomorphology of the Falkland Islands is extremely rich in fascinating and puzzling features which are worth further investigation.



We would like to thank Rodney for the way he taught us soils, for his passion and the clarity of his explanations. Another thank is for the TEFRA project which made possible this course. We hope that as participants we can use the new skills efficiently and in a useful way.


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Turks and Caicos 2ND UKOTs GIS-Workshop: Learning, Sharing, Coming Together and Building Collaborations Across Territories.

By iLaria Marengo

Turks and Caicos Islands (TCI) hosted, from the 2nd to the 6th of February, the second UKOTs GIS workshop which saw the participation of representatives from the Caribbean (Anguilla, BVI, Bermuda and Cayman), Europe (Gibraltar), the South Atlantic (the project manager of the IMS-GIS data centre for Falkland Islands, Ascension, Saint Helena, Tristan da Cunha and South Georgia), Joint Nature Conservation Committee (JNCC), Environment Systems, and National Oceanography Centre (NOC). The event was fully supported and organised by the JNCC and by TCI Department of Environment and Maritime Affairs (DEMA).

The workshop entitled “understanding our islands: how to get the best out of our GIS and data” was focussed on achieving the following goals:

  • Providing members of TCI governmental departments with a training course in QGIS to allow them to become familiar with the open source program and demonstrate that it is a valid option to the proprietary and more expensive ArcGIS;
  • Identifying data priorities for TCI and finding solutions on how to address them in terms of GIS applications and data management;
  • Developing GIS and data management strategies to obtain long term benefits, such as standardisation of data, networking and data sharing, but also immediate gains, e.g. GIS and Remote Sensing based spatial analyses to support decisions on the islands’ policy priorities;
  • Looking at the main components of data management, which are people, data and systems and examine the way of tackling each one. The presentations on effective case studies delivered by each of the OTs offered “food for thought” and a starting point for discussion;
  • Drawing action plans to implement a sound data strategy in each territory and take forward the best practice of using GIS and Remote Sensing techniques as decision support tools.

The first two days of the workshop were entirely dedicated to the training in QGIS and had the participation of four TCI governmental departments: DEMA, Disaster Management, Planning and Surveying/Mapping. The training, led by Dr Katie Medcalf (Environment Systems) with the help of Dr iLaria Marengo (IMS-GIS data centre project manager), explored how to import the data, how to run basic vector analysis, how to create a map, and highlighted the best practice for structuring tabular data. In addition, practical examples of how Remote Sensing can be advantageous for evaluating environmental and ecosystem services were provided, as well as how spatial databases store and analyse geographic data more efficiently. Participants learned how GBIF can play a role for data sharing and how to upload/download data from it.

Besides the practical exercises, time was also spent discussing the current data management in TCI. Problems were identified and possible alternatives and solutions were found and translated into an action plan which should work as a starting point for the next months. The positive aspect of the first two days was the enthusiasm and the determination showed by TCI participants. Their genuine interest and desire to learn how QGIS works and how it can be advantageous to their project was a motivation for those delivering the training. TCI is currently facing two main problems: communication and data sharing among departments and consequently the lack of organisation and a data management system. The most evident and appreciated result at the end of the first two days was to see everybody discussing and finding solutions together round the table.

GIS 2015_1819Pic2Pic3IMG_0896

The excitement and interest in GIS and data strategy increased even further when the other UKOTs joined the workshop on the 4th of February. The discussion on how to make the most out of spatial data became wider and the presentations of projects and activities carried out in the Caribbean, Gibraltar and the South Atlantic were extremely inspiring.

Stephen Warr from Gibraltar wowed the audience once again with his demonstration of the advanced use of GIS and 3D modelling for environmental and planning purposes. Many people desired to have the drone and the plane with fitted camera that Jeremy Olynik from the Cayman showed in his presentation. Both are very useful technologies for getting high resolution data of areas that are not easily accessible. It was particularly interesting to learn about outreach activities from Rozina Norris-Gumbs which involve taking GIS to the schools and hosting a GIS day every year in BVI. Andre’ from Anguilla presented a superb use of remote sensing and GIS techniques to assess ecosystem services for his island. His motto “seeing is believing” was clear: to the politicians’ eyes maps realised from validated and sound data are more effective and compelling than reports. Mandy Shailer explained to us the way in Bermuda spatial data from aerial photography offer evidence and support for conservation and planning studies. iLaria Marengo, who represented the whole SA UKOTs, described the advantages of having a metadata catalogue online and how the data strategy for the entire region tackles issues such as data accessibility and data licence agreement.

Presentations from Tara Pelembe and Steve Wilkinson (JNCC), Katie Medcalf (Environment Systems) and Alan Evans (NOC) were very important as they described how their organisations can assist the territories in bidding for grants, addressing data management issues, providing technical consultancy on spatial analyses, buying basic equipment, and accessing bathymetry data and AUV instruments for further data collection.

The final key messages were that: a data system that supports the data organisation, management and sharing is fundamental; data need to be validated and quality checked before their use; metadata allow longevity and discoverability of the associated data; people should be trained and become familiar to GIS and Remote Sensing techniques as their application as analytical tools improves considerably the way of presenting geographic information and helps to make better decisions.

Although the workshop was very intense and stretched the full day, everybody had the opportunity to enjoy for one evening a local fish fry event close to a white sandy beach and turquoise sea. On Saturday the field trip to the pine trees restoration areas and to the nursery was guided by Naqqui, a real encyclopaedia of TCI plants and history, with the logistic support of Roddy, Luke and Kathrine. Finally, Sunday was time to relax on the wonderful beaches of TCI: sunbathing, swimming, bargaining the price of conch shells and then discovering afterwards that there were plenty on the beach!


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Intense and happy GIS days in St Helena!

By iLaria Marengo

It took quite a long journey to reach St Helena (8 hours on the plane from Brize Norton, 11 days in Ascension, and 2 days on the RMS St Helena) but it was an extremely fruitful and worthwhile trip.

The purpose of travelling to the island was to meet the community of data “collectors and users” and introduce to them the concepts of open source GIS, metadata recording and data management. In brief, the goal was to officially start the Information Management Centre (IMS)/GIS data centre and provide the islanders training/knowledge and understanding of the open source software QGIS. In addition, time was dedicated to support Dr Judith Brown and her marine team in preparing the data for a series of analyses that will contribute to the mapping of St Helena’s marine biodiversity. The use and application of GIS as an analytical and mapping tool will be very beneficial for the Darwin project that Judith is leading and will help in delivering a marine management plan for the island.

As in the Falklands and Ascension island, in St Helena there is also a major need to standardise the procedures of data collection, storage and management. The absence of an integrated and harmonised data system translates in duplication and dispersion of data across the government departments; difficulties in sharing and accessing the data within the departments and between departments and the local National Trust; and, in the worst cases, loss of data.

On the contrary, the benefit from having the IMS/GIS data centre is that people will share a data system with the same structure across the islands, will be able to find relevant information easily and quickly thanks to an online metadata, will be familiar with the way data are stored and gathered, and will be in the position of carrying out studies and research across the islands of the south Atlantic region as the data, thanks to the standards and similar procedures, will be highly comparable.

The IMS/GIS data centre consider training and advising people on GIS concepts, data standards and procedures first priority. In St Helena 20 people from the government and the National Trust attended the QGIS course. Everybody worked on their own data: the complete beginners experimented with GIS applications and unveiled its functionalities as an analytical and mapping tool, while the intermediates challenged the open source software to test that it is as effective as a proprietary one. The result was greater than the expectations: in two weeks not only people started using QGIS and felt the tool less difficult than thought but, above all, understood that successful data collection starts from as soon as the project outcomes are defined and it is based on a careful design and thinking of the structure of the attribute table, the variables that will be measured and the tools to be used to quantify the variables.

In addition, more than 30 metadata were provided for correspondent datasets. This is the first big step that will cast light on the accessibility, availability, distribution and quality of the data across the island. All in all, the weeks in St Helena were fruitful in terms of work carried out, collaboration, knowledge and skills acquired by everybody.

After two intense and happy weeks of GIS, everybody could see some results either in forms of maps, or in terms of understanding basic data management principles, or by looking at the number of records of metadata compiled.








The challenge now is to carry on, don’t loose the enthusiasm and keep in touch remotely and through the GIS Officer who is due to arrive in Jamestown in May. The passion, the effort and collaboration that people showed in St Helena are the right “fuel” for running and making the project a success!


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GIS Courses in Ascension and Falkland Islands

By iLaria Marengo

It took a couple of months to make it real but finally scientists and government and non-government officers in both islands had the opportunity to learn about GIS and the open source QGIS.  The course was organised by SAERI and delivered by Dr Katie Medcalf, Environment Director of Environment Systems Ltd. The audience was mixed not only because of the different professional background of the attendees but also because of the level of knowledge about GIS, which ranged from complete beginners to intermediate and advanced in GIS users.

It was therefore a challenge to deliver a course that could make everybody happy but at the end the results and feedback were very positive and it was a pleasure to listen and see enthusiastic people at the end of the course. Clare Cockwell, Protected Areas Project Officer at Falkland Conservation for instance said “Thanks again for a really good course. Having to stay strong today in order not to spend the day playing on QGIS” and many others commented that they “really enjoyed the course and found it useful

Essentially the main goal was to raise awareness of how GIS can contribute in supporting the analysis of spatial data (data with spatial reference). The course objectives were to provide the main concepts behind GIS and show some direct applications of GIS tools to data collected in Ascension and in the Falklands. The point was to teach people that data are not “just a table” but are much more. Geographic data is “spatial information” that can be seen in a spatial context and is likely to be in relationship (correlation) with other data that are collected in the same geographic area.


Using QGIS








Using real examples and data brought in by the attendees was much appreciated and here below some of the results that we obtained.


Coloured DEM of the Falkland Islands









Next is to keep on surfing the GIS wave by creating a GIS community and spirit in the islands, where people get directly involved in working and using GIS. The idea is to engage people in a sort of forum where they can exchange their experience and knowledge on GIS tools, they can post their “discoveries” about how to carry spatial analysis, and ask for help. In addition, the last initiative is to open one day a week a “GIS clinic” for problem solving.

Keep on watching this space for more interesting news and activities in the South Atlantic region!!!  

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