Ian Lockwood

MUSINGS, TRIP ACCOUNTS AND IMAGES FROM SOUTH ASIA

Posts Tagged ‘GIS

Geospatial Teaching & Learning 2018

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Geospatial Teaching & Learning website home page featuring a  Landsat image of one of my favorites areas-the Sundarban. Processed by the author using raw NASA tiles in an ARCGIS environment. Click on the image to access the website and PDFs of presentation folders.

In February, the American School of Bombay held its regional technology conference and workshop ASB Unplugged. The three days of presentations, interactive sessions and discussions gave me a chance to observe and check in on a school well known for into innovative use of technology in the classroom. I participated in the event and was also presented my workshop entitled: Geospatial Teaching & Learning: Opportunities, Applications and Ideas for International Educators. The workshop offered an opportunity to review recent developments in the fields of Geographic Information Systems (GIS) & Remote Sensing (RS) with a special emphasis on potential applications for international school teachers. Geospatial fields continue to experience rapid changes as technology develops, data become cheaper and more assessable and software is easier to use. That is good news for educators interesting in incorporating geospatial applications in their classrooms.

There were several themes that were updated or new in this workshop:

  • Story Telling With Maps: One of the most useful aspects of the workshop focuses on how interactive stories based on maps and imagery are a great way to highlight the cases studies that are central to the teaching of DP Geography. These can be viewed but can also be created by students and teachers as a means of developing knowledge about case studies that are not well publicized. ESRI’s Storymaps and Google’s Tour Builder are two excellent web based options.
  • OpenStreetMap offers opportunities for students and teachers to get involved in mapping their own neighborhoods in a wiki-based global mapping project. Users can then access this spatial data and a vast treasure trove of vector data that has been contributed by users all over the world, as a part of a local-based research project.
  • New Data Sources: I highlighted some of the emerging sources for spatial data. On the workshops companion site I have a long list of data options and surely there are numerous other sites that I have missed. These are global in outlook but there is a focus on South Asian geography issues. I shared the exciting emergency of Planet, a US-based company that has a constellation of 150+ micro satellites that are imaging the earth and providing daily data on almost all areas of the earth. I first read about the Planet Dove program in the March 2018 issue of National Geographic. The data that I downloaded during the 14-day trial period is impressive with four bands and 3m spatial resolution. I am using the data for projects that we have to map Colombo’s wetlands. You can acquire premium commercial Digital Globe imagery at 30-70cm cm spatial resolution but it is expensive and I have not yet been able to get educational discounts through our local provider. I am working on getting an evaluation sample but for the moment this will be out of reach for most school geography programs. You can browse recent Digital Globe imagery here and of course they provide much of the imagery that you see when you zoom in on Google Earth. The European Space Agency’s (ESA) Sentinel 2 satellites (through the Copernicus program) provides an excellent public service of earthy imagery that compliments what USGS and NASA have been providing. I find the best way to access Sentinel data is through the USGS’s EarthExplorer
  • Field Data Gathering With Mobile Apps: The development of mobile data gathering platforms has been a significant boon for geography and science teachers looking to collect survey data and then to enhance it with locational information. The December post highlighted how we are using Survey 123 here at OSC.
  • Mapping With Drones: Most international schools have drones as part of their maker spaces or technology departments. OSC has two that are beginning to be used, mainly for providing cool aerial perspectives of the campus and special events. I am working on using our drone to map the campus and other key study areas (wetlands, forest areas etc.). At the recently concluded GIS Users Conference I was impressed with a real-time demonstration by a Ministry of Defense R&D team to map a small area. I am working with the OSC tech team to get Drone Deploy (to pre-establish the flight path and order of images taken) and Drone2Map to create the orthomosaic or 3D model of the area.

PAST GIS BLOG POSTS

Written by ianlockwood

2018-03-27 at 8:33 pm

GIS Developments at OSC in 2017

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GIS as a tool for teaching and learning in the DP Geography program (the field, Survey Department and in a final Geography EE map).

November 15th marked GIS Day, a time set aside to recognize the important role of Geographical Information Systems (GIS) in our lives. With a theme of GIS as the “science of where” it seems like a good time to look at ways in which we are using GIS as a tool for teaching and learning at OSC. Ten years ago, I put in the first proposals to adopt a GIS program at OSC as a part of our MYP and DP Geography courses. Since then the school’s small program has grown steadily while there have also been enormous leaps in the technology. This post reviews the newer applications and data sources that I am using as a tool for geospatial teaching and learning in the OSC environment.

Curricular Links in the International Baccalaureate DP

As far as I know, there are no explicit requirements that GIS skills be taught in any IB course. There are references made to GIS in the revised DP Geography, First Examinations May 2019 syllabus though they are not required (unfortunately, from my perspective). On page 19 it says “it is recognized that the ability to use GIS as a tool is a valuable geographic skill that goes beyond many of those listed below. Where GIS is accessible and practical, its use is encouraged.” Of course, there are many geographic skills listed in the guide that can be taught using a GIS platform. The Environmental Systems & Societies, First Examinations 2017 syllabus in the Investigating Ecosystems (2.5) section mentions GIS as a tool to use when tracking land use change (see p. 38).

At OSC I take time to teach several basic GIS lessons in DP Geography that allows students to use it as a tool for case studies and work on the internal assessment. In the past, I have worked with MYP students to introduce them to skills and methods for using our ArcGIS software. This year we are once again introducing GIS skills for MY 5 so that they can map spatial patterns from their Galle socio-economic survey work.

Survey Pan

Mobile Data Collection & Tracking

The advent of wide spread use of smartphones and improved 4G cellphone networks has opened up opportunities to use mobile data gathering apps on phones. There are a variety of options including open source apps (Open Data Kit, etc.). I am using ESRI’s Survey123 which comes with our ArcGIS site license. For the first time this year we recorded all of the DP Geography Sinharaja field surveys on Survey123. The class set up a common survey with questions about gender, housing, water access, land use and other variables. Before we went to the field we trialed a simpler version in Colombo. In the field, every student had a phone but we also backed it up with paper copies. At times, there was no cell phone access. We were able to upload the data later when we had cell phone connectivity (this worked quite well although photographs attached to the survey slowed down the uploads considerably). It was a much better way to tabulate the data (there were more than 70 individual respondents in total) and the class could map the data points since each had a spatial reference.

At the same time, I have been experimenting with using phone apps to track and record hikes and trails that we walk on CAS experiences. Strava, a fitness oriented app, offers an excellent way to record tracks. I am exporting GPX trails and then putting them onto Google my maps and sharing them with participants. I’ve taught students how to use them as a way to record key paths on their CAS blogs (see Maha’s Off the Grid post or my Mannar account for an example of this). We are currently using Google My Maps for this and layering the GPX trails onto a map that we make public. I would like to use an Openstreetmap for the base layer but this requires a WordPress plugin and $$$.

Hardware & Online Software

In terms of hardware we are operating a basic system with a server/desktop and then four lab desktops (each with decent specs-16 GB RAM, fast processors, graphics cards, large (2tb) drives and wide HD monitors. Geography students have access to ArcGIS Online on their laptops (both OSC and Windows platforms). When it comes to working with imagery I find it easier to use the desktops where I have spatial data stored for specific class assignments.

There are a variety of software options for using GIS as an educational tool. The most widely used open source GIS software package must surely be QGIS. It has an OSX version and the interface is quite similar to ArcGIS. At the school we continue to use the industry-standard, proprietary ArcGIS group of applications and have maintained an advanced license for over the last eight years through GIS Solutions here in Colombo. I am able to get technical advice from IWMI’s GIS lab when there are new operations or application that we want to put to test. I have also developed relationships with other major GIS users who are working on environmental issues in Sri Lanka.

Openstreet Map Contributions

In the last two years we have been using Openstreet Maps and have made minor contributions in our neighborhood and areas of interest. I value the idea of an open platform wiki space where users can contribute spatial knowledge. It is also an excellent source for downloading shapefiles of houses, building, roads, and other features in our Sri Lankan study areas. This data is often more update to shapefiles that are commercially available. We have had students download OSM data and then use the shape files to design studies of land use in the Colombo CBD (see attached image).

Recent OSC Student GIS work

Support from Local Contacts

OSC’s GIS initiatives continue to enjoy support for several key Colombo-based players. The International Water Management Institute’s (IWMI) GIS lab has been our main resource. They provide us with technical guidance and share public data that can be used for student learning. Their Water Data Portal is an important source of publically available spatial data.

Dr. Ajith Gunawadena at the Central Environment Authority’s Research and Development (GIS) unit  has become a good friend. He has helped me understand the ways in which the CEA and other government agencies are using GIS to tackle a range of national challenges. He helped guide the production of district level spatial databases (resource profiles).

I have developed good relations at the Sri Lankan Forest Department. Their GIS unit is working on updating the forestry map of Sri Lanka (last completed in 2010) and I have had a chance to see how they are using remoted sensed imagery to inventory different types of forest cover. The best way to access their basic forest data is on the FAO-sponsored REDD+ National Forest Monitory System portal. At the invitation of Anura Sathurasinghe, several of our DP2 students and I participated in the recently held 27th Asia Pacific Forestry Commission meetings here in Colombo.

Colombo is now growing rapidly and this has given students an opportunity to study process of urbanization and urban environments first hand. The port city project, still controversial but speeding ahead, is moving at a rapid pace. While the Urban Development Authority used to be the key agency for getting urban data, the Western Region Megapolis Planning Project  now seems to be the main agency with data and information about Colombo’s urban projects. Master plans are available on their website for download.

SL Survey Department Developments

The Sri Lankan Survey Department continues to be a remarkable government agency that supports geographic teaching and learning in the country. I have always appreciated their open view to public access to maps and spatial data. At the GIS Day 2017 event several of their team members spoke about developments at the SLSD. Sarath Jayatilaka and N. Wijeyanayake, traced the historical development of mapping at the department. Mr. Sivanantharajah bought the audience up to date with new developments in remote sensing including the use of lidar to generate highly accurate elevation models. The Survey Department is at work on a National Spatial Data Infrastructure (NSDI) platform but this is expected to be another six months or a year before it is unveiled to the public. Meanwhile some of their maps and data can be viewed on an interactive portal and their land information system. What would be nice is if Sri Lanka’s larger neighbors would be willing to learn from the island nation’s open approach to making spatial data and maps available to the public to improve overall geographic knowledge and understanding!

Accessing Population, Development, Environmental, Energy & Poverty Data

When addressing core concepts of the Geography and ES&S syllabi there are now an amazing variety of map-based data portals to access up-to-date statistical data.

  • I have been using the Washington DC-based Population Reference Bureau data tables to study and analyze population patterns for nearly 20 years in my teaching and they now are accompanied by interactive map portal.
  • World Resources is sponsoring a useful Data portal on deforestation called the Global Forest Watch. Their data is built on a Google Earth Engine
  • World Bank data, a leading source of data on economic development and poverty, can be found on their data portal. DP1 students made an important discovery when they accessed the Interactive Bangladesh Map. We were able to download the GIS-ready data and then view and manipulate it in an ArcGIS environment. I understand that they will be doing similar sites for country and global data.
  • For data on the Himalayan region ICMOD maintains the Mountain Geoportal.
  • The Sri Lanka Census & Statistics department has always been a good source of data. They now have an interactive geoportal to access some of this data. It is layered on an Openstreet base map.

PAST GIS BLOG POSTS

REFERENCES FOR GIS TEACHING & LEARNING (2017 Update)

Bolstad, Paul. GIS Fundamentals: A First Text on Geographic Information Systems, Fifth Edition. Acton, MA,Xanedu, 2016. Print. Web Resource Link, (GIS lessons).

Brown, Clint and Christian Harder Eds. The ArcGIS Imagery Book: New View. New Vision. Redlands, CA: ESRI Press. 2016. Print (Web version).

ESRI. Advancing STEM Education with GIS. Redlands, CA. 2012.   Web.

ESRI. K-12 Education portal. Web.

Harder, Christian and Clint Brown, Eds. The ArcGIS Book, 2nd Edition. Redlands, CA: ESRI Press. 2017. WebPDF.

Jensen, John R. Introductory Digital Image Processing: A Remote Sensing Perspective, 4th Edition. Glenview, IL: Pearson GIS, 2016. Print.

Keranen, Kathyrn & Lyn Malone. Instructional Guide for the ArcGIS Book. Redlands, CA: ESRI Press, 2016. Print (Web version).

Kimerling, A. Jon. et al. Map Use, Eighth Edition. Redlands, ESRI Press, 2016. Print. Web Link. Review by Daniel G. Cole.

O’ Connor, Peter. GIS for A-level geography. Geographical Association/ESRI, 2008. Print.

Written by ianlockwood

2017-12-01 at 11:39 pm

Mapping Montane Grasslands in the Palani Hills

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Remnants of a pine tree that had invaded a patch of remote grasslands and then been ring-barked in 2013 as a part of an effort to protect the last vestiges of native montane grasslands in the remote Palani Hills. In the background the undulating hills leading back to Berijam and Kodaikanal have been thickly forested with non-native plantation species.

Remnants of a pine tree that had invaded a patch of remote grasslands and then been ring-barked in 2012 as a part of an effort to protect the last vestiges of native montane grasslands in the remote Palani Hills. In the background the undulating hills leading back to Berijam and Kodaikanal have been thickly forested with non-native plantation species.

Over the last year a group of scientists, conservationists, photographers and citizens have been working on a unique collaborative project to document and map the remaining grasslands of the Palani Hills. Montane grassland and shola habitats are a distinct feature of the upper Western Ghats and have been the focus of my personal explorations, writing and photography of/about  the area. The grasslands mapping project, supported by INTACH,  seeks to quantify the change in montane grasslands and draw attention to areas that can be restored. Robin Vijayan, now on faculty at the Indian Institute of Science Education and Research (IISERT,) in Tirupati is the coordinator. Other key stakeholders are associated with ATREE, NCBS and the Kodaikanal-based Vattakanal Conservation Trust. The Tamil Nadu Forest Department is a key partner and will be able to use the results to better plan restoration and management in the newly gazetted Kodaikanal Wildlife Sanctuary. Regular readers of this space will see that there are familiar themes highlighted in past posts, notably the post on the plantations symposium in December 2014 and the “preliminary visual assessment” post from April that year. This post highlights efforts of the group and a visit to the southern escarpment to ground truth areas that had been mapped with satellite data.

Inspecting a plot of cleared plantation on the road to Berijam Lake. The idea was to restore grasslands by clearing plantation. This has proven very difficult, if not impossible to achieve despite the best intentions. Cleared plantation areas soon become infested with weeds and wattle seedlings. In this image, pioneer Daphniphyllum neilgherrense trees are visible amongst the debris of the cleared wattle plantation. These pioneer shola species came up amongst the wattle that had been planted on grasslands. Thus, what emerges in plots that are located close to mother sholas is a hybrid plantation-shola mix in what was once montane grasslands. Examples like this illustrate the challenge and complexity of shola/grassland restoration in the southern Western Ghats.

Inspecting a plot of cleared plantation on the road to Berijam Lake. The idea was to restore grasslands by clearing plantation. This has proven very difficult, if not impossible to achieve despite the best intentions. Cleared plantation areas soon become infested with weeds and wattle seedlings. In this image, pioneer Daphniphyllum neilgherrense trees are visible amongst the debris of the cleared wattle plantation. These pioneer shola species came up amongst the wattle that had been planted on grasslands. Thus, what emerges in plots that are located close to mother sholas is a hybrid plantation-shola mix in what was once montane grasslands. Examples like this illustrate the challenge and complexity of shola/grassland restoration in the southern Western Ghats.

In July I had a chance to participate in a four-day survey of montane grasslands in the remote Palani Hills as part of the grasslands mapping project. For several months of this year the grasslands mapping project has employed two young and energetic GIS/RS technicians Arasu and Danish. They have been systematically classifying the Landsat data from 1973 and 2014 and then “ground truthing” land cover across the Palani Hills. The result has been a series of computer-based maps and data sets that show historical grassland compared to their current extent. It is an unprecedented enterprise in the Palanis and the results are startling. The data and maps will eventually be available for key stakeholders and the wider public once there has been a rigorous review process.

Danish and Arasu had ground truthed most of the upper Palanis Hills areas by June but the high plateau between Berijam and Vandaarvu was un-surveyed due to strict permissions regarding access to this core area of the sanctuary. It is an area that I have been visiting on and off since I was a student at Kodaikanal International School in the early 1980s –thus my role was to guide the group to some of the key places where there are still grasslands. We were joined by National Geographic explorer Prasenjeet Yadav who has been contributing his time and photographic talents to document the themes of the project.

The Berijam to Vandaravu area has experienced significant change as grasslands have been replaced with non-native plantations during the last 40 years. In the last two decades I have been more systematically documenting landscapes and key aspects of the ecology in the Palanis Hills and wider Western Ghats. Land cover changes are a particular interest brought about by personal experience (several generations of our family have explored the ranges). I have traditionally used a camera to document observations but increasingly I have been turning to remotely sensed images that can be used to monitor and measure land cover change.

Danesh taking data points at a rare grasslands patch on the way up to Ibex Peak. Behind stretches a view to Berijam and beyond-now all under thick forest cover.

From top left to bottom right: Danish taking data points at a rare grasslands patch on the way up to Ibex Peak. Behind stretches a view to Manavanur and beyond-now all under thick forest cover. Close up views of Mapit logging attributes and getting a GPS point.

From top left to bottom right: Cutting through fallen pine trees on the road to Katrikodai from Berijam. Prasen inspecting steep slopes and remnant grasslands at Prayer Point near Marion Shola. Danesh with forest guards logging a point on Mapit.

From top right to bottom left: Cutting through fallen pine trees on the road to Katrikodai from Berijam. Prasen inspecting steep slopes and remnant grasslands at Prayer Point near Marion Shola. Danish with forest guards logging a point on Mapit.

The visit to Kathcikiriodai and Ibex Peak in July gave our small party a good sense of how little natural grasslands are left in the Palani Hills while also appreciating the complexities that the plantation ecology have brought about. Initially we were delayed by fallen pine trees on the road (the old Kodai-Cochin road) and our team had to spend the night at the Berijam FD bungalow. On the second day Bob & Tanya drove us up to the road blocks and then we trekked into Kathcikiriodai. On our walk to Kathcikiriodai it occurred to me that there are only two types of grasslands surviving in this area: marsh grasslands and patches of non-native grasses growing on areas that used to be coop camps for woodcutters (when the area was actively logged). Otherwise everything else is plantation with virtually no shola (Marion Shola has a healthy shola and there must be a few others away from the road).

Grassy patch of non native grass species in an area that was once a coop shed where Sri Lankan repatriates worked to plant and harvest non-native timber species. I have memories of walking by remote, squalid camps in the 1980s during our hiking program.

Patch of non-native grass species in an area that was once a coop shed where Sri Lankan repatriates lived while working to plant and harvest timber species. I have memories of walking by remote, squalid camps in the 1980s during our school’s hiking program.

Forest guards taking out a young pine tree invading cliff side grasslands near Ibex Peak.

On the afternoon of Day 2 we visited Marion Shola, its dilapidated bungalow and the nearby cliffs. There had been a fire on the cliff edge-formerly grasslands abut now invaded with mostly eucalyptus. We revisited the site on the last day and were able to get a much better sense of the habitat, land use and awesome cliffs. We spotted a small herd of Nilgiri tahr (in close proximity to a bonnet macaque troop) several hundred meters below us. We appreciated the significant montane grasslands that crown the Agamalai range to the south – not in our study as they fall in the Theni district.

We had our most significant day on Tuesday July 19th when we trekked with four forest guards out to the Ibex Peak cliffs. We were blessed with sunshine and clear weather for the first crucial hours of the trip. On the way we passed though a few native grasslands patches as well as areas where grasses coexisted under thin eucalyptus plantation (Danish mapped and photographed all of these). I was alarmed at the cliff edge where it seems to me the wattle and pine is making advances into the strip of 30m or so grasslands that was never originally planted. The 2013 restoration efforts were visible (dead, leafless pine, and trunks with rings). However, as Bob Stewart later reiterated, it can not be a single effort and more, regular work needs to be done if these last grasslands are going to be saved. We walked up to Ibex Peak (2, 517 m), explored the marsh below it, which is still in very good shape and then headed back to Kathcikiriodai a little after noon. By that time the whole cliff area was covered in mist.

Scenes of grasslands on the path to Ibex Peak showing varying levels of invasion by non-native timber plantations.

Scenes of grasslands on the path to Ibex Peak showing varying levels of invasion by non-native timber species.

Interestingly, we heard some of the key shola species as we walked through the plantations-White Bellied Blue Robin (Myiomela albiventris), Black and Orange Flycatcher (Ficedula nigrorufa), Nilgiri Wood Pigeon (Columba elphinstonii) and Kerala Laughing Thrush (Trochalopteron or Strophocincla fairbanki). There was a pair of Nilgiri pipits (Anthus nilghiriensis) at Kathcikiriodai -apparently content amongst the non-native grasses and remnant marsh habitat. We photographed two different shrub frogs, found a Salea sp. (most likely anamallayana) in the burnt out eucalyptus and came across a shieldtail on the walk out (near one of the coop patches). The only gaur we saw was a herd from near Ibex Peak. There was significant elephant dropping evidence along the roads.

The four forest guards provided important support to our group and I gained a new appreciation for their role. Two accompanied us from Berijam and another two were based at Kathcikiriodai. They are clued into restoration and removed pine saplings from our path to Ibex Peak (at least one of them had worked with VCT on the cliff restoration initiative four years ago). They are however not well supported and have minimal equipment. They had no working wireless and with no cell phone connectivity and they are completely on their own! After trekking with forest guards and staff in other PAs in south India I feel that much more could be done for these men and their important work.

At the escarpment edge just east of Ibex Peak, the 2nd highest peak in the Palani Hills. These are the crucial grasslands that have been identified to be saved from encroaching invasive species. Our survey found them still intact but under pressure as pine, wattle and even eucalyptus spread beyond their original plantation boundaries.

At the escarpment edge just east of Ibex Peak, the 2nd highest peak in the Palani Hills. These are the crucial grasslands that have been identified to be saved from encroaching invasive species. Our survey found them still intact but under pressure as pine, wattle and even eucalyptus spread beyond their original plantation boundaries.

We made several important observations over the course of our survey:

  • Almost all the plateau’s montane grasslands area from Berijam to Vandaravu was planted with non-native timber plantations species in the last 40 years. This is supported by satellite evidence and terrestrial photographs from the 1960s and 70s. There are virtually no unplanted grasslands areas unless they contained shola or the soil was too thin.
  • There are several small grasslands patches on the road to Kathcikiriodai and Marion Shola. Remembering experiences from my school hiking days I am reminded that these are former coop shed camps that housed labor (often Sri Lankan repatriates) planting and harvesting timber. The patches do not support native grasslands but appear to provide fodder for herbivores (gaur, sambar).
  • Several large and medium-sized marshes in the area were left unplanted (for obvious reasons). These still exist, though there is some invasions of pine. One large marsh (10.168704° N, 77.366623°E) was dammed to provide drinking water (Konalar dam) for Poondi and Kavanji villages. Its lake now extends all the way to what used to be known as First Trout’s Stream.
  • Shola regeneration in the plantations between Berijam and Kathcikiriodai is extremely limited other than the beginning where plantations adjoin the Temple Shola near the Berijam FD camp. It illustrates the apparent fact that without a “mother shola” there is limited spread into plantations.
  • Plantations appear to have been planted to approximately 30 meters of the escarpment edge (a very abrupt border). These edges once supported remnant montane grasslands and were important for Nilgiri tahr and other herbivore populations. However, most of these edges have now been invaded by plantation species. The Ibex Peak cliff to Ullam Pari grasslands are some of the last remaining patches but these are experiencing invasion (see photos).
  • The May 2012 restoration work by VCT arrested some of this invasion in a limited area. However, it needs to be a regular intervention if these critical grasslands are to be saved from being overtaken by plantation trees.

In conclusion, I want to put in a special word of thanks to VCT for organizing the permissions and the drop off and pick up. My colleagues Prasen and Danish were excellent company. We are grateful to the TN Forest Department for facilitating the survey and providing us with the guards and accommodation at Kathcikiriodai. I am looking forward to making further contributions to the project and effort to protect this part of the Western Ghats.

The maps that are referred to earlier, as well as my own tinkering with spatial data, will be shared in a future post.

 

PAST BLOG POSTS & PUBLICATIONS

Lockwood, Ian. “Recent Publications.” Ian Lockwood Blog. 11 November 2015. Web.

“         “Forest Plantations and Biodiversity Conservation: A Symposium in the Palani Hills.” Ian Lockwood Blog. December 2014. Web.

“         “Land Cover Changes in the Palani Hills: A Preliminary Visual Assessment.” Ian Lockwood Blog. 4 April 2014. Web.

“         “Landscape and ecology in India’s Western Ghats: A Personal Odyssey.” Asian Geographic. July 2008. Print & Web.

“         “Restoring Montane Grasslands in the Palani Hills. Ian Lockwood Blog. July 2012. Web.

“         “On the southern rim of the Palani Hills (Part II). Ian Lockwood Blog. September 2011. Web.

“         “On the southern rim of the Palani Hills (Part 1). Ian Lockwood Blog. September 2011. Web.

Written by ianlockwood

2016-08-22 at 11:56 pm

GIS Developments at OSC in 2015

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Screen shots of a Storymap utilizing base layers from National Geographic with layers of spatial data from Sri Lankan sources. The bottom map utilizes the Stamen Water color tint and is also layered with a n urban areas layer sourced from IWMI.

Screen shots of a Storymap utilizing base layers from National Geographic, simple annotations and layers of vector data from Sri Lankan sources. The bottom map utilizes the Stamen Water color tint and is layered with an urban areas layer sourced from IWMI ( see the links to actual story in the text).

The GIS program at the Overseas School of Colombo continued to evolve and adapt to broader technological changes in the school and world in 2015. The most significant development has been the school’s move away from campus-based servers to cloud-based applications and online data.

For the past seven years we have been running a small, but robust, GIS introduction program for students using desktop applications on computers in common spaces such as the library. Instruction has been based on using ESRI’s ArcMap desktop applications that are bundled with extensions as part of an annually renewed license. This represents a significant investment of the school in the software, provided locally by GIS Solutions Pvt. Ltd. I have also explored using QGIS and regularly utilize Google Earth, MyMaps and other freely available software. At the moment I am the only teacher providing the skills so it has been difficult to get all classes on board but I have been evangelizing colleagues to get them to weave GIS into their science and humanities units. In the 2015-16 school year students had to have their own laptops as a part of a 1:1 tech program and most of the desktop computers were phased out. One clear benefit of this is that all students can access ArcGIS Online regardless of their platform (ArcMap desktop was never available for Macs). Loading the desktop software on multiple machines is cumbersome and so the online options save time and hassle. Necessity being the mother of invention, I have been adjusting many of the DP Geography exercises that I had developed on ArcMap desktop to ArcGIS Online. Bandwidth and Internet speed is still an issue and for my own mapping and remote sensing work I prefer to use ArcGIS desktop. In the last two years I have refined my cartography with maps on Sri Lanka’s Central Highlands, the southern Western Ghats and Landsat imagery over the Pune Sahyadris.

Screen shot of Maptia story on Kukkal (created in 2014).

Screen shot of Maptia story on Kukkal (created by the author in 2014). This is not a spatial platform but Maptia offers a dynamic way to share digital stories that emphasize fine photography.

New Opportunities in Digital Storytelling

One of the dynamic tools that has been introduced by ESRI alongside ArcGIS Online is StoryMaps. This online software allows users to create visual story lines that incorporate narratives, images, videos and maps. There are a variety of templates to set your Storymap up and you can utilize a treasure trove of online maps to illustrate your story. You can also load up your own spatial data and overlay this raster and vector data on the base maps to help tell a compelling story. Storymaps has excellent potential for teaching and learning and I have deployed it in the DP Geography classes to give students an alternative way to create case studies that are a key part of their course preparation ahead of the IB exams. To model this potential I have built a story around OSC’s Experiential Education program.

StoryMap table of contents showing layers and projects.

StoryMap table of contents showing layers and projects.

While story maps is ideal for sharing narratives that have spatial aspects there are other options for sharing visual narratives. Maptia is one free service that I have experimented with to tell a visual story. It offers impressive visual opportunities to share high quality images and a meaningful story. The numerous examples emphasize epic adventures and fine photography but could also serve as a vehicle for students to share learning from school trips and learning experiences. I used a story that I had written up about hiking in the Palanis for my first project entitled “Kukkal: Beyond the Last Ridge.” Maptia would be an ideal platform for students to share learning from experiential education – something I am trying to promote with colleagues at OSC.

ASB Unplugged Workshop

In February 2016 I will be giving a workshop at ASB Unplugged in Mumbai entitled “Geospatial Teaching & Learning: Opportunities, Applications, and Ideas.” The aim of this workshop is to help educators understand some of the developments and opportunities for geospatial learning in middle and high school programs. There will be some direct sharing of my experiences but will have hands-on opportunities to try out some of the free web-based applications. Here’s what I have written up in the workshop description:

In the last decade huge advances have been made with making remotely sensed (RS) images of the earth available to the public. Google Earth helped popularize and introduce Geographic Information Systems (GIS) to the wider public as a free web-based application. While GIS software once had a reputation for being both expensive and cumbersome to use, developments in commercial software (ESRI’s ArcGIS platform) and freeware such as Q-GIS now make it accessible to anyone interested. The cost of remotely sense imagery is now within reach of organizations and much of this is in the public realm. At the same time growing concerns about changes on the planet associated with rapid economic development have provided a real need for better analytical tools. GIS and remote sensing helps us to better understand and address these changes.

 International Schools are beginning to use GIS in their secondary school curricula following on the heels of North American schools that have geography standards that incorporate GIS (see AAG links below). Given the rapid change in software and hardware options it can be a daunting program to add on to a school’s already packed curriculum. GIS and RS offer ideal opportunities for inquiry-based, interdisciplinary learning in international schools settings.

 The workshop will highlight examples from the IB Middle Years and Diploma Programs. A unique part of the presentation will share details on developments in South Asia and ways that the Indian Space Research Organization (ISRO) is sharing data through its Bhuvan platform.

 

PAST GIS AT OSC Posts

 

REFERENCES FOR GIS TEACHING & LEARNING (2015 Update)

Clarke, Keith. Getting Started with Geographic Information Systems, 5th Edition. Upper Saddle River, Pearson Prentice Hall, 2011. Print. Companion website (password required)

Fox, Lawrence. Essential Earth Imaging for GIS. Redlands, CA: ESRI Press: 2015. Print.

Heywood, Ian, Sarah Cornelius and Steve Carver. An Introduction to Geographic Information Systems, 4th Edition. Essex,Pearson Prentice Hall, 2011. Print. Companion website. Instructor’s Resources.

Harder, Christian. The ArcGIS Book: 10 Big Ideas About Applying Geography to Your World. Redlands, CA: ESRI Press: 2015. Print & Web.

Horning, Ned et al. Remote Sensing for Ecology & Conservation. Oxford: Oxford University Press, 2010. Print.

GIS Geography. Web.

Jensen, John R. Remote Sensing of the Environment: An Earth Resource Perspective. Upper Saddle River, Pearson Prentice Hall, 2007. Print.

Kimerling, A. Jon. et al. Map Use, Seventh Edition. Redlands, ESRI Press, 2011. Print. Review of book.

Keranen, Kathryn and Robert Kolvoord. Using GIS and Remote Sensing: A Workbook. Redlands, CA: ESRI Press Academic, 2014. Print. Web link.

O’Connor, Peter. GIS for A-Level Geography. United Kingdom: ESRI UK & Geographical Association, 2008. Print.

Palmer, Anita et al. Mapping Our World Using GIS: Our World GIS Education. Redlands, ESRI Press, 2009. Print & Online Resources.

Written by ianlockwood

2016-01-12 at 10:54 pm

GIS Developments at OSC in 2014

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Colombo Area Landsat map.

Colombo Area Landsat map.

The teaching of Geographic Information Systems (GIS) skills is in the midst of completing its 5th year as a part of the secondary school curriculum at the Overseas School of Colombo (OSC). The program was launched in 2009 when the school (then under the leadership of OSC Head Laurie McClellan and Secondary Principal Oli Tooher Hancock) made an investment in licensed software from ESRI. Since then DP and MYP Geography classes have been exposed to basic skills and used GIS to support field work and studies at a variety of scales. Today students are exposed to GIS skills at an early stage through their Individuals and Societies (formerly Humanities) classes. We start in MYP 1 (Grade 6), have a unit in MYP 5 (Grade 10) and then use the skills in the DP Geography. Eventually I would like to see a full vertical scope and sequence of GIS skills throughout the whole MYP. The goal of these efforts is to support the MYP and DP curriculums and give the students additional skills that are transferable in a wide variety of disciplines and university study programs. GIS is a great tool for conceptual learning in the humanities and sciences – something that several examples in OSC’s MYP and DP programs highlight.

Using Google Earth Pro in the IB Diploma

Area and perimeter exercise using Google Earth Pro.

Area and perimeter exercise using Google Earth Pro.

For the past three years OSC has applied for and received the Google Education grant that has enabled us to access several licenses of Google Earth Pro. This has allowed us to perform several more advanced spatial processing jobs and to download higher resolution imagery of some of our study areas. A short exercise that we recently used Google Earth Pro for was to make an accurate calculation of the OSC campus perimeter and area on behalf of the MYP1 (Grade 6) Math and I&S classes. You can draw polygons in Google Earth but you need the ‘Pro” version to get an accurate measurement of the area and perimeter.

To make a comparison of the Google Earth Imagery and ArcMap’s free online “World Imagery” base layer I ran a comparison of the two methods. I imported the Google Earth polygon as a KMZ file into ArcGIS and overlaid it on the Global Imagery layer. This free web-based imagery is not nearly as detailed or up-to-date as the Google Earth imagery as the two contrasting maps show here (2nd image coming soon). There are slight differences in the estimated area and perimeter, presumably a result of differences in the Datum used in each of the maps.

ArcMap view of OSC

ArcMap view of OSC

MYP 1 and DP1 Collaborative Work

Creating a basic Sri Lanka map with GIS. Screen shots from a tutorial made in house for the MYP 1 class.

Creating a basic Sri Lanka map with GIS. Screen shots from a tutorial made in house for the MYP 1 class.

The MYP1 class is working on an introductory mapping Sri Lanka tutorial that I created with my wife Raina two years ago. The map that they create is built on SL Survey Department data and highlights a chosen Sri Lankan spatial theme (tourism, tea & spices, wildlife, heritage, beach locations etc.). This year it is a truly interdisciplinary project with a strong research component worked in and inputs from the IT department. Raina who teaches both of OSC’s Grade 6 Humanities (I&S) batches, has led the class though a research project cycle that has them investigating spatial themes in Sri Lanka. Initially they worked with the math department to better understand concepts of scale and area in maps (see above). Maria Jose, OSC’s tech integrator, is helping with guiding the students on how to use Adobe InDesign to create an illustrated booklet. I normally spend a block or two with each of the classes to help them learn the basic GIS skills that they will need to create a map focusing on the theme of their project.  This year my DP1 Geography students, fresh from their own GIS work on demographic patterns, helped to teach these classes. They used a short in-house booklet that takes them step-by-step through the project. We had the first collaborative sessions today and the results have been positive and gratifying. The older students demonstrated that they are caring and knowledgeable GIS instructors.

OSC's DP1 Geography students assisting and guiding MYP1 students with their first GIS assignment.

OSC’s DP1 Geography students Kai, Charlie and Arnold assisting and guiding MYP1 students with their first GIS assignment. Photo courtesy Raina Lockwood

 

DP Environmental Systems (ES&S) & GIS

Screen shots of reflectance booklet for OSC ES&S students.

Screen shots of reflectance booklet for OSC ES&S students.

The DP Environmental Systems students are using the ALTA II Spectrometer to look at the spectral signatures of a variety of surfaces. Spectrometry is a topic that has fascinated me since my father Merrick helped me build a spectroscope for a project in Hal Strom’s Grade 9 science class at AIS/D. At OSC students first used the ALTA II in a Group IV project in 2013. I have updated this as a full internal assessment practical related to ES&S 2.2 (investigating abiotic factors of an ecosystems). Part of the fun of this exercise has been creating a small tutorial/booklet on reflectance and how we can use remotely sensed data to study and analyze land cover patterns in space and time. The student work coincides my own investigations of spectral signatures and land cover data that can be derived from Landsat imagery. The opening image in this post is now in the midst of being taken apart and analyzed to detect patterns of reflectance that will help me understand, quantify and delineate land cover. I hope to transfer learning from the Colombo exercises to conservation sites such as Peak Wilderness, Sinharaja and locations in the Western Ghats. I am using Kathryn Keranen and Robert Kolvoord’s Using GIS and Remote Sensing workbook to guide me through the process.

OSC’s DP students choosing to do a Geography (or subject area) extended essay (EE) continue to use ArcGIS to create original maps to support their studies. Some of these are straightforward locational maps while others map health and demographic variables at a district levels (we can do it a district, or GN level if needed). There is untapped potential for OSC students to investigate GIS/RS options for future EEs and MYP Personal Projects.

Increasingly GIS is moving into cloud-based solutions. At the moment we don’t seem to have the bandwidth to use these options reliably. Instead OSC continues to rely on a server we have built up using data from a wide variety of sources. OSC enjoys a unique advantage in that several Colombo-based organizations where OSC parents work have dynamic GIS programs. Our school program has been able to benefit from professional guidance from these organizations and they have shared public spatial data for our students to use. At OSC we look forward to studying and helping students to address a variety of local and global issues using sate-of-the art geo-spatial tools. The software and data hat we are privileged to have access to has widespread application in a number of diverse fields. GIS and RS skills can be technically challenging to learn at first but OSC’s students have shown the ability to learn and apply the skills to analyze and address an array of global issues.

PAST GIS AT OSC Posts

REFERENCES FOR GIS TEACHING & LEARNING

Clarke, Keith. Getting Started with Geographic Information Systems, 5th Edition. Upper Saddle River, Pearson Prentice Hall, 2011. Print.Companion website (password required)

Heywood, Ian, Sarah Cornelius and Steve Carver. An Introduction to Geographic Information Systems, 4th Edition. Essex,Pearson Prentice Hall, 2011. Print. Companion website. Instructor’s Resources.

Horning, Ned et al. Remote Sensing for Ecology & Conservation. Oxford: Oxford University Press, 2010. Print.

Jensen, John R. Remote Sensing of the Environment: An Earth Resource Perspective. Upper Saddle River, Pearson Prentice Hall, 2007. Print.

Kimerling, A. Jon. et al. Map Use, Sixth Edition. Redlands, ESRI Press, 2009. Print. Review of book.

Keranen, Kathryn and Robert Kolvoord. Using GIS and Remote Sensing: A Workbook. Redlands, CA: ESRI Press Academic, 2014. Print. Web link.

O’Connor, Peter. GIS for A-Level Geography. United Kingdom: ESRI UK & Geographical Association, 2008. Print.

Palmer, Anita et al. Mapping Our World Using GIS: Our World GIS Education. Redlands, ESRI Press, 2009. Print.

Written by ianlockwood

2014-11-26 at 5:04 pm

Land Cover Changes in the Palani Hills: A Preliminary Visual Assessment

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1973 Landsat map of the high Range, Anaimalai and Palnis Hills.

1973 Landsat map of the High Range, Anaimalai and Palani Hills. (February 1973)

41 years later....Landsat view of the same area (February 2014)

41 years later….Landsat view of the same area (February 2014)

I continue to be interested in themes of change in the southern Western Ghats (and Sri Lanka) and am now working to better measure and detect land cover change using Geographic Information Systems (GIS) and temporal satellite data gathered by the USGS/NASA Landsat satellites. My interest in the area has grown out of a deeply personal engagement with the landscape over the last few decades. It started on childhood walks with my parents, was excited by explorations with friends in school and then developed in more systematic photo-documentation trips as an adult. In recent years teaching and family commitments have kept me from visiting the field as much as I would like. My interest in using GIS as a tool for teaching and learning has brought me back in touch with the Western Ghats, but this time through the lenses and sensors of distant earth observing satellites. In the last year I have been working with the latest Landsat 8 imagery and am thoroughly impressed with the quality of the imagery that is now publically available. This has led me to look back through NASA’S archives to find old imagery to conduct change detection with. This post highlights preliminary comparison of Landsat mages from 1973 and 2014.

The maps included in this post look at the block of the southern Western Ghats just below the Palghat gap where significant features illustrate momentous changes in the landscape over the last forty years. Both sets of images were collected in February, a time of the year when it is dry and there are cloud free days in the southern Western Ghats. The first image, however, was taken 42 years before the 2nd and thus offers a unique opportunity to compare the land cover changes in these hill areas. My particular interest here is the western plateau of the Palani Hills. This is an area that many generations of KIS students know well from the hiking program that took us to places like Vembadi Peak, Berijam Lake, Vandarvu and the Ibex Cliff area. Starting in the 1960s and 70s these areas experienced intensive silviculture based on the earlier designation of montane grasslands being “wastelands.” Few KIS students and faculty members appreciated that they were witness to a radical ecological reworking of the landscape. The net result has been a significant change in the ecology and landscape of the area. Vast areas of the shola/grasslands systems in the Vembadi-Berijam-Vandaravu area have experienced significant changes.

It is a complicated mosaic of vegetation, ecosystems and issues that is now in place on the upper plateau of the Palani Hills. As the 2014 Landsat 8 image illustrates, most of the Vembadi-Berijam-Vandaravu area is covered by non-native tree plantations but there are important sholas that thrive between them. Several invasive species are spreading beyond plantation boundaries and threaten the remnant grasslands. In some areas shola species are regenerating in and amongst non-native plantation species. Some feel that this will eventually give way to mixed forests of shola species and dying plantations. Logging of planation species has been largely curtailed though there is a move afoot in the Forest Department to remove exotic species. Much of the upper plateau area is of limits because of forestry rules that have sought to limit the impact of tourists and agricultural communities in the reserve forest (RS) zone. A Kodaikanal National Park is in the pipeline and its notification and boundary lines are expected in the near future. Nevertheless, human communities are pushing into outer areas as the township of Kodaikanal and its satellite communities expand. Gaur (Bos gaurus) populations are on the rise, felt mostly in urban areas rather than remote areas!

Looking south over the 2,000 meter high Eravikulam plateau from Kattu Malai. The sunrise highlights the extensive “downs” of the shola/grasslands complex that is uniquely preserved in this magical National Park. Anai Mudi’s distinctive hat profile is on the right horizon while the edges of the Palalni Hills are on the far left. My father Merrick and cousin Anna are at the edge taking in an unforgettable Western Ghats experience.

Looking south over the 2,000 meter high Eravikulam plateau from Kattu Malai. The sunrise highlights the extensive “downs” of the shola/grasslands complex that is uniquely preserved in this magical National Park. Anai Mudi’s distinctive hat profile is on the right horizon while the edges of the Palalni Hills are on the far left. My father Merrick and cousin Anna are at the edge taking in an unforgettable Western Ghats experience.

One feature that has remained relatively constant has been the shola/grasslands mosaic that makes up Kerala’s Eravikulam National Park and Tamil Nadu’s Grasshills (part of the Anaimalais Tiger Reserve). Comparing both the 1973 and 2014 maps shows that these areas of montane grasslands, interspersed with sholas, have stayed roughly the same. This perhaps is no accident since Eravikulam and Grasshills have both enjoyed protection in the midst of the flurry of tree planting in the adjoining ranges. The grasslands show up particularly well and contrast with the neighboring shola vegetation. This is most likely the result of winter frost that has dried out much of the exposed grass (and thus is not photosynthesizing).

Eravikulam will feature in a series of upcoming posts tentatively entitled the High Range Diaries but I have included a few images from my visits and explorations of the area in the 1990s.

View of Anai-Mudi & the Eravikulam plateau from the east. Scanned from 35mm color negatives.

View of Anai-Mudi & the Eravikulam plateau from the east. Note how the lowland tropical rainforest has been cut back to make room for tea estates. Anai-Mudi is on the left and the sheer granite cliffs that protect the park are obvious. These same cliffs provide a home for the most secure population of Nilgiri tahr. This was taken with my friend Rahul Madura on an Enfield tour of the area. Scanned from two 35mm color negatives. (December 1994)

Pine plantation in the Palani Hills near to Poondi.

Pine plantation in the Palani Hills near to Poondi.

The classic tourist view: looking west over Berijam Lake from the fire tower view point. In this image, the arm of Mathikettan Shola is clearly distinguishable from the uniform, tall eucalyptus plantation (extreme left and right). These trees were planted on montane grasslands in the 1960s and 70s in a program to increase biomass for fuel and tanning purposes. With the exiting Landsat imagery it is difficult to distinguish shola patches from such evergreen plantations. This makes accurate classification at this sale challenging. In the future, as the resolution of the satellite imagery improves, remotely sensed multi-spectral imagery should be able to make this distinction.

The classic tourist view: looking west over Berijam Lake from the fire tower view point. In this image, the arm of Mathikettan Shola is clearly distinguishable from the uniform, tall eucalyptus plantation (extreme left and right). These trees were planted on montane grasslands in the 1960s and 70s in a program to increase biomass for fuel and tanning purposes. With the existing Landsat imagery it is difficult to distinguish shola patches from such evergreen plantations. This makes accurate classification at this sale challenging. In the future, as the resolution of the satellite imagery improves, remotely sensed multi-spectral imagery should be able to make this distinction.

Index map for hill ranges of the southern Western Ghats using recent Landsat 8 multi spectral imagery.

Index map for hill ranges of the southern Western Ghats using recent Landsat 8 multi spectral imagery.

FURTHER REFERENCES

Be sure to read Farshid Ahrestani’s article “To cut or not to cut” published by Conservation India last month. It looks at the dilemma of what to do with the huge amount of non-native tree plantation biomass in the Palanis and other Western Ghats ranges. We visited Eravikulam together, through the good offices of KN Chengappa and Tata Tea, in 1993 and continue to share a passion for conservation issues in the Palanis and neighboring ranges. One of ours tasks is to collect historical imagery of the hill ranges and use these to cross reference with contemporary imagery to illustrate change at a terrestrial level (as is done in his article).

For information about interpreting false color satellite imagery, see Hollis Riebeek’s excellent article on the Earth Observatory website.

SCHOLARLY  (and  TECHNICAL) ARTICLES

Amaranth, Giriraj et. al. “Diagnostic analysis of conservation zones using remote sensing and GIS techniques in wet evergreen forests of the Western Ghats – An ecological hotspot, Tamil Nadu, India.” Biodiversity and Conservation. 12. 2331-1359, 2003. Print.

Joshi, Kumar P.K. “Vegetation cover mapping in India using multi-temporal IRS Wide Field Sensor (WiFS) data.” Remote Sensing of Environment. Volume 103 Issue 2. 30 July 2006. Web.2 April 2014.

Menon, Shally and Kamal Bawa. “Applications of Geographic Information Systems, Remote-Sensing, and a Landscape Ecology Approach to Biodiversity Conservation in the Western Ghats. Current Science. 73.2 (1997): 134-145.  Web. 30 March 2014.

Nagendra, Harini and Ghate Utkarsh. “ Landscape ecological planning through a multi-scale characterization of patterns: Studies in the Western Ghats, South India. Environmental Monitoring and Assessment.  2003. Web. 30 March 2014.

Nagi, Rajinder.  “Using the Landsat image services to study land cover change over time.” ARCGIS Resources. 13 May 2011. Web.

Prakasam, C. “Land use and land cover change detection through remote sensing approach:  A case study of Kodaikanal taluk, Tamil Nadu.” International Journal of Geomatics and Geosciences. Vol 1, No 2, 2010. Web. 30 March 2014.

Using Remote Sensing Imagery for Teaching & Learning in the IB

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Colombo Landsat#1

Colombo Landsat#1 (5,4,3 “infrared” false color view)(27 June 2013)

Several developments in data accessibility and technology have helped launch a popular revolution in the use of remote sensing technology. The Landsat program run by NASA and the USGS has had a series of satellites orbing the earth since 1973 and has recently put its entire 40-year archive in the public domain. What this means is that students, teachers, scientists and citizens can now access detailed imagery of anywhere in the world to analyze vegetation, land cover and change. This has interesting implications for teachers and students in the International Baccalaureate Diploma program.

Remote Sensing (RS) and Geographic Information Systems (GIS) is not formally a part of any IB Diploma subjects. Anyone pursuing geography at the tertiary level will have to have GIS skills, but this has not been incorporated into the teaching requirements. The Geography, Environmental Systems & Societies and Physics courses, all have opportunities to use these technologies to address key concepts and learning outcomes. In DP Geography GIS is a useful tool in building geography skills (core 1.0) and the Urban Environments option. I teach basic GIS skills to all of our Geography students for them to use in the Internal Assessment as well as areas of the core syllabus (populations in transition etc.). We are also working in the OSC Humanities department to introduce basic GIS mapping skills at an early age. Despite GIS & RS only playing a minor role in the syllabus, they are showing up in final assessments. The May 2012 IBDP Geography exam question, for example, featured a Landsat image of urban growth and sprawl in the Pearl River delta taken from the NASA Earth Observatory.

Colombo Landsat #3

Colombo from Landsat 8 (6,5,4 “false color”)(27 June 2013)

Colombo from Landsat 7 (2000)

Colombo from Landsat 7 (2000)

Colombo Band combinations with Landsat 8

Colombo Band combinations with Landsat 8

This year we have acquired two Vernier ALTA II Reflectance Spectrometers. I was exposed to the use of these while at the JOSTI workshops at Thomas Jefferson School for Science & Technology last summer. A highlight for me -and I was the only participant – was taking the Remote Sensing workshop with Lisa Wu and Shawn Stickler. They run courses in Geosystems and Oceanography which both utilize GIS and RS applications. Students  at TJ are actively involved in the design and usage of their data gathering equipment. One of them had completed impressive work in the Chesapeake Bay interpreting temporal data using Landsat images combined with ground truthing trips.

The Alta II meters are relatively simple gadgets that measure the reflectance of different colors from a given surface. The meter operates by shining a small LED light (from Deep Blue up to Deep Red and Infrared).  A photo sensor records the amount of light bouncing back into the meter.  The value that the meter gives is then divided by the particular color’s wavelength (in nm) minus the “dark value” (value of meter when no color buttons are pushed). So it does take some simple division to actually arrive at the reflectance percentage once you have your readings. These can be graphed (see jack example blow) and then compared to standard values. I ran an initial trial using mango (Mangifera zeylanica) and jack (Artocarpus heterophyllus) tree leaves. The next week our Grade 12 students conducted a similar test on a variety of surfaces as a part of their IB Group IV project. Reflectance is quite consistent for various species but there would be variations based on the age of leaf (which is why I took values for two different jack tree leaves). NASA has a helpful online spectral calculator for looking at reflectance values of different species in North America.

What is interesting is to use the reflectance meter to corroborate or ground truth reflectance values of surfaces that are visible in the Landsat satellite imagery. The normalized differential vegetation index (NDVI) has also become a standard test run using RS images. It measures a value of vegetation in a given area and this can then be compared to the same area at other times. The Earth Observatory has a clear explanation of the NDVI index. India’s Aligarh Muslim University also has an excellent article on reflectance that is worth looking up.  In the coming months my students and I will be working to make clear linkages between Landsat imagery and the values that they are collecting in our area.

Vernier Reflectance Spectrometer with different surfaces (the sensor is underneath and the value on the screen is for the "dark value")

Vernier Alta II Reflectance Spectrometer with different surfaces (the sensor is underneath and the value on the screen is for the “dark value”)

Reflectance readings from two jack fruit leaves (one old and one new).

Reflectance readings from two jack fruit leaves (one old and one new).

OSC students collecting reflectance data on a traditional tile at the craft village

OSC students collecting reflectance data on a traditional tile at the craft village, The above image shows the meter over a mango leaf. The value is a dark value (here with considerable light pollution from outside).

If you are looking to access the Landsat Program the best point to start is the USGS Earth Explorer (this is better achieved using a browser enabled with Java). Earth Explorer has a wide range of spatial data available and it is worth exploring all the many different data sets. Another point to access basic spatial data from Landsat (without having to process it) is the Terralook site. You can also use the Glovis Site (that I had recommended in my post a year ago). When I am working with Landsat data I download full GeoTif files from Earth Explorer and then work with the different tiles using ArcCatalog and ArcView (Desktop). Having a fast Internet connection is essential for this. I have started a page on my Mango Wiki site to help my students access Landsat data and instructions that are available online. A very useful manual to have is Remote Sensing for Ecology and Conservation authored by Ned Horning and several others at the Center for Biodiversity & Conservation at the American Museum of Natural History. For a portfolio of images taken from space and clear explanation of the way satellites gather multi spectral data see Andrew Johnston’s Earth From Space (Smithsonian National Air and Space Museum, 2007). The Alta II reflectance spectrometer meter is available through Vernier in the US and comes with a manual of lessons plans. It does not plug into the Lab Quest devices that most science labs are using.

Written by ianlockwood

2013-08-26 at 4:05 pm