Ian Lockwood


GIS Developments at OSC in 2012

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Bangladesh Change Matters

Two sets of images from the ESRI/Landsat site called Change Matters. In both sets of pictures an early (1975) Landsat thermal/infrared image is compared with a more recent one (2000). The third image on the far right shows the NDVI, which give an estimate on vegetation change (either increases or decreases) during that time period. The above image set shows the Dhaka urban area while the bottom image details the beautiful waterways and mangrove forests of the Sunderban. I was living in Dhaka when both images were taken. One notable feature in the lower set is the birth of what is known as “Egg Island” in the south-east of the forest. It is not visible in 1975 but by 2000, a year that I last visited the area, the island has emerged. Today it continues to grow (see Google Earth image at the end of the post).

This year has seen a steady growth of Geographic Applications (GIS) in it usage to promote student learning in the humanities and environmental sciences at OSC. Some of this has been in the classroom, where a greater number of students are using GIS software to meet course expectations in the Internal Assessment and Extended Essay. A good deal of the growth in the last year has been in my own understanding of the myriad applications and data sources that are now available to users. I’ve become especially interested in remote sensing and the Landsat data archive that is now freely available. Perhaps the greatest development in GIS as a tool for teaching and learning in recent years has been the explosion of online applications and freely available data. This post will offer a short synopsis of these with the aim of providing an overview of teaching and learning options of GIS with a special focus on the South Asian region.

At OSC we continue to use the ArcGIS platform as our primary GIS software package. When I started up the program several years ago I was aided by several useful ESRI publications and online lesson plans from the ESRI Education Community. Notable amongst the books was the series Our World GIS Education (four volumes, first published in 2008). These are a bit dated now but the lessons and data still serve as a basis for the DP Geography study of population pyramids and the MYP study of the South Asian monsoon. Meanwhile the UK’s Geographical Association, in collaboration with ESRI, has published a book entitled GIS for A-Level Geography by Peter O’Connor (2010). This is probably the single, best volume to have for IBDP teachers looking to integrate GIS into their teaching. The examples and data are UK-based but it succinctly explains all the basics and has good examples. For a comprehensive introduction to maps and their applications the 6th Edition of Map Use  (A. Jon Kimerling et al 2009) is an invaluable resource. Further print resources that I have acquired to aid teaching of GIS are listed in my Wikipage.

Galle Fort Field Work

Snaps shots from the Galle MYP Geography/Humanities Field study.

Snap shots from the Galle MYP Geography/Humanities field study.

In the early parts of this year I designed a unit of study around the historical city of Galle on Sri Lanka’s South Western coast. It was part of a broader unit on globalization and tourism using Sri Lanka’s experience as a case study. We were interested to see to what extent land use patterns in the fort reflected evidence of a  development strategy that uses tourism to promote economic growth. The study involved designing and then conducing a series of surveys on a short field visit. Both Grade 10 MYP Humanities batches went down and spent a day conducting interviews to and gathering field data. Students mapped this using land use data from the Urban Development Authority. An example of what the students produced from the study is given below. The fort makes an excellent location for study; it is compact, free of traffic and is a safe location for students to wander around in. The new Southern Expressway makes the trip doable in one day- a perfect example of time-space convergence.

Student work on truism and land use in Galle Fort featuring the talents of Leila, Jesse and xx.

Student work on tourism and land use in Galle Fort featuring the talents of Leila, Jesse and Shubhanshu.

GIS Day at OSC

We celebrated “GIS Day” on November 15th with the support of the International Water Management Institute (IWMI). GIS Day, of course is a global event celebrated by organizations and educational institutions using GIS. The focus of our event this year was “using GIS to better understand, analyze and address climate change.” Salman Siddiqui the head the IWMIC GIS lab and I chose the topic based on some new work that IWMI is doing and the growing importance of understanding climate change and global warming that is evident in the IB Group III and IV curricula. Usign the OSC auditorium foyer we displayed a gallery of OSC student work and IWMI posters. GIS Solutions, lead by Thillai and Ramesh were on hand to talk about and promote different GIS software options here in Sri Lanka. The main event consisted of series of lectures that were aimed at a wide range of student ages. Salman gave the keynote lecture on how IMWI is using GIS to better understand and analyze climate change. The day was capped off with an interactive session in the library computer lab for participants. Juri Roy Bruman and Prunima Dehiwela brought a batch of Geography students from the British School and they helped give a broader perspective for options of using GIS in the IB/A-Level frameworks. Several OSC humanities and science classes joined the lectures and the turnout was healthy. Although we would liked to have invited more schools from Colombo, computer spaces for the interactive sessions limited this.

GIS Day 2012 Collage


In the August post I mentioned Bhuvan, the geo-spatial and earth observation portal from the Indian Space Research Organization (ISRO). With the support of IWMI’s GIS lab team I have learnt how to access some of its data and have been especially happy to be able to download a wealth of high-resolution tiles of remote sensing imagery. One of my first tasks was to learn how to use Web Map Service (WMS) links in ArcGIS and Q-GIS. This essentially allows you to import map data that is found on an online server into your GIS software and then combine it with shapefiles and raster data that you have in your own databases. Seems quite intuitive, but it was a revelation to actually succeed in combining the data. Bhuvan hosts a detailed land cover WMS file (see map below) and there are other data sets (floods, waste lands etc.).

SWG WMS (12 2012)

Land cover map of the southern Western Ghats with data provided by the Bhuvan land use/land cover (terrain) WMS. The 500 m contour was generated from an SRTM using ArcMap.

Bhuvan’s remote sensing data for India is of a high quality, but depending on what area you want it may not always be free of clouds & haze. You have several choices about data under the Thematic Services page where, with a simple login, you can download compressed files. These are unprocessed files with 4 tiles each and you need to process them like you would a Landsat file with multiple layers of multi-spectral imagery. It has been nearly six months since I processed Landsat files and I had to re-learn how to do this. I was aided by Jarlath O’Neil-Dunne of the University of Vermont’s very helpful online slide show. It turns out that the tiles of the Palani Hills area have excellent clarity and resolution. Other areas in the southern Western Ghats (High Range, KMTR, Nilgiris etc.) are not of the same quality. At this point they only have one tile per area for the 56m AWiFS imagery. That should change in the future.

Palanis with Bhuvan Images (12_12)

ESRI’s Change Matters is an easy to use website that allows you to look at early and late Landsat imagery as well as a NDVI images that map change in vegetation. It offers two Infrared views of areas with contrasting dates that are juxtaposed with the NDVI image. The comparison is startling especially when you look for signs of change in vegetation. In the Amazon it is the incredible loss of forest that is striking. Closer to home, the Palani Hills show an apparent increase in vegetation. However, as we all know that is because most of the native montane grasslands were replaced with fast-growing tree species such as eucalyptus during the last 20-40 years. In some places you need to be aware of seasonal changes in vegetation, say between the dry and monsoon seasons in South Asia. Clouds can also be represented as vegetation decreases so the data must be analyzed carefully to get a sense of change.


Another set of images courtesy of the ESRI/Landsat site Change Matters. This set illustrates changes in the Palani Hills and Highwavys. The addition of vegetation through introduced plantations in the upper Palanis is notable.

There are several new developments aiding data acquisition for GIS applications. Google has launched its Earth Engine, which is designed to be a portal for a mass collection of spatial data. NASA and the USGS are also working to consolidate their data under a new site called Reverb. This is where you will go in the future to mine the vast databases of  US government-funded spatial data repositories.

Egg Island (2011) Google Earth Image

A favorite place for birders and naturalists exploring the Sunderban in Bangladesh is “Egg Island.” The Guide Tours led by the Mansur family always took its visitors to Kotka and the area at the southern-eastern portion of the forest. What was once little more than a muddy bank at the point where the forest gave way to the Bay of Bengal was forming every year into a bigger, and bigger island. I first went there with birdwatchers Dave Johnson, Ronnie Halder, and Enam El Haque. Reading about their ongoing visits to the area makes me nostalgic for that wonderfully ethereal forest where I had so many memorable experiences. I continue to use it as an example of succession in a tropical forest. Unfortunately it has been hard to find time to return for an actual visit. The best I can do is view it through the lenses of satellites and the  Change Matters site has a fascinating look at the world’s largest mangrove forest. Egg Island wasn’t there in 1975 when the early passes of the Landsat satellites were made and Bangladesh was a newborn country. But the island had started to form in 2000 when we visited the area looking for Masked Finfoots, Rudy kingfishers, signs of Bengal tigers (we saw pug marks on the beach) and more…! Today it is growing into a larger island in spite of cyclones and sea level rise. This Google Earth images is from 2011.

Written by ianlockwood

2012-12-15 at 6:38 am

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