Cons 127 Observing the Earth from Space
Lab 5: Detecting Change with NDVI: Vegetation Responses through the Spectrum.
Total marks possible: 29
Instructor: Prof. Nicholas Coops
Office: FSC 2301
604 822 6452
TA: Dave Williams
Office: FSC 2232
For this assignment you will...
Learn about the spectral responses of vegetation
Learn how to calculate and utilize the Normalized Difference Vegetation Index (NDVI)
Be introduced to analyses of land cover, land use patterns, and land cover change
Explore how humans are impacting terrestrial ecosystems
Submit the following in a report:
Answers to questions 1 through 8. Brevity is much appreciated!
When answering these questions, you DO need to cite your references and put answers into
your own words. (2 marks)
This lab requires a computer with an internet connection, and the Java Web Application, which you used
in Lab 4 (but can be downloaded here). If Google Chrome is your default browser you’ll need to switch
to Internet Explorer if using Windows, or Safari if using a Mac OS. If you have any outstanding issues
running Java talk to the TA to set up a time to complete the lab on a Forestry computer.
Part 1: Interpreting Change using ESRI Change Matters
1. Understanding how Earth systems change through time, either due to natural or anthropogenic
processes (or both!), is an integral part of understanding how the world around us operates, how it
affects us, and how humanity impacts the natural world. With increasing data availability and
abundance, newer and better sensors and satellite constellations, and an increasingly long timeline
of observations, remote sensing scientists are well-positioned to detect change on the Earth at
many resolutions – in time, space and the EM spectrum. Satellite sensors provide consistent and
repeatable measurements of everything from whole-earth phenomena, like global primary
productivity maps derived from MODIS data, to sub-metre imagery of the trees lining city streets.
2. One common way of remotely sensing change on the Earth’s surface is by analyzing vegetation
through time – its spatial patterns and abundance, as well as its spectral properties. Because
vegetation reflects NIR wavelengths strongly (remember the red edge from lecture), remote sensing
scientists have developed vegetation indices, the most well-known of which is probably the
Normalized Difference Vegetation Index (NDVI), that take advantage of vegetation’s spectral
qualities. Using spectral vegetation indices we can directly and quantitatively compare remotely
sensed images. Vegetation indices also allow us to assess plant health and vigour, and can be
combined with other information to, for example, assess how surface temperatures are changing
due to the expansion of Indonesian oil palm plantations (Ramdani, Moffiet, & Hino, 2014), or study
how cities grow and change.
Q1. What is the formula for the NDVI (1)? Which Landsat bands are used to calculate the NDVI (1)?
3. In a web browser You’ll initially be
shown three false-colour images of Mount St. Helens: one in 1975, one in 2000, and one showing
the NDVI change between the first two images. To the top-right of the images is a “View Larger” link
that you might want to click, though note that it may cause the three images’ views to become