Question 7: Qualitative Description of the data

[Descriptions of False Colour images]

In a false-color image, subject color and image color is different. This alternation can be happened in many ways.For example, the near infrared band (band 4 is projected onto colour film through a red filter (R), band 3 through a green filter, and band 2 through a blue filter. In this case, the red coloured area will represent VEGETATION, Black coloured area will represent WATER in false colour image.

Strong Reflectance in the green portion of the spectrum is represented as blue on the colour composite, red as green, and infrared as Red.Thus, living vegetation appears as bright red, turbid water as a blue colour, and urban areas as grey.

The reason why I provided this false colour image (I set band 4 as red, band 3 as green and band 2 as blue) is that I wanted to see how those two locations that has different latitude has different green vegetation areas. 

Map 1: False colour image of Eastern PEI

  latitude: 4.603171129914435e+01
      longitude: -6.217700231669508e+01

Map 2: False colour image of Auyuittuq National Park of Canada in Nunavut

latitude = 6.693539813327550e+01;
    longitude = -6.811795025302996e+01;

These two maps show areas that has very different latitude. Map 2 has larger latitude than Map 1, and this means that the area of Map 2 located in North.

As I can see those false colour maps above, Most of Eastern PEI is covered with vegetation with brighter Red. On the other hands, Map 2 shows less vegetation area with darker red colour. Dark red is typical of trees and thick shrubs; light red associates with grass cover. (http://rst.gsfc.nasa.gov/Intro/Part2_13.html#I-17)

Therefore, comparing two false colour images is helpful to understand:

1. How much area is covered by vegetation?

2. What types of vegetation we can see in the map?

[Description of NDVI images]

Map 1 :NDVI map of Eastern PEI

Map2 NDVI map of Auyuittuq National Park of Canada in Nunavut.

NDVI Maps Could not give a accurate representation about green vegetation area in two areas. Although such ratios have shown to be powerful tools for studying vegetation, it must be used with care if the values are to be rigorously (rather than qualitatively) interpreted. Values of ratios can be influenced by many factors expernal to the plant leaf, including viewing angle, soil background, and differences in row direction and spacing in the case of agricultural crops. (Campbell, J. B. 2007)

As we can see in Map 1 and Map 2, even though Map 1 has more vegetation area than Map 2, Map 2 has more green area. This was because NDVI could not differentiate each type of vegetation and and its quantity with just 4 classes. (when there was a little vegetation, the map represents as "vegetation")




I conclude that NDVI data is not useful to compare image from different regions that has very different weather that lead to have totally different types of vegetation (like thick shrubs vs. grass). 
 
I conclude that NDVI data might be useful to see change in plant growth and its productive in one given region in which there is a period of reduced or increased plant growth.
Observed over time, values of the NDVI depict a seasonal pattern of increase and decrease.

To see more information

See Question 2 & question 5
I added some explanations of data and steps in each question.