Assignment 4

 

Homework Assignment 4 (10%)

(a) Perform a Raster Merge on the four satellite images of FAS_China3.tiff, FAS_China4.tiff, FAS_China5.tiff and FAS_China6.tiff.

(b) Perform a Raster Extract covering the areas of the Taiwan Strait and Taiwan Island.

(c) Use the vector data for the boundaries of Taiwan's cities and counties.

(d) Display air pollution data for Oct and Nov (2012?), using Pseudocolor; Spectral (Blue to Red).

(e) Perform Raster Calculator to display the change of pollutants between those two months.
(f) Suggest some parts of Taiwan that are less hazardous to stay/live during those bad air quality days.

(a) Perform a Raster Merge on the four satellite images of FAS_China3.tiff, FAS_China4.tiff, FAS_China5.tiff and FAS_China6.tiff.

(b) Perform a Raster Extract covering the areas of the Taiwan Strait and Taiwan Island.

(c) Use the vector data for the boundaries of Taiwan's cities and counties.

(d) Display air pollution data for Oct and Nov (2012?), using Pseudocolor; Spectral (Blue to Red).

According to the Taiwan Air Quality Index from the Ministry of Environment of Taiwan, (https://airtw.moenv.gov.tw/CHT/Information/Standard/AirQualityIndicator.aspx) here are the classifications of air quality:

Here is a map for air pollution data in Oct:

Here is a map for air pollution data in Nov:

Here are the colours for representing different levels:

(e) Perform Raster Calculator to display the change of pollutants between those two months.

Here is the diagram calculating by using Nov-Oct:

However, by considering the larger the PM values, the outcomes of difference are larger as well. Therefore, I calculate the changes of PM value in percentage also. By calculating back in percentages, I set the scale in changes as <=10%, 10%-20%, 20%-30%, 30%-40%, 40%-60%, and >60%.

(f) Suggest some parts of Taiwan that are less hazardous to stay/live during those bad air quality days.

By using the Raster Calculator, for setting the PM value<=100, which is defined as 'Good' and 'Moderate' by the Ministry of Environment of Taiwan, here is the diagram for Oct:

Here is the diagram for Nov:

By taking reference of the two months, the orange parts in the diagram of Oct and the grey parts in the diagram of Nov are less hazardous to stay/live during those bad air quality days.