IS428 AY2019-20T1 Assign Sean Chai Shong Hee Q1
This section will answer questions for Mini Case 2
Question 1
Visualize radiation measurements over time from both static and mobile sensors to identify areas where radiation over background is detected. Characterize changes over time.
Visualising measurements from Static Sensors
Trends in measurements were easier seen when disaggregating the data. Radiation values for static sensors were plotted over time to show how measures varied over the span of 4 days from 6 April till 10 April.
The shapes indicate the radiation values taken at its respective neighbourhood. Highlighted in red are values that are higher than the average background cpm level, as determined by the Radiation Network to be 60 cpm.
We can see that there were very few values above 60 cpm recorded for 6th and 7th April. Almost all of the values recorded were well within the 60 cpm base background radiation level.
The next 3 days saw a big increase in recorded values above 60 cpm. Safe Town, where the radiation plant is located at, saw the biggest increase in number of recorded values above 60 cpm on the 8th of April, indicating radiation leakage due to an earthquake.
Old Town, which is situated adjacent to Safe Town, recorded large increases in the number of values above 60 cpm as well, indicating contamination by radiation leakage.
Visualising measurements from Mobile Sensors
There were significantly more records taken by mobile sensors over the 4 days. This, coupled with the fact that mobile sensors were not as accurately calibrated and powerful as the 9 professional static radiation monitors, led to high number of radiation values being more than 60 cpm.
On first observation, I realised there was an abnormally high radiation value at 57345 cpm in Old Town. This value was recorded on the 9th of April. While it might be indicative of a massive radiation leak, this value is not substantiated by the data collected by static sensor 9 in Old Town. I attribute this outlier to misreadings by the mobile device, and excluded it on the basis that it did not hold any significance.
Nevertheless, both data collected by static and mobile sensors in Old Town suggests that there was a spike in radiation levels on the 8th of April, which could indicate radiation leakage caused by the earthquake. Both visualisations for Old Town also suggests that radiation levels remained high from 8th - 10th April, as can be seen by the high number of radiation values above 60 cpm.
Upon removing the outlier, we can see a cluster of high radiation values on the 9th and 10th of April. This might be the result of radiation contamination being spread throughout the city of St. Himark. There is a general trend across all neighbourhoods where radiation values above 60 cpm is more prevalent on the 10th of April.
On closer inspection, we can see that a high number of radiation values above 60 cpm were recorded in East Parton, Safe Town, Scenic Vista and Wilson Forest. These are the highly contaminated areas which officials should look into.
