IS428 2018-19 Term1 Assign Aaron Poh Weixin

Background & Objectives

Air quality in Bulgaria is a big concern: measurements show that citizens all over the country breathe in air that is considered harmful to health. For example, concentrations of PM2.5 and PM10 are much higher than what the EU and the World Health Organization (WHO) have set to protect health.

Bulgaria had the highest PM2.5 concentrations of all EU-28 member states in urban areas over a three-year average. For PM10, Bulgaria is also leading on the top polluted countries with 77 μg/m3on the daily mean concentration (EU limit value is 50 μg/m3). According to the WHO, 60 percent of the urban population in Bulgaria is exposed to dangerous (unhealthy) levels of particulate matter (PM10).

The objective of this project is to first understand..... (continue)

Task 1: Spatio-temporal Analysis of Official Air Quality

Data Preparation

Before diving into the data cleaning process, it is important to detail some findings I got from simply observing and scanning the data.

• There are 5 air quality stations (9421, 9484, 9572, 9616, 9642), but 9484 only has data up to the year 2015
• Averaging format inconsistent across time periods
  • Year 2013-2015 averages data daily
  • Year 2016 mostly averages data daily, with some hourly averages
  • Year 2017 averages hourly. They also have a 'var' average which does not make sense
  • Year 2018 averages mostly hourly, with some daily averages

With this information in mind, I decided on the following cleaning procedure:

I will not be imputing any missing data, because I lack knowledge to decide what value would be suitable. Furthermore, the graph automatically draws a straight line from date with the last known value through the missing date to the next known date