Bushfires Australia: Black Summer |Part 4 — Bushfires devastating effects on NSW air and water Quality

Unprecedented bushfires in eastern Australia turbocharged demands for the government to take far more proactive steps and measures to tackle climate change, whilst these bushfires rekindled an ideological fight over the science behind the blazes. One of the NSW bushfire inquiry concluded that climate change was a key factor in the devastating fires that ravaged the state in Dec 2019 — Jan 2020 and where the NSW bushfires vice versa further impacted the climate, hence going in vicious circles.

In part 4, as part of the assignment, I further decided to review, analyze and blog how specifically NSW’s weather, water temperatures, and air quality had been impacted because of bushfires 2019–2020 and wanted to share my analysis with the community.

1. NSW estuaries water has warmed up over the years.

Analysis_1: Increase in water temp over time?

Interpretation: The dataset for more than 150 estuaries at NSW reveals that there has been increasing in water temperature by more than

in the last decade (Figure C, 1a). This increase has been because of many other reasons, however, one of the top ones is bushfires. Since bushfires drastically impact and alter the entire dynamics of the eco-system leading to a cascade (Appendix) of disturbances within the environment that impacts water temperatures, air quality index, water quality (PH levels and Salinity — Appendix_Q3_step1_P1). These devastating changes consequently impact and lead to air pollution and poor water quality, which impacts both aquatic as well as wildlife to alarming levels.

figure,1(a): Estuaries water temperature (2007–2018)

Analysis_2: How has Black summer impacted estuary's water temperatures? (For analysis data available from some rivers is taken from data.nsw available for 2001–2018 and 2020)

Interpretation: Figure C, 1(b) indicates that an increase in water temperature has been observed particularly during NSW state was ravaged by the bushfires. Lagoons and rivers' temperatures have significantly increased as compared to creeks and lakes. This temperature increase will have far-reaching consequences on aquatic life if it keeps going up at the same rate.

Black Summer_2019: Changes in water temperatures do not provide any meaningful insight in the context of impact from bushfires in Figure C, 1(c) since much more data is needed to conduct detailed analysis to identify actual facts, trends, and patterns in the temperature variations over the years before a final conclusion is made. Additionally, the data available is limited to few estuaries only.

To determine the trend of increasing temperature for estuaries (2020), data is linked to 2001–2018 datasets and complete time series data for only two lakes was recovered. This upon analysis revealed that an increase in temperature of more than 2-degree Celsius has occurred in the last 10 years as shown in Figure C, 1(d).

FigureC,1(b): estuaries water temperature (Estuary_type)(2007–2018)

FigureC,1(c): Lakes water temperature (Black_summer)

FigureC,1(d): lakes water temperature (2001–2020)

1. Does Black_summer has any impact on pollutants?

The data for this analysis was taken from NSW government data for overall air quality, concentrations of Ozone and Carbon Monoxide, PM2.5 & PM10. Daily data was aggregated into monthly and yearly data.

Analysis_1: impacts on overall air quality?

Interpretation: The graphs were plotted for the years 2018–2019 to visually describe the impacts of bushfires_2019 on the environment. The graph in Figure C, 2(a) shows an increase in the air quality index. The very sharp rise and exponential increase can be observed from this figure from October 2019 with a sudden decrease after January 2020, with the highest recorded index of 5,004 µg/m3 on 31st Dec. This value was much higher than the hazardous level i.e. 200 µg/m3 as shown in Figure C, 2(a).

Figure C, 2(a): Air Quality-NSW (Black_summer)

Analysis_2: Are pollutants playing any role in increasing the air_quality index?

Interpretation: Figure C, 2(b) clearly shows an increase in CO, Ozone, PM2.5 & PM10 starting from summer 2019 and then upward trends. Particle size has also contributed significantly to the increase in the air quality index. Australia faced the worst air quality ever where it had been observed that black summer has the worst increase in the concentration of CO, Ozone, PM2.5 & PM10 in the last two decades (Appendix_Q3_Step2).

Some facts are as follows:

• Ozone: Average value is greater than 0.2ppm, more than 2 hours of exposure per day is considered hazardous.
• PM2.5: Monthly_average for Dec 2019 is 34 µg/m3, which is above the normal standards.
• PM10: Monthly_average for Dec 2019 is 60.78 µg/m3

Figure C, 2 (b): Air Quality- NSW (black summer: CO, Ozone, PM2.5, andPM10)

Read On:

Previous section: Part 3 — Research Question 2: Bushfires impacting Air Quality and damaging the land

Next section: Part 5 — Key Insights, Future Recommendations, and Conclusion

Reference:

Why Australia's 2019-2020 bushfire season was not normal, in three graphs

NSW Inquiry: Climate Change Fuelled Bushfires | Media Release | Climate Council

Water Quality:

Bushfires and water quality

Estuaries are warming at twice the rate of oceans and the atmosphere

Water in estuaries along NSW coast has warmed by more than 2C, study finds

Appendix:

Q3-Step 1:

P1: Change in Lakes water in NSW

Cascade of changes that occur to the ecosystem after a bushfire, impacting the natural habitat, water quality, water temperature, rise in climate temperature, disturbing the entire aquatic life.

Q3-Step 2:

P2: Air Quality