Becky Britton & Kim Quach
Cyclone Yasi
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Cyclone Yasi began as a tropical low to the northwest of Fiji, on the 29th January
2011 and began directing westward toward Australia
Cyclone Yasi hit the North-East coast of Queensland in the early morning of
February 3rd 2011, where it also became a category 5 cyclone. Yasi Targeted many
cities along the coast and slightly inland, Innisfail being one of the many.
The cyclone finally weakened at around 10:00PM near Mount Isa on the 3rd
February 2011 .
Yasi is one of the most disastrous and powerful cyclones ever to have hit
Queensland since records began, as evident in the astounding impact it made to
Innisfail’s rainfall in early February 2011
We have based our research on the
information of
http://www.bom.gov.au/climate/data/
Voronoi Graph Development
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We decided to use the method of a Voronoi Graph, or
Thiessen Polygon as referred to with climate, to
display our research
We found a map of our region where the cyclone hit
(Innisfail) to base our graph upon
All the nearest rainfall gauges to our region were
located and connected to their nearest neighbouring
gauges, forming triangular figures
We then identified the half way point of each line and
drew a perpendicular line through
The perpendicular bisectors were constructed and
joined to form our regions
Voronoi Graph Completed
Russel
River
Nerada
Alert
Daradgee
Tung Oil
Alert
Corsis
Alert
Innisfail
Marco
Street
Alert
Central
Mill TM
Mean of Feb 2011: 32.46ml
Median of Feb 2011: 7.5ml
South Johnstone
Exp Stn
Jan 15 – Feb 15 2011, Innisfail QLD
200
180
160
Millilitres
140
120
100
80
The horizontal blue lines across the graph
display the mean and median rainfall
measurements of the Innisfail Queensland
water gauge from Jan 15 – Feb 15 2011
These graphs present
the numerical values
we gathered from
www.bom.gov.au
We can observe that Cyclone Yasi hit
Innisfail around the time of Feb 3rd and 4th
and we can see the unnatural impact it
caused toward Innisfail’s rainfall levels.
60
40
Mean
20
Median
0
Jan Jan Jan Jan Jan Jan Jan Jan Jan Feb Feb Feb Feb Feb Feb Feb
15th 17th 19th 21st 23rd 25th 27th 29th 31st 2nd 4th 6th 8th 10th 12th 14th
Daily Rainfall
February Rainfalls, Innisfail QLD
1200
1000
Millilitres
800
In the past 13 years, 2011, the year
of Cyclone Yasi, holds the third
highest level of February rainfall.
Innisfail has also experienced
such occasions before, as seen in
2007 and 2009.
600
400
200
0
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
February Total
Monthly Rainfalls, Innisfail QLD
1000
900
800
Millilitres
700
This graph compares the total, mean and median rainfall of
each month over the time period of 2000-2013. The total
rainfall levels are the sum of all the measurements, the mean
being the average and the median, the middle of the results.
2011 definitely stands out in terms of rainfall data.
The levels of February and March towering over
the means and medians of the past 13 years.
Cyclone Yasi greatly affected Innisfail's rainfall.
600
500
400
300
200
100
0
Jan Feb Mar Apr May Jun
Monthly Total 2011
Jul
Aug Sep Oct Nov Dec
Mean 2000-2013
Median 2000-2013
Conclusion
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From the statistics gathered, we can come to a decision that Cyclone Yasi had
created a significant alter in the rainfall standards of Innisfail Queensland,
February 2011
In contrast to the days (slide 4), months (slide 5), and years (slide 6), Cyclone Yasi
has greatly impacted the results, which is evident in the surges it has caused
From mid January - mid February 2011, the rainfall levels ranged from 0 – 193ml of
rain. The 3rd of February 2011 being the highest peak, also a day within the time of
Cyclone Yasi
Out of all the February’s of 2000 – 2013, the results ranging from 107 - 1134,
February 2011, with 909ml of rain, having the third most level of rainfall.
And of the months of 2000 – 2013, the results range from 31 – 980ml. The second
highest point of 909ml being February 2011, the month of Cyclone Yasi and the
month of the second most highest level of rainfall out of the 156 months from
2000 – 2013
Cyclone Yasi: highest rainfall of mid Januray – mid February 2011 (1st out of 30
days), third highest of all February’s of 2000 – 2013 (3rd out of 12) and the second
highest rainfall of all months from 2000 – 2013 (2nd out of 156)
Reference: Climate Data Online. 2013. Climate Data Online.
[ONLINE] Available at: http://www.bom.gov.au/climate/data/.
[Accessed 05 September 2013]