Brian Gunter, a retired engineering hydrologist living in Narooma has just done an analysis of drought rainfalls in Narooma and thought that it may be of interest to Beagle readers. His analysis compares the present drought with historical droughts with the analysis is based on recorded rainfall data in Narooma over the past 109 years, since 1910. Narooma Drought Rainfalls: Narooma is a small town on the coast of New South Wales, Australia about 300 km south of Sydney. Continuous rainfall data are available for Narooma since 1910. New South Wales (NSW) has been experiencing a widespread and severe drought this year (2018). The extent is shown on the drought map produced by the Australian Bureau of Meteorology (BOM) – this map is for the six-month period March-August 2018. Narooma is in the “Severe Deficiency” zone,
In order to assess the severity of the present drought in comparison with historic droughts I have compared cumulative rainfall totals for various periods (3, 6, 9 and 12 months) up to the end of August in each year since 1910.
The results are shown in the following four plots:
3 MONTHS:
6 MONTHS:
9 MONTHS:
12 MONTHS:
The plots identify seven significant droughts that have affected Narooma since 1910. These were in 1915, 1923, 1954, 1968, 1980, 2009 and 2018. The rainfall totals for each of these droughts are shown in the following table:
It is seen that the present (2018) drought is not particularly severe. The most severe duration is for the 6-month period (March-August) which was the 5th lowest year (out of 109 years) since 1910. The 3-month rainfall for 2018 was the the 34th lowest, while the 9-month and 12-month rainfalls were respectively the 21st and 28th lowest since 1910. The 9-month and 12-month rainfalls for 2018 were barely less than the long-term mean rainfalls for these periods.
Apart from comparing the 2018 drought with other droughts over the past 109 years, the analysis indicates that there is no trend for droughts to be more or less frequent in recent decades. The seven identified droughts have been fairly evenly spaced in time over the past 109 years. Sorry folks but there is no evidence of climate change here!
All droughts, even those such as in 2018, have significant effects on local residents and communities and this is not disputed. Furthermore the present drought is still continuing now (20 September) so the duration and magnitude of the complete drought is yet to be determined. However, a positive certainty is that each day ahead is one day closer to the next significant rain! The Author: This article was written by Brian Gunter of Narooma, NSW, Australia. In his previous life Brian was an engineering hydrologist involved over many years in the analysis of rainfall and river flow data for the planning of water resources projects in Australia, Asia and Africa. In recent years he has been one of the Marine Rescue NSW (previously Royal Volunteer Coastal Patrol) volunteer weather observers who operate the Narooma station for the Bureau of Meteorology. (Visit Brian's website of all things Climate HERE)
