Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis
Showing posts with label Bega_Valley. Show all posts
Showing posts with label Bega_Valley. Show all posts

Tuesday, February 16, 2010

More about the South Coast rains and damage

Mick from "Sandy Straits and Beyond" asked me today if the rains I had talked about was what had been now declared a Natural Disaster.
In short, yes.

I did make a somewhat flippant comment that the local Member is also the Minister for Emergency Services. In fact. the Minister, Steve Whan MLA, is the Member for Monaro, not the Member for Bega. His father Bob Whan,was the former Federal Member for Eden-Monaro. But Steve Whan is not responsible for this area. That should be clarified.

The Canberra Times had a story today on a road collapse at Tilba, just south from Narooma, caused by this storm event.
Floodwaters washed out the Tilba-Punkalla road yesterday
Photo: BRUCE COULSON

I acknowledge that this is a dramatic road collapse, and I recall a similar event near Gosford that resulted in the death of five members of a family caught up in floodwaters. In no way do I wish to minimise the risk of such an event, but the danger lies in the sudden and unpredictable event of the road collapse, not the magnitude of the storm event. See Footnote below.

The main point I was trying to make in the comments earlier was that the ABC radio today reported that the Minister's declaration was made on the basis that there was some $4 million worth of road and other infrastructure damage.

Do you realise how $4 million worth of road repairs would buy? It would barely amount to the rebuilding of a single road bridge. No doubt the true costs of this storm will far exceed the original estimates. But I keep repeating, this is a small flood event, relative to large floods.

What the Bureau of Meteorology was at pains to explain today was that the large rivers in the region (Deua River - at Merimbula, Tuross River - at Tuross Lake and Bega River - at Bega) have been "swollen", but not in full flood. So it is actually the little creeks and rivers which have risen and blocked roads and done some minor damage. I include the road washaway above in this category, even though it is potentially fatal for motorists. It is just a little stream, grown large, briefly.

This storm event needs to be put in context. In 1971 the Bega River (which has a large*** catchment) flooded, and it took out a relatively new bridge near the River mouth. It took about 2 years to replace. People at Tathra had to drive an extra 40 Kms around the river for about two years. Today there is a very large, high clearance bridge across the Bega River, just near the mouth - and the locals are very proud of it. For good reason.

This flooding event is nothing like that.

Tyto Tony at Ingham lived through worse than this three times a year ago.

Footnotes:
"The highest flood on record occurred in February 1971. Up to 900 mm of rain fell in 15 days over the catchments of the Bega and Bemboka Rivers. ...
"An anecdotal record of flooding in the Bega Valley has been compiled by Smith (1978) who recorded a total of 39 floods in the valley during the period 1851 to 1978."
Source: Bega River Estuary - Data Review

*** The Bega Valley is a "large catchment" relative to most other NSW coastal catchments. Of course, the inland catchments are far, far greater in area. The coastal catchments however, trap large amounts of rain because of the presence of the Great Dividing Range, relatively close to the Pacific Ocean, especially when triggered by post-cyclonic storms, such as this one. That means they are prone to sudden and quite dramatic flood events. The Hunter River (at Maitland), the Clarence (at Grafton and below) and the Wilsons River (at Lismore) are probably the most flood prone of these coastal NSW rivers.

Monday, December 17, 2007

An unusual plant leads me to Louisa Atkinson.

Louisa Atkinson,(first name Caroline) was born in 1834, at Oldbury, a well-known historic property in Sutton Forest. She is acknowledged as a pioneer botanist, and author, (and trail-blazer). It would be anachronistic to proclaim her to be a feminist, but none-the-less, it seems the title would suit her.

She discovered a number of new plant species in the Blue Mountains and Southern Highlands regions of New South Wales. She collected the first specimens of many species of plants, and these were sent to Reverend William Woolls, (a famous early colonial botanist) or to Baron Ferdinand von Mueller, the first Director of the Royal Botanic Gardens in Melbourne, who named a number of species after her.

This plant Xanthosia atkinsoniana,
was named in Louisa's honour by Baron von Mueller.

I found this specimen growing in Medway, a small village on the sandstone plateau, about 5 Km south-west from Berrima. It is appropriate to note that Medway is located a mere 8 Km north-west from Oldbury, where Louisa Atkinson first learnt to explore the Australian bush, which she knew and loved so well.

Pink buds of Xanthosia atkinsoniana,
and white mature flowers.
When I eventually identified this unfamiliar plant (unfamiliar to me, at least) I was thrilled to realise that it was growing where Louisa might well have first stumbled upon it, some 150 years before me. For me it was like reaching out to touch a little piece of botanical history.

This is botanical illustration for Xanthosia atkinsoniana from PlantNet (from the website of the "Royal Botanic Gardens Trust" in Sydney).

Botanically, this plant is interesting, for its flower structure is characteristic of the Celery and Parsley group of plants (Apiaceae family). The umbel structure of the inflorescence are typical of this family. This plant has flattened bracts beneath the flowers, and leaves which are very similar to the most famous Australian member of this family, the Flannel Flower (Actinotus helianthi).

The flattened seed structure, which is divided laterally into two parts, is clearly illustrated. You can see in the single flower (below) the bulbous structure from which that dried seed will take its final shape. It was this diagnostic shape of the individual flower which led to my positive identification of this plant.Once I had a name for it, a quick Google Image search produced a definitive image, from the wonderful plant index and gallery for the Bega Valley (NSW). That image is so clear, that I was totally confident of my identification of my specimen. Thanks are due to Jackie Miles and Max Campbell for that wonderful plant photo gallery.

Gaye from the Hunter (and other readers) might well find this easy-to-use plant and fungi index to be useful for identifications, as I am sure I will, in future, now that I have found it. Some plants have localised distribution, but I am sure there will be many plants found in the Bega Valley which will also be found in the Southern Highlands, and the Hunter Valley. Such was the case with this Xanthosia species.

Epacris calvertiana var versicolor
, another local plant (from the Belmore Falls and Barren Grounds areas), is also named after Louisa (after her married name).