Saturday, 15 December 2007

'G'day' and 'Goodbye' Oz

I have stumbled across some treasure! It's a bit late perhaps but in the spirit of 'better late than never'.....

With only one day of the journey across Australia left, I followed some links and ended up in the webpages of the Australian Bureau of Meteorology . It is an absolute treasure trove of information about the weather and climate in Australia, as well as issues relating to global climate. I will certainly be bookmarking it for the future. However, the reason I found it was related to the route Mark followed into Brisbane today. Although the tracker is temporarily suspended, it was easy to follow the Gore Highway to Toowoomba which sits on the crest of the Dividing Range and on down to Brisbane.

Along the route it was field patterns which caught my eye and set me off on my investigations...... which finally led to the Australian Bureau of Meteorology (BOM).
Shortly after leaving Millmerran this morning, Mark cycled past features which looked as if map contours had been superimposed on the landscape. Closer inspection revealed this image...

The agricultural landscape suggests that the area is marginal for cultivation. However, where there are fields, they have been ploughed to follow the contours of the land. This is a classic technique in semi arid areas and is practised to retain water on the land and to prevent soil erosion. There is a good explanation of the practice here .

This part of Queenland receives about 800mm of rain in an average year. The problem however, is that the rain is not reliable. Lying in the rainshadow of the Dividing Range, it is often 'cut off' from the moist south easterlies which bring much more rain to the coastal parts of the state. In addition, high temperatures mean that there are high rates of evaporation and so the average rainfall (which is not dissimilar to what is received in eastern Scotland) is much less effective.

It was while I was researching the rainfall in Queensland that I found these excellent maps on the Australian BOM site The first is the total rainfall received across Australia in the last calendar year and the second shows detail of Queensland. You can see that the rainfall falls away sharply as you go inland from the coast of Queensland. Indeed, along the route Mark has cycled today, rainfall totals vary from about 400mm at Millmerran to 1200 mm at Brisbane. That is a very pronounced rainshadow effect!
Contour ploughing is just one way of responding to the rainfall shortage. Another common practice is strip farming and again, there is much evidence of this along the route Mark has followed today. If you follow the link, Wikipedia again gives a good explanation of the technique seen below at closer quarters near to Toowoomba. You will have to excuse me if field patterns seem rather dull to you but, believe me, this is real 'textbook stuff' and will provide me with a good case study the next time I'm studying dry farming techniques in school! Mark, understandably, will have given no thought at all to the patterns in fields today as his sights will have been set on Brisbane. I know how I am feeling having 'got across' this continent, and I can only imagine the sense of elation and achievement Mark must be feeling having pedalled the distance.

Like all the big cities of Australia which Mark has just passed through en route to somewhere else, I will also pass through Brisbane fairly swiftly as it is impossible to do justice to the geography of a city of that scale in a few lines. However, here are some photos gleaned from Flickr. They give an impression of a highly photogenic city... any time of the day

This short video also gives a flavour (and has a sound track which is a good 'valediction' to

And finally, after a 38 day crossing of Australia, Brisbane airport is where we leave this huge country. I used to think I knew quite a lot about Australia but all things are relative - I certainly know a lot more about it now!!

No comments: