Defying Classification

by Malcolm Tredinnick

Topic: science/weather

Fri 7 Dec 2007

...And Then The Rains Came

Posted at 18:55 +1100

I returned on Wednesday from a trip to the US (more about that in some future posts) and, since I've been back, the weather has been nothing but rain. Interspersed with the occasional thunderstorm. This, combined with a short report on last night's news saying that water catchment levels are at a recent high prompted me to go and look at the recent data. Thus, a quick update for my overseas climate enthusiast readers.

I've noted previously that the effects of long-term diminished rainfall and water restrictions are noticeable around even my relatively urban area, once I opened my eyes and started looking. Drought in "the country" is one thing, but what brings it home is when us city dwellers have to conserve water because we are literally running out of it. Earlier this year, the Sydney Catchment Authority (a.k.a people in charge of the big dams) were saying we had about 4.5 years of water left if rainfall stayed as it was. That was a little scary at the time.

Fortunately, things have definitely improved. The latest weekly report from the Catchmtent Authority shows that we have remained above 55% capacity for a couple months now and it is even ticking up slightly of late. The next mark of interest is 70%, which is considered fairly comfortable levels (100% being both obviously better and achievable — we were at 100% capacity back in 1998) for the future of the city's supply.

For the curious, I also stumbled across this page which gives a highly schematic map of where Sydney draws its water from. You would need to spend some time with an atlas or online equivalent to put those catchment areas into geographical perspective, something I don't have enthusiasm to do at the moment.

Topics: science/weather/drought

Mon 5 Nov 2007

Drought By Small Increments

Posted at 12:37 +1100

Over at the Inkstain presses, John's been publishing a lot of interesting little pieces lately about the immediate and very local effects of drought in places the US. His note about the drought web portal reminded me of something I'd been meaning to check out.

Following my return from a trip to New Jersey at the start of October, I wrote the following paragraphs about my impressions of the natural environment there. Looking at the drought service confirms that that area of the country isn't particularly severely affected. In that respect, it provides a contrast between my local area and the north-eastern USA:

South Plainfield, New Jersey, is a semi-urban area, lots of industrial parks — offices, a few storage places, about a dozen strip malls in a two mile radius and some medium-density housing. Walking between my hotel and the offices I was working in each day (maybe 1000 yards each way), it was really noticeable how different that part of the US is from where I live at the moment.

I could almost smell the water (more likely, the freshness of the plants, even after a long summer) in the ground and flora. Until being exposed to this difference and realised what I was seeing and smelling, it hadn't struck me just how dry things are, even around Sydney (which, let's be honest, is hardly suffering as much as rural areas of this country). Things like the smell of cut grass and dew on the ground in the morning. The really lush green of places with actual lawn, and even the nature strips along the roadsides. Trees that were full of leaves and growing fantastically.

It really hit me just how much things have changed locally in the past years. All the New Jersey surroundings were instantly familiar and brought back memories of growing up and even where I lived when I first moved to Sydney back in 1993. When you live in an area that changes by degrees month to month and year to year, you don't automatically realise how large the accumulated change is. Particularly when it's "home" and one's reference point for "normal". Looking around in the few days since I've been back, the signs of low rainfall are everywhere. Things don't look any different than they did before, but having been exposed to the alternative for a while, it's interesting to look with fresh eyes and notice the accumulated effect. The Australian bushland plants are the ones that are thriving. Imported species and those designed to live near water are looking much more straggly and definitely less dense than in past years.

Observing change as it happens is hard. We can all say the price of fruit and vegetables has increased over the past two or three years, but when did it really go up more at a particular moment than the normal variation and stay there? Was it observable at the time and not just in hindsight? The scientists who measure climate effects in real time and try to make predictions from underneath all the natural variations do not have an easy time of it. The critics who feel that dismissing such predications is easy because of their volatility are not considering the necessity of such actions, the difference between researching and critiquing, or the relative historical accuracy, and hence, relative success, of such predictions.

Topics: science/weather/drought, life