Drought? – What Drought?
by M. J. Harvey –
December 2001
All Hallows Day – as I write, the rain comes down steadily, yet Victoria is still in a Level 3 water restriction. All summer the local press has had daily homilies about the level of the Sooke Lake Reservoir, the number of gallons used and the target consumption. The daily drip, drip of news
has reduced much of the population to a bunch of guilt-ridden reluctant toilet flushers. Lawns turned their natural brown colour (well, isn’t it?), flower beds were watered by hand using the correct spring-loaded hose attachment and casual conversation turned around how extremely dry it was and would it ever rain.
What a load of baloney! It is a truism that if you state something often enough people will believe it. That happened with the so-called drought of the summer of 2001.
I keep a daily record of maximum and minimum temperatures and the precipitation. 2001 had a damp summer. It was the winter rainfall previously that had failed to fill the reservoir. We were talking about a winter drought not a summer drought. Let me give you a few figures from my Sooke property. I should admit that Sooke is on the damper side of Victoria. I was assured by one Ten Mile Pointer that the rain I had did not penetrate to their neck of the woods. Well that is the penalty for living in the rain shadow of Mt. Tolmie.
The drought period for gardeners basically starts in May and runs through September. Here are a few of the previous years’ figures:
|
|
May |
June |
July |
August |
September |
Total |
|
2001 |
41 |
21 |
17 |
66 |
26.5 |
171.5 |
|
2000 |
44 |
39 |
18 |
8 |
32 |
141.0 |
|
1999 |
21 |
23 |
9 |
23 |
14 |
90.0 |
|
1998 |
28 |
18 |
34 |
0 |
09 |
89.0 |
|
1997 |
69 |
52 |
43 |
31 |
140 |
335.0 |
|
1996 |
44 |
10 |
11 |
9 |
46 |
120.0 |
You can see that purely on rainfall, 2001 was a pretty damp summer, exceeded only by the miserable 1997 chain of depressions.
Of course maximum temperatures and wind strongly affect how plants grow. The hotter it is and the more wind we have the more water plants lose through their leaves. Hot summers and/or lots of root weevils result in the edges of leaves turning brown. So meteorologists have a measure called ‘evapo-transpiration’ which takes the evaporation from the soil and vegetation into account. Unfortunately this is hard to measure since it integrates precipitation, wind speed and temperature. My impression for 2001 was that since we had a fair amount of cloud and not so high maximum temperatures, it wasn’t so stressful for the plants. But who am I to accuse the press of exaggeration? They wouldn’t do that – never!
Incidentally we have in Victoria an expert, Dr. Hans Roemer, on climate and plant zones. He gives a vivid if detailed talk on how the climate of Victoria stacks up with those of other regions.