Wish for warm, but not that warm: why we need snow in Calgary
Tuesday, January 18, 2011
Home: Calgary, Alberta, Canada
Weather: Sunny, warmer, snowed a bit and it was actually quite bright and sunny and nice when I went out to shovel it. The snow was light and fluffy, not sticky and wet.
We live in a desert. We need all the water that comes from the sky, whether it’s falling as rain or snow.
When it gets too warm in mid-winter, the snow melts. If the snow would melt slowly enough to sink into the soil, it could replenish the invisible water supply in the ground. However, it often melts so fast that instead of sinking into the ground, much of the melted snow (water, in other words) runs off.
This is made worse by the fact that much of our city’s actual surface area is paved and impermeable. Water can’t sink in through sidewalks, roads, and rooftops.
So, the water flows off the street and down the culvert and eventually into the Bow River.
Then in the spring and summer, when we (the large-scale “we”, that is, including all the farmers) need it, there isn’t as much water stored in the soil as we would like.
Another way we lose water is by the dry Chinook wind picking it up and blowing it east.
We can do something about the city being covered in pavement (at least, theoretically we can), but we can’t change the Chinook.
Another bad thing about having the temperature go above freezing in winter is the wear and tear the freeze-thaw cycle puts on things like concrete bridges and roads. Freeze-thaw isn’t that good a thing to wish for. It is the mother of potholes.
Join me in hoping the temperature stays around minus 10 C with sun.
jill