Sunday, October 16, 2011

Drought the Destroyer

I've recently been reading here and there about the infrastructure-destroying effects of drought, and it's quite an interesting topic. As you may know, Texas has been undergoing a rather severe drought for some time, and, despite occasional slight alleviation, it's still continuing. When we think of droughts and the people they effect, we usually think of farmers; these are in many ways the most crucial victims of drought, but they are not the only ones. Drought can have major effects on infrastructure across the board. The most visible sign occurs on highways, which undergo longitudinal cracking -- that is, cracks in the direction of the traffic. This sort of crack can have a number of different causes, but few are so dramatic as those caused by drought. As the earth at the edge of the road (both beside it and immediately underneath it) becomes drier and drier, it contracts and compresses, bending the edge of the road away from the center. The action is very slow but nonetheless dramatic in effect; it can result in longitudinal cracks as broad as your palm going on for yards. Unfixed, a road can begin to look like it's been shredded. Roads running across culverts can experience the same thing, but across the breadth rather than the length of the road, as the road on both sides of the culvert begins to sag.

Perhaps even more immediate in its impact on people, however, is that exactly the same thing happens to house foundations: the slab begins to sag and crack, leading to serious foundation problems and sometimes broken plumbing.

We tend to think of catastrophes and disasters as swift-moving things; but all nature really needs to destroy human works is a little time under the right conditions: slowly the whole thing cracks, breaks, dissolves, and falls away. The one advantage of living through a slow-moving natural disaster over living through a fast-moving natural disaster is that you can partly keep up with the former, correcting some of the problems as they develop rather than having to deal with them all at once. But even there you are always playing catch-up.