The State of Drought

Drought Monitor for Virginia
Drought Monitor for Virginia

“Drought—what drought?” That was a typical response to my question before this week’s news of wildfires in Virginia and the Governor declared a state of emergency. I’m sure farmers, beekeepers, gardeners, foresters, and firefighters have worried for weeks, if not longer, about the lack of rain. The difference in perception depends on how close we live to the soil. I noticed a deficiency before my garden well ran dry and a blanket of fall leaves crisp as cornflakes and far more flammable.

I understand puzzled reactions while lawns remain green, and we haven’t had a hose-pipe ban yet. The drought is less severe here than in Shenandoah and north-west of the state. Besides, plants are getting some relief on dewy mornings and there’s less evaporation than in July and August.

A drought can be overlooked until it becomes severe from creeping forward slowly and having impacts that vary with soil type, plant species, and temperature. For the same reason, climate deniers take cover when a sizzling summer is followed by a wet autumn and/or a chilly winter.

Rising sea levels and melting glaciers are undeniable evidence of global climate change whereas the weather is debated more, sometimes hotly. What is normal? Are memories of idyllic summers spent on the beach and winters sledding in our youth our baseline? Most people prefer a plain plus or minus answer whereas it comes down to probabilities (plenty of scope for politically motivated interpretation).

The US Drought Monitor keeps an archive of dry and wet periods since records began in 1895 (and from 400 AD based on dendrochronology). The dark red spikes on the graph for Virginia represent intense drought, and the reciprocal navy blue spikes show extreme wetness. The range between extremes is huge, and much greater than the famously damp UK climate (though recent storms begin to undermine its reputation for moderate weather).

Anthropogenic impacts on climate are reckoned to be notable after 1950. The graph doesn’t reveal much difference to my eyes. An algorithm using the raw data is needed to check if the pattern is random or has a subtle periodicity.  

By Roger Gosden

A British and American scientist specializing in reproduction & embryology whose career spanned from Cambridge to Cornell's Weill Medical College in NYC. He married Lucinda Veeck, the embryologist for the first successful IVF team in America. They retired to Virginia, where he became a master naturalist and writer affiliated with William & Mary.

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