Jun 5, 2015

Bellwether roots

Among the many hydrologic bellwethers in the swamp ...

Is gauging drought by when (and how long) pond apples roots go dry.

This bar chart reports the duration (in months) that the water table has dropped below the  roots  of the pond apples trees in Big Cypress National Preserve.  The years 2001 and 2011 were the droughts of record.  Pond apple roots were exposed close to or over 4 months during those years.  During the wet winters of 2003 and 2010 the pond apple roots stayed submerged all spring.  Can you see how recent years have been drier than the wetter period in the 1990s?

This year it's been 2.3 months, i.e. 11 weeks (and going.)

The long-term average is 1.4 months.

By long term I mean the past 25 years. Before canals and levees the pond apple probably never, or only rarely, ever went dry.

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