Feb 28, 2012

Spring drought repeat?

The swamp had a huge wildfire last spring …

Could this spring be shaping up the same?

Major wildfires tend to coincide
with deep drops in the water table

To answer that we can look to water levels.

In general, we know that as water levels drop through the winter and spring more and more wetland becomes exposed as dry land until at some point there is hardly any water to be found.

That’s the time when wildfires can really spread.


Below is a hydrograph of water stage in Big Cypress Nat’l Preserve partitioned to show six horizontal categories of drought severity. From lowest to highest they are (1) peak water, (2) sheetflow season, (3) fire breaks are flooded, (4) fire breaks dwindle, (5) swamp is bond dry, and (6) extreme drought.

Wildfires are biggest and most dangerous when the water table drops deeply (and for prolonged periods) into the orange and red zones.

Can you see the water table's deep dip
into drought (red) last spring?
The calendar chart below applies the same color coding to the past twenty years.

Can you see how the 1990s were wetter than the 2000s? The Jarhead fire also jumps out as having occurred during our deepest and most prolonged dry period of the past twenty years.

Wildfires are the biggest threat
when natural water breaks go dry.

Thus, to answer original question:

We aren’t at that level of drought yet …
But then again it isn’t even spring!

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