Aug 17, 2011

Tropical pines?

The Big Cypress water line has risen into the pinelands!

That’s the first time we’ve seen that since September of 2010.

A week of steady rains pushed the water line up into the pines

Wet seasons are defined by not just the height that swamp water peaks in early fall, but also by how long water stays at that elevated state.

The more technical term for the duration of flooding is hydroperiod.

Hydroperiod is the period of time, as measured in months, that the floor of the various habitat types – pinelands, marl prairie, cypress domes, and pond apple forests – hold water for any given year. Pinelands, and in particular the palmetto-bottomed mesic pines, form the uppermost rung of the swamp habitat ladder. When they become shallowly saturated, that means that sheetflow has spread to its full extent across the swamp and is flowing at full force.

Last year the mesic pines (red) stayed high and dry

The graph above shows annual hydroperiod in the pines over the years.

Like clockwork we can count on the water line rising into the hydric pines at some point of each summer and fall, but it isn’t until waters rise into the higher mesic pine – and stays there for multiple months – that we get our truly high-order fall floods. Examples of recent high flood years include the flood of record 1994-1995, 1999, 2005 and 2008.

How much data can you look at all at once?
Here's the full 20-year record all in one chart!

Last year was a low-order flood year in comparison.

The mesic pines stayed high and dry thanks in part to a lack of tropical rains. As you can see from the historic chart above, some of our deepest and longest stretches of pine-level flooding started or were prolonged by a visit from the tropics.


BStith said...


Your graphs are amazing, so clearly summarizing huge amounts of information, yet taking on the appearance of a work of art! Keep up the good work!


Robert V. Sobczak said...

Thanks Brad. This was sort of a post that only a swampologist could love. I was happy with how well the hydroperiod calendar came out. I'm continually amazed how great a way it is to dump and organize a bunch of data on one page. FYI, I plan to add it to the Go Hydrology's Swamp Tab in case you need it.

Dr. Tom said...


I second, third, and fourth Brad Stith's kudos about this post :-).
The annotations of different hurricanes, El Ninas and El Ninos, and floods the on the long term record are especially nice.

And it is amazing how much drier (so far) things are in Corkscrew not so far away from your slogging

Cheers, Tom

Robert V. Sobczak said...

Thanks Dr. Tom! I almost backed off on all the graphs in a single post but, as they are color coordinated, they ended up complementing each other quite well.