Ticker for August 1, 2002

                
MESONET TICKER ... MESONET TICKER ... MESONET TICKER ... MESONET TICKER ...
August 1, 2002     August 1, 2002     August 1, 2002     August 1, 2002


How Much Water Does Your Lawn Use?

Did you know that a third-inch of water (or more!) can be lost from
a bermuda lawn in a day?  Evapotranspiration (ET) is the combination
of two processes: evaporation and transpiration, which is the release
of water vapor through plant life processes (don't laugh - you breathe
off water vapor, too!)

ET is a supply-and-demand process, meaning the surface isn't always
able to surrender water at the rate the atmosphere demands it.

This time of year, warm air, a high sun and breezy winds can really
add up to tax near-surface water at a rate of 10 inches per month!
Considering that our normal monthly rainfall during the summer is
two to four inches, it's pretty obvious that the atmosphere can't
always get what it wants.

The "E" part of ET is good-old-fashioned evaporation, and evaporative
demand increases dramatically during daylight hours.  That's why
residents are encouraged to water between dusk and dawn - so more of
that water makes it into the ground!

Finally, the Oklahoma Mesonet operates the Oklahoma Evapotranspiration
Model, which was adapted at Oklahoma State University.  The model
generates daily output for several grasses, based on local Mesonet
data.  There's even a lawn irrigation scheduling form to help folks
deliver the right amount of water to their lawn at the right time!

You can check out the Oklahoma Evapotranspiration Model at the Mesonet's
AgWeather pages: http://agweather.mesonet.org/  Click on "Models",
then "Oklahoma Evapotranspiration Model".