Evaporation

The basin exhales

Most of the rain that falls on a basin never makes it to the river — it goes back to the sky. Evapotranspiration is the quiet thief in every water budget.

How we estimate it

ET         evapotranspiration, from energy balance
pan        still-weather evaporation, where we can
satellite  land-surface temperature, daily
crop       what the fields are pulling out

Why it matters

In dry basins, ET can be 90% of the budget. If you don't measure the exhalation, you can't balance the books.