What is Evapotranspiration Part I:Detailed knowledge of evapotranspiration rates is essential for a successful green roof. In this audio article, we dive into the topic of evapotranspiration. If you would like to read the article, it is available here:https://www.purple-roof.com/post/what-is-evapotranspiration Evapotranspiration is merely a combination of the words: evaporation (evapo-) and transpiration (-transpiration). But what do these two terms mean? Let’s start with evaporation!