ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables. Depth, unsaturated zone Depth of the Unsaturated zone. The vadose zone, also termed the unsaturated zone, is the part of Earth between the land surface and the top of the phreatic zone, the position at which the groundwater (the water in the soil's pores) is at atmospheric pressure ("vadose" is from the Latin for "shallow"). Hence, the vadose zone extends from the top of the ground surface to the water table. Wikipedia https://en.wikipedia.org/wiki/Vadose_zone Added to support Critical Zone Observatory (CZO) data use cases.