Isobath
Water
An imaginary line on the earth's surface or a line on a map connecting all points which are the same vertical distance above the upper or lower surface of a water-bearing formation or aquifer.
- — Service Hydrologist Reference Manual Glossary of Hydrologic Terms retrieved 2014-06-01
Weather
In hydrologic terms, an imaginary line on the earth's surface or a line on a map connecting all points which are the same vertical distance above the upper or lower surface of a water-bearing formation or aquifer