This measure is included mostly for completeness. One practical use of the decameter is for altitude of geopotential heights in meteorology. Meteorologists also use another seldom encountered SI prefix: hecto- in hectopascal (hPa). The volumetric form (see below) cubic decametre is convenient for describing large volumes of water such as in rivers and lakes.
For surface the square decametre (dam2) is a common unit, albeit by the name are (a). The are is a measurement of area the size of 1 decametre by 1 decametre — the square decametre — 10 metres by 10 metres, equalling 100 square metres (100 m2).
For volumes the cubic decametre (dam3) is also used, 10 m by 10 m by 10 m, equalling 1,000 cubic metres (1,000 m3).