m²/yr
square meter per year
Diffusivityexact by definition
The square metre per year is one square metre per Julian year of 31,557,600 seconds, that is about 3.169 × 10⁻⁸ m²/s. The relation is exact given the Julian year, though the decimal must be rounded. It is the customary unit for the coefficient of consolidation in geotechnical settlement analysis and for slow contaminant transport.
Watch out: Which year is meant matters at the fourth significant figure: this unit uses the Julian year of exactly 365.25 days. Some geotechnical software uses a 365-day year instead, a 0.07% difference that is well inside the uncertainty of the soil parameter itself.
| 1 m²/yr | 0.031688088 mm²/s |
Solvers that use diffusivity