Convert Acre-feet per day to Cubic kilometres per year
Convert Acre-feet per day (ac-ft/d) to Cubic kilometres per year (km³/yr) instantly and accurately.
Conversion Formula
km³/yr = ac-ft/d × 0.0004505292412
About Acre-feet per day
The acre-foot per day (ac-ft/d) equals 1233.48183754752/86400 ≈ 0.014278 m³/s, the practical unit for daily water-delivery scheduling in western US irrigation districts and river-compact administration. Water rights in the Colorado River system are specified in acre-feet per year; daily delivery schedules convert to ac-ft/d. A moderate-size irrigation lateral delivers 5-50 ac-ft/d. 1 ac-ft/d ≈ 0.014278 m³/s ≈ 504.2 US gal/min.
About Cubic kilometres per year
The cubic kilometre per year (km³/yr) equals 10⁹/(365.25×86400) ≈ 31.688 m³/s, the unit used in global hydrology, glaciology, and climate science for river basin runoff, ice-sheet mass balance, and groundwater storage change. Total global freshwater river runoff is ≈37 000 km³/yr; the Amazon alone contributes ≈6 600 km³/yr; the Greenland ice sheet loses ≈280 km³/yr to melt and calving. 1 km³/yr ≈ 31.69 m³/s.
Quick Reference Table
| Acre-feet per day (ac-ft/d) | Cubic kilometres per year (km³/yr) |
|---|---|
| 1 ac-ft/d | 0.000450529 km³/yr |
| 2 ac-ft/d | 0.000901058 km³/yr |
| 5 ac-ft/d | 0.00225265 km³/yr |
| 10 ac-ft/d | 0.00450529 km³/yr |
| 25 ac-ft/d | 0.0112632 km³/yr |
| 50 ac-ft/d | 0.0225265 km³/yr |
| 100 ac-ft/d | 0.0450529 km³/yr |