Convert Cubic kilometres per year to Acre-feet per second
Convert Cubic kilometres per year (km³/yr) to Acre-feet per second (ac-ft/s) instantly and accurately.
Conversion Formula
ac-ft/s = km³/yr × 0.02568995088
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.
About Acre-feet per second
The acre-foot per second (ac-ft/s) equals 1233.48183754752 m³/s, an enormous unit representing the flow that would fill a football-field-sized area to 1 ft depth every second. It appears in descriptions of exceptionally large dam-break flood waves and major river-system extreme events. The 1976 Teton Dam collapse peak outflow was estimated at ≈65 000 ft³/s ≈ 1.49 ac-ft/s. 1 ac-ft/s = 1 233.48 m³/s.
Quick Reference Table
| Cubic kilometres per year (km³/yr) | Acre-feet per second (ac-ft/s) |
|---|---|
| 1 km³/yr | 0.02569 ac-ft/s |
| 2 km³/yr | 0.0513799 ac-ft/s |
| 5 km³/yr | 0.12845 ac-ft/s |
| 10 km³/yr | 0.2569 ac-ft/s |
| 25 km³/yr | 0.642249 ac-ft/s |
| 50 km³/yr | 1.2845 ac-ft/s |
| 100 km³/yr | 2.569 ac-ft/s |