Convert Acre-feet per second to Cubic kilometres per year

Convert Acre-feet per second (ac-ft/s) to Cubic kilometres per year (km³/yr) instantly and accurately.

Acre-feet per second (ac-ft/s)
Cubic kilometres per year (km³/yr)

Conversion Formula

km³/yr = ac-ft/s × 38.92572644

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.

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 second (ac-ft/s)Cubic kilometres per year (km³/yr)
1 ac-ft/s38.9257 km³/yr
2 ac-ft/s77.8515 km³/yr
5 ac-ft/s194.629 km³/yr
10 ac-ft/s389.257 km³/yr
25 ac-ft/s973.143 km³/yr
50 ac-ft/s1946.29 km³/yr
100 ac-ft/s3892.57 km³/yr

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