Some handy physical constants and conversions

latent heat of fusion of water = 79.7 cal/g

latent heat of vaporization of water at 0C = 597 cal/g

latent heat of vaporization of water at 100C = 540 cal/g

specific heat of ice = 0.50 cal/g-C

saturation vapor pressure at 0C = 6.11 mb

1 inch per sq mi = 26.9 cfs-days

1 inch per sq mi = 53.3 acre-ft

1 acre-inch/hr = 0.9917 cfs (usually use 1 cfs)

1 ft = 0.3048 m

1 mile = 1.609 km

1 acre = 0.4047 ha = 43,560 ft²

1 cfs = 0.02832 cms

1 mgd = 1.55 cfs

1 mi² = 640 acres

1 ha = 10,000 m²

1 atmosphere = 1013.2 mb = 760 mm Hg = 29.92 inches Hg