Evaporation Atlas for the Contiguous U.S. (1956-1970)

Maps are presented showing the areal distribution of evaporation in
the contiguous 48 states (1) observed from Class A pans from May
through October, (2) estimated for a free water surface (FWS) with
negligible heat storage from May through October, and (3) estimated
for an FWS for the entire year. A map is presented of coefficients to
convert from pan evaporation to FWS evaporation. Sources of data,
analyses of the maps, and limitations on their use are described. The
maps are printed on a scale of 1/4,800,000. The data set used
included, at most, 15 years. The data sets were adjusted to fit a
common base period 1956-1970. These values are considered a good
index to potential evapotranspiration or potential consumptive use.

Processing: Estimation equations were used when weather conditions
prevented reliable measurements.

These data are available in paper copy or microfiche at cost of
reproduction.