Snow surveys and runoff forecasting from photographs

TitleSnow surveys and runoff forecasting from photographs
Publication TypeConference Proceedings
Year of Conference1937
AuthorsPotts, H. L.
Conference Name5th Annual Western Interstate Snow Survey Conference
Series TitleProceedings of the 5th Annual Western Interstate Snow Survey Conference
Date PublishedJune 1937
PublisherAmerican Geophysical Union, Transactions, Part II:
Conference LocationDenver, Colorado
KeywordsPhotography measurement of snowline, Water supply forecasting
Abstract

A series of photographs was taken from the same point of a high range near Hoosier Pass, Colorado, at intervals throughout the year. The percentage of the area covered by snow in each photograph was calculated by superimposing a transparent template on the picture and counting the squares in which snow appeared. The total runoff was calculated on Nov. 1 from the date on which each photograph was taken. Curves for 3 consecutive years were plotted as functions of snow cover and runoff on the same chart. Considerable variation in precipitation was obtained. It is shown that the distance between the 3 curves is approximately directly proportional to the differences in recorded precipitation. The total amount of water which will be available for use is determined by calculating the ratio between total runoff and total diversions at the city intake for an average year.