Seepage and Evaporation Determination Using a Liquid Level Interferometer (Laser)

摘要

The report describes an interferometer designed to precisely measure the location of a fluctuating water level from a fixed point. This fluctuation is the combined influence of seepage, evaporation, dewfall, and precipitation. The interferometer will be used to measure fluctuation over time. During periods when the vapor pressure of the water is the same as the vapor pressure of the air, evaporation is negligible so that any water drop during this relatively short period of time would be seepage loss. Thus the instrumentation can be used to separate seepage from evaporation. Once the seepage is determined the instrumentation can be used to study the process of evaporation on a minute-by-minute basis.