Evaporation study at Silver Lake in the Mojave Desert, California

Silver Lake is located in the Mojave Desert north of Baker, California. It was formed within a period of three days as a result of a flood in the Mojave River in March 1938. Previously the lake had been dry for several years. Its maximum size was seven miles long and three miles wide. After this flood, daily observations were made of temperature, humidity, wind movement, precipitation, and pan evaporation at a Class A Weather Bureau evaporation station established adjacent to the lake, and of changes in water level and temperatures of the lake from May 1938 to April 1939. This paper presents a summary of these measurements. No inflow or outflow occurred during the study and the lake was entirely dry at the end of the following year. Borings in the tight clay lake bottom indicated there were no losses by seepage. The purpose of the study was to determine coefficients for converting pan evaporation to lake evaporation and to develop an empirical relation between evaporation and meteorological factors, under desert conditions. The results show that annual evaporation from Silver Lake was about 79 inches for the period of observation, and that a coefficient of 0.60 could be used in reducing Weather Bureau pan evaporation to lake evaporation in desert areas with similar climate.