Rainfall Variations as Influenced by Wind and Topography

Abstract Precipitation catch variation as influenced by wind direction and speed, topography and season are examined for the Deer-Sloan Creek watershed, located about 10 mi southeast of Michigan State University, East Lansing. Data for a 10-year period from dual traverse recording rain gages, calibrated twice a year, are ranked for each precipitation event by wind direction and speed. The annual frequency distribution of first-place rankings are arrayed by wind direction and speed to assess the possible influence of surrounding terrain on gage catch. A strong correlation was found to exist between the gage exposure and the surrounding topography as a function of the first-place rankings.