Development of regional rainfall intensity-duration-frequency estimates for the state of Michigan

Document Type

Conference Proceeding

Publication Date



Due to the occurrence of high-intensity rainfall events more frequently than expected, the Michigan Department of Transportation has deemed it necessary to update the regional rainfall intensity-duration-frequency (IDF) estimates for the State. Rainfall intensity estimates are to be determined for each of seven durations (1, 2, 3, 6, 12, 18 and 24 hours) and six frequencies (0.5, 0.2, 0.1, 0.04, 0.02, and 0.01 per year). Traditionally, method of moments or maximum likelihood procedures have been used to fit a suitable probability distribution to annual maximum or partial duration series data for each gage, and isopluvial maps have been developed from these site-specific IDF estimates using interpolation procedures and judgment. This paper discusses the application of a regional frequency analysis approach based on probability-weighted moments that promises to provide more objective and robust IDF estimates. Definition of homogeneous regions, selection of a distribution, and estimation of parameters are discussed. Copyright ASCE 2004.

Publication Title

Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships