IDF Trends Study With MSC Weather Data Using Regression Analysis in Ontario

Abstract

The Ministry of Transportation (MTO) uses Intensity Duration Frequency (IDF) information that was developed with Environment Canada weather information up to 1989 for various infrastructure designs. The IDF curves needed an update to ensure the drainage design for infrastructures are up to current standards given the current extreme precipitation. The goals of this research were 1) to update the old IDF information to current standards and to develop a web interface as a more accessible method to find IDF curves in Ontario, (MTO currently uses hardcopy of design manuals for IDF information) and 2) to study past weather trends to develop IDF curves for 2090. Regression analysis was used to update the IDF curves and the analysis was performed with independent variables: calendar year of the weather station (set to 2012), station longitude and latitude, station elevation, barrier height, slope Y, slope X and distance of the each weather station from the closest body of water. The result of the regression analysis was validated with Environment Canada and National Oceanic and Atmospheric Administration data, which showed little statistical differences. The “IDF Lookup Website” was developed as a more assessable method to obtain IDF information. The IDF Lookup Website interpolates weather information between weather stations, allowing the users to easily acquire IDF curves for Ontario by selecting the location of interest on a map. Finally, IDF information for 2090 was obtained using the regression analysis and the corresponding IDF curves for 1-hour storm duration in Ontario were produced. The results were then validated with McMaster’s downscaling study. The regression analysis and the downscaling study predicted similar weather trends and showed little statistical difference.