MTO Intensity-Frequency-Duration Renewal - Phase III: Validation of the Interpolation Tool

This paper will describe the work-in-progress, primarily to validate the Intensity-Density-Frequency Curve web interface previously developed for the Design and Contract Standards Office at the Ministry of Transportation Ontario (MTO). Results will be validated using data from nearby jurisdictions and by expanding the database to include data recorded at non-network weather stations within Ontario.

Overall validation of the system will use the recently available results for selected US Great Lakes states. We expect a good match with some differences due to analysis methods. For example, the US studies use a three-parameter IDF equation while the MTO model uses a two-parameter version.

Validation of the procedural alternatives selected for the MTO analysis will be performed using the Ontario Phase I and Phase II results. The base case will be methods recommended in the MTO Drainage Management Technical Guidelines (1989) for station analysis and the MTO square grid technique for regionalisation

A weighting technique developed in a previous phase of the project will be adapted to produce a quality control measure that can be used to manage entry of non-network data. Preliminary tests suggest that the technique may allow detection of time trends.

Finally, the project will produce an improved web interface that will allow the users to download their requested storm data, as well as specify specific storm parameters, and provide an onscreen graphic representing their hydrological footprint.