Incorporating uncertainty analysis into a regional IDF formula

✍ Scribed by Pao-Shan Yu; Chia-Jung Cheng

• Book ID: 101282478
• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 277 KB
• Volume: 12
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/(sici)1099-1085(19980430)12:5<713::aid-hyp610>3.0.co;2-j

✦ Synopsis

A rainfall intensity±duration±frequency (IDF) relationship was generated by pooling annual maximum rainfall series from 14 recording rain gauges in southern Taiwan. Dimensionless frequency curves, plotted by the growth curve method, can be well ®tted by regression equations for a duration ranging from 10 mins to 24 hours. As the parameters in regression equations have a good statistical relationship with average annual rainfall, a generalized regional IDF formula was then formulated. The formula, based on average annual rainfall as an index, can be easily applied to non-recording rain gauges. This paper further applies the mean value ®rstorder second moment (MFOSM) method to estimate the uncertainty of the proposed regional IDF formula. From a stochastic viewpoint, the generalized regional IDF formula can accurately simulate the IDF relationship developed using frequency analysis (EV1) at individual stations. The method can provide both rainfall intensity and variance isohyetal maps for various rainfall durations and return periods over the study area.