The timing of runoff response in design flood analysis

✍ Scribed by A Ashfaq; P Webster

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 945 KB
• Volume: 14
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/(sici)1099-1085(200005)14:7<1217::aid-hyp36>3.0.co;2-5

✦ Synopsis

This study presents an investigation of the time to peak of unit response functions for design ~ood studies[ It is based on an empirical analysis of observed rainfallÐruno} data for 38 basins in the UK and explores the relationship between unit response time to peak "t p # and ~ood peak magnitude "Q p #[ The results show that t p varies signi_cantly between events but suggest a systematic relationship between t p and Q p [ The relationships which have been developed suggest that t p decreases with ~ood magnitude and approaches to an asymptotic value for very large values of Q p [ These _ndings con_rm numerous physical and _eld investigations and also support the reduction in response time for probable maximum ~ood "PMF# recommended in the Soil Conservation Services method\ the Flood Studies Report method and the Flood Estimation Handbook[ The _ndings also suggest that t p should be modi_ed in unit hydrograph methods of design ~ood analysis for return periods that di}er from those used in deriving unit hydrographs[ A simple correction curve has been developed for adjusting t p according to the design ~ood return period[