Design Rainfalls In A Climate Changing World

• Published in: WIT Transactions on the Built Environment 2014-01, Vol.139
• Main Authors: Becciu, G, Lewis, C, Mambretti, S, Sanfilippo, U
• Format: Article
• Language: English
• Subjects: Climate; Climate change; Design; Estimates; Hydraulic structures; Rainfall; Stations; Storms; Trends
• ISSN: 1746-4498; 1743-3509
• DOI: 10.2495/UW140151

Climate changes appear to be altering rainfall patterns. Rainfall intensities which were once accepted for the design of hydraulic structures may no longer be appropriate. With our knowledge about climate change we can no longer use rainfall records as a simple statistical data base. Data trends should be considered. In some areas rainfall depths may be decreasing while in other areas they may be increasing. In this paper, changes in rainfall depth and duration, which may be due to climate change, have been analysed. This paper focuses on rainfall from Milano, Italy. Some stations in the USA were also analysed to bring a global perspective on changes in rainfall. For each storm duration, simple linear trend lines were drawn through maximum intensities, producing IDF curves. Trendlines were drawn for the entire years of data and for datasets divided into decades. Kendall Tau tests were used to identify trends. The Pearson test was used to verify the applicability of the Gumbel distribution. As other authors showed, no trends can be claimed and, therefore, it is still possible to use the commonly adopted methods to estimate the design rainfalls.