Quantification of rainfall DDF relationships at ungauged sites in Hong Kong

Information of rainfall depth-duration-frequency (DDF) is essential for hydrosystem engineering design and management. Although such information can be derived at raingauge sites, it is not available at ungauged locations. Loss of information at ungauged sites may affect the reliability of the engineering design. In this study, Ordinary Kriging is applied to estimate statistical features of annual maximum daily rainfalls at ungauged sites based on the information obtained at raingauge locations. The daily rainfall-based DDF generation framework is a scaling model. For illustration, the methodological framework is applied to derive rainfall DDF relationships at four selected ungauged sites in Hong Kong. © 2013 American Society of Civil Engineers