Intensity-duration-frequency (IDF) curves usefully quantify extreme precipitation over various
durations and return periods for engineering design. Unfortunately, sparse, infrequent, or short
observations hinder the creation of robust IDF curves in many locations. This paper presents the first
global, multi-temporal (1–360 h) dataset of generalized extreme value (GEV) parameters at 31 km
resolution dubbed PXR-2 (Parametrized eXtreme Rain). Using these data we generalize site-specific
studies to show that that GEV parameters typically scale robustly with event duration (r
2 > 0.88).
Thus, we propose a universal IDF formula that allows estimates of rainfall intensity for a continuous
range of durations(PXR-4). This parameter scaling property opens the door to estimating sub-daily
IDF from daily records. We evaluate this characteristic for selected global cities and a high-density rain
gauge network in the United Kingdom. We find that intensities estimated with PXR-4 are within
±20% of PXR-2 for durations ranging between 2 and 360 h. PXR is immediately usable by earth
scientists studying global precipitation extremes and a promising proof-of-concept for engineers
designing infrastructure in data-scarce regions
Funding
Natural Environment Research Council (NERC) via grant NE/R014361/1
This is an Open Access Article. It is published by IoP under the Creative Commons Attribution 3.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/