Using Probable Maximum Precipitation to Bound the Disaggregation of Rainfall

The Multiplicative Discrete Random Cascade (MDRC) class of model is used to temporally disaggregate rainfall volumes through multiplying the volumes by random weights, which is repeated through multiple disaggregation levels. The model development involves the identification of probability density f...

Full description

Bibliographic Details
Main Authors: Neil McIntyre, András Bárdossy
Format: Article
Language:English
Published: MDPI AG 2017-07-01
Series:Water
Subjects:
Online Access:https://www.mdpi.com/2073-4441/9/7/496
_version_ 1811295709081632768
author Neil McIntyre
András Bárdossy
author_facet Neil McIntyre
András Bárdossy
author_sort Neil McIntyre
collection DOAJ
description The Multiplicative Discrete Random Cascade (MDRC) class of model is used to temporally disaggregate rainfall volumes through multiplying the volumes by random weights, which is repeated through multiple disaggregation levels. The model development involves the identification of probability density functions from which to sample the weights. The parameters of the probability density functions are known to be dependent on the rainfall volume. This paper characterises the volume dependency over the scarcely observed extreme ranges of rainfall, introducing the concept of volume-bounded MDRC models. Probable maximum precipitation (PMP) estimates are used to define theoretically-based points and asymptotes to which the observation-based estimates of the MDRC model parameters are extrapolated. Alternative models are tested using a case study of rainfall data from Brisbane, Australia covering the period 1908 to 2015. The results show that moving from a baseline model with constant parameters to incorporating the volume dependency of the parameters is essential for acceptable performance in terms of the frequency and magnitude of modelled extremes. As well as providing better estimates of parameters at each disaggregation level, the volume dependency provides an in-built bias correction when moving from one level to the next. A further, relatively small performance gain is obtained by extrapolating the observed dependency to the theoretically-based bounds. The volume dependency of the parameters is found to be reasonably time-scaleable, providing opportunity for advances in the generalisation of MDRC models. Sensitivity analysis shows that the subjectivities and uncertainties in the modelling procedure have mixed effects on the performance. A principal uncertainty, to which the results are sensitive, is the PMP estimate. Therefore, in applications of the bounded approach, the PMP should ideally be described by a probability distribution function.
first_indexed 2024-04-13T05:37:30Z
format Article
id doaj.art-7aeb287309b4458e9b23ddf3b051a644
institution Directory Open Access Journal
issn 2073-4441
language English
last_indexed 2024-04-13T05:37:30Z
publishDate 2017-07-01
publisher MDPI AG
record_format Article
series Water
spelling doaj.art-7aeb287309b4458e9b23ddf3b051a6442022-12-22T03:00:14ZengMDPI AGWater2073-44412017-07-019749610.3390/w9070496w9070496Using Probable Maximum Precipitation to Bound the Disaggregation of RainfallNeil McIntyre0András Bárdossy1Sustainable Minerals Institute, The University of Queensland, St Lucia, Brisbane, Queensland 4072, AustraliaInstitute for Modelling Hydraulic and Environmental Systems, University of Stuttgart, Pfaffenwaldring 61, 70550 Stuttgart, GermanyThe Multiplicative Discrete Random Cascade (MDRC) class of model is used to temporally disaggregate rainfall volumes through multiplying the volumes by random weights, which is repeated through multiple disaggregation levels. The model development involves the identification of probability density functions from which to sample the weights. The parameters of the probability density functions are known to be dependent on the rainfall volume. This paper characterises the volume dependency over the scarcely observed extreme ranges of rainfall, introducing the concept of volume-bounded MDRC models. Probable maximum precipitation (PMP) estimates are used to define theoretically-based points and asymptotes to which the observation-based estimates of the MDRC model parameters are extrapolated. Alternative models are tested using a case study of rainfall data from Brisbane, Australia covering the period 1908 to 2015. The results show that moving from a baseline model with constant parameters to incorporating the volume dependency of the parameters is essential for acceptable performance in terms of the frequency and magnitude of modelled extremes. As well as providing better estimates of parameters at each disaggregation level, the volume dependency provides an in-built bias correction when moving from one level to the next. A further, relatively small performance gain is obtained by extrapolating the observed dependency to the theoretically-based bounds. The volume dependency of the parameters is found to be reasonably time-scaleable, providing opportunity for advances in the generalisation of MDRC models. Sensitivity analysis shows that the subjectivities and uncertainties in the modelling procedure have mixed effects on the performance. A principal uncertainty, to which the results are sensitive, is the PMP estimate. Therefore, in applications of the bounded approach, the PMP should ideally be described by a probability distribution function.https://www.mdpi.com/2073-4441/9/7/496rainfallPMPstochasticcascadefloodsdisaggregation
spellingShingle Neil McIntyre
András Bárdossy
Using Probable Maximum Precipitation to Bound the Disaggregation of Rainfall
Water
rainfall
PMP
stochastic
cascade
floods
disaggregation
title Using Probable Maximum Precipitation to Bound the Disaggregation of Rainfall
title_full Using Probable Maximum Precipitation to Bound the Disaggregation of Rainfall
title_fullStr Using Probable Maximum Precipitation to Bound the Disaggregation of Rainfall
title_full_unstemmed Using Probable Maximum Precipitation to Bound the Disaggregation of Rainfall
title_short Using Probable Maximum Precipitation to Bound the Disaggregation of Rainfall
title_sort using probable maximum precipitation to bound the disaggregation of rainfall
topic rainfall
PMP
stochastic
cascade
floods
disaggregation
url https://www.mdpi.com/2073-4441/9/7/496
work_keys_str_mv AT neilmcintyre usingprobablemaximumprecipitationtoboundthedisaggregationofrainfall
AT andrasbardossy usingprobablemaximumprecipitationtoboundthedisaggregationofrainfall