Broderick_et_al-2016-Water_Resources_Research.pdf (6.97 MB)
Download fileTransferability of hydrological models and ensemble averaging methods between contrasting climatic periods
journal contribution
posted on 2016-11-25, 11:05 authored by Ciaran Broderick, Tom Matthews, Robert WilbyRobert Wilby, Satish Bastola, Conor MurphyUnderstanding hydrological model predictive capabilities under contrasting climate conditions enables more robust decision making. Using Differential Split Sample Testing (DSST), we analyze the performance of six hydrological models for 37 Irish catchments under climate conditions unlike those used for model training. Additionally, we consider four ensemble averaging techniques when examining interperiod transferability. DSST is conducted using 2/3 year noncontinuous blocks of (i) the wettest/driest years on record based on precipitation totals and (ii) years with a more/less pronounced seasonal precipitation regime. Model transferability between contrasting regimes was found to vary depending on the testing scenario, catchment, and evaluation criteria considered. As expected, the ensemble average
outperformed most individual ensemble members. However, averaging techniques differed considerably in the number of times they surpassed the best individual model member. Bayesian Model Averaging (BMA)
and the Granger-Ramanathan Averaging (GRA) method were found to outperform the simple arithmetic mean (SAM) and Akaike Information Criteria Averaging (AICA). Here GRA performed better than the best individual model in 51%–86% of cases (according to the Nash-Sutcliffe criterion). When assessing model predictive skill under climate change conditions we recommend (i) setting up DSST to select the best available analogues of expected annual mean and seasonal climate conditions; (ii) applying multiple performance criteria; (iii) testing transferability using a diverse set of catchments; and (iv) using a multimodel ensemble in conjunction with an appropriate averaging technique. Given the computational
efficiency and performance of GRA relative to BMA, the former is recommended as the preferred ensemble averaging technique for climate assessment.
Funding
C.M. and C.B. acknowledge funding provided by the Irish Environmental Protection Agency under project 2014-CCRP-MS.16.
History
School
- Social Sciences
Department
- Geography and Environment
Published in
Water Resources ResearchVolume
52Issue
10Pages
8343-8373Citation
BRODERICK, C. ... et al, 2016. Transferability of hydrological models and ensemble averaging methods between contrasting climatic periods. Water Resources Research, 52 (10), pp. 8343-8373.Publisher
© American Geophysical Union PublicationsVersion
- VoR (Version of Record)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Acceptance date
2016-10-05Publication date
2016-10-17Copyright date
2016Notes
An edited version of this paper was published by AGU. Copyright 2016 American Geophysical Union. To view the published open abstract, go to http://dx.doi.org/10.1002/2016WR018850ISSN
0043-1397eISSN
1944-7973Publisher version
Language
- en