"HW08 PARAMETER ESTIMATION TECHNIQUES MOPEX-3 WORKSHOP IUGG2003 Sapporo"
HW08 PARAMETER ESTIMATION TECHNIQUES MOPEX-3 WORKSHOP IUGG2003 Sapporo, Japan This was the third Workshop held as part of the World Climate Research Global Energy and Water Cycle Experiment (GEWEX) Model Parameter Estimation Experiment MOPEX) to enable the wider scientific community to address the issue of hydrological model parameter estimation. Over three days 28 presentations were made to this Workshop supported by some six posters. Presentations were under the following sub- themes of (i) Development and application of model calibration techniques, (ii) Review of model parameter estimation experiment workshop results, (iii) Parameter estimation and model diagnostic techniques, (iv) Uncertainties in modelling and information in data and (v) MOPEX's contribution to PUB and MOPEX future plan and direction. In addition to the discussion of each presentation a discussion period was held at the end of each sub-theme to draw out the key issues. The Workshop received strong support with at times over 100 participants to hear the invited speakers and good discussion of the issues. Considerable interest was shown in publishing a special issue of a Journal on Model Parameter Estimation and an accompanying IAHS Red Book. The final discussion session concerned future activities and support of PUB. It was agreed that a MOPEX-4 Workshop would be held in late 2004, accepting the offer of Cemagref located outside Paris. Data from more basins (100) from different climatic areas would be provided with a subset of these involving soft data for a detailed examination of its use. It was agreed that the Sapporo Workshop did not allow sufficient time to pursue the discussions in depth and that this would be a key feature of this Workshop. To partition the discussion to make it more structured PUB could be considered as the rational for MOPEX. Starting with Information (Soft/Medium/Hard Data) feeding by various methods into the Models (how should we build models, etc?), we need Theory/Empiricism and Philosophy to achieve this and can then consider Applications. From this we have four primary activities. The issues are: (i) How do we bring the information to bear on the models (identification, parameter estimation, data assimilation, evaluation is part of a whole host of issues)?; (ii) What are the right models? (Are they doing the right job for us?); (iii) Generalisation (the application of models to PUB, etc.) and (iv) Assessment of the methods, models and applications. To try and understand the results obtained it is planned to use of Diagnostic Methods akin to the approaches used by the atmospheric and climate modelling community. The MOPEX-5 Workshop is proposed for the VIIth IAHS Scientific Assembly to be held at Foz de Igassu, Brazil in mid 2005. This Workshop will present the results and findings of MOPEX-4 and will involve new, innovative analyses of the science questions and the application of a priori parameter estimation to a common set of basins over a wide range of different climatic regimes. The Workshop will also include additional contributions on a priori parameter estimation techniques applied to large-scale basin applications and specific regional/country applications where both model developers (modellers) and users (water managers) are involved. Based on these experiences, the discussions will be focused and structured to provide guidance to PUB and MOPEX on a refined set of science issues and provide a way forward to addressing and resolving these. John Schaake, Yun Duan, Alan Hall