About PDM
The Probability-Distributed Model, or PDM, is a general conceptual rainfall-runoff model which transforms time-series of rainfall and evaporation to river flow at the catchment outlet (Moore, 1985, 1999, 2007).
The model formulation is based on a probability-distributed moisture store and translation of runoff and drainage via routing stores.
Hydrological Applications
The PDM is used for operational flood forecasting across the UK and abroad. It has been applied to a wide range of hydrological studies including climate change impact (e.g. Kay & Jones (2012), Kay et al. (2020)), water resource management (e.g. eFLaG) and modelling ungauged locations (e.g. Kay et al. (2007)).
Methodological developments include enhanced groundwater representation (Moore & Bell, 2002), inter-catchment water exchange and multi-zone functionality for modelling mixed urban/rural catchment responses and higher/lower rainfall areas.
PDM Functionality
The PDM software is available under licence in two forms:
- PDM for PCs. A Windows-based application for interactive model calibration and assessment.
- UKCEH XML Module Adapter. An executable module for use in operational flood forecasting systems (e.g. Delft-FEWS) and for batch processing on Windows and Linux systems.
The PDM software has the following features:
- model toolkit to represent a variety of catchments
- choice of time-step, such as 15 minutes and daily
- choice of instantaneous or accumulated flows
- forecasts created using state-updating or error-prediction methods
- comprehensive manual
In addition, the PDM for PCs calibration application has the following functionality:
- automatic and interactive calibration facilities
- graphical user-interface
- output to Excel and other graphical tools
- automated event selection
- performance assessment of threshold-crossings and flood peaks
- wide range of statistical analyses
Contact for further information
For further information on PDM, please contact Bob Moore via the ForecastModelSupport@ceh.ac.uk email.
Bob Moore
UK Centre for Ecology & Hydrology
Wallingford
OX10 8BB
United Kingdom
Telephone: +44(0)1491 692262
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