Available translations: English

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, , , ). 

The model formulation is based on a probability-distributed moisture store and translation of runoff and drainage via routing stores. 

A schematic of the Probability Distributed Model (PDM)鈥�
The Probability Distributed Model (PDM)

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. , ), water resource management (e.g. eFLaG) and modelling ungauged locations (e.g. ).

Methodological developments include enhanced groundwater representation (), 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.
PDM for PCs screenshot showing a model hydrograph鈥�
PDM for PCs screenshot showing hydrographs of modelled and observed river flow

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
PDM for PCs: flood peak performance assessment鈥�
PDM for PCs: flood peak performance assessment

Contact for further information

For further information on PDM, please contact Bob Moore via the [email protected] email.

Bob Moore
UK 皇冠体育国际娱乐 for Ecology & Hydrology
Wallingford
OX10 8BB
United Kingdom

Telephone: +44(0)1491 692262

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