Probability Distributed Model (PDM)
Simulations using PDM functionality can only be run if the PDM option is enabled on your licence.
The Probability Distributed Model (PDM) is a general-purpose, lumped conceptual model for continuous rainfall-runoff simulation (Moore, 2007). The PDM model incorporated within InfoWorks ICM is based on the model developed by the UK Centre for Ecology and Hydrology (CEH) © 2000 NERC CEH Wallingford.
General form of the PDM rainfall-runoff model
Using the PDM model
To use the PDM runoff volume model, set the Runoff volume type field of the Runoff surface to PDM.
Subcatchments referencing a PDM runoff surface must also reference a PDM Descriptor object. The descriptor is used to define the PDM rainfall-runoff model parameters.
A PDM Descriptor's parameters can be automatically calibrated using observed rainfall, flow, potential evaporation and temperature from a time series database (TSDB) to optimise the values used by the PDM descriptor.
Using the PDM model for warming up the network
The PDM model can also be used to warm-up the network before any hydraulic simulations are run. This allows it to reach a steady state and thus provide more realistic hydraulic conditions when a simulation starts. See Schedule Hydraulic Run View for further information.
