Modelling

The Wetland DEM Ponding Model (WDPM) was developed by the Centre for Hydrology at the University of Saskatchewan to model the distribution of runoff water on the Canadian Prairies. The program was originally written in Fortran 95 by Kevin Shook in 2008. Because the program requires many thousands of iterations to converge, it was adapted to CPU parallel processing in 2010 using the OpenMP API .

The current version has been developed to make the program faster and easier to use. The WDPM code was ported from Fortran to C, and a graphical user interface was been added by Oluwaseun Sharomi and Ray Spiteri of the Department of Computer Science at the University of Saskatchewan. The parallel processing now uses
the OpenCL API, which has been found to be faster, and which supports the use of Graphical Processing Units (GPUs). Funding for the recoding of the WDPM was provided by Agriculture and Agri-Food Canada (AAFC).

Version 2.0 of the WDPM was developed in 2020. The GUI now uses Python 3. The program's performance has been improved and many bugs have been fixed. This work was undertaken by Tonghe Liu and Ray Spiteri of the Department of Computer Science.

The purpose of the WDPM is to model the spatial distribution of runoff water on the Canadian Prairies. Because of its recent post-glacial history, the Canadian Prairies do not have a conventional drainage system. When excess water runs off the landscape, generally due to snow melt in the spring, it may trapped in surface depressions ranging in size from puddles to permanent wetlands, and may cause local flooding. If the depressions are full of water, they may connect.

The WDPM was developed to model the spatial distribution of water over a Prairie landscape, as represented by a Digital Elevation Model (DEM). Originally, the purpose of the program was to determine the fractions of Prairie basins contributing flows to streams, as these change dynamically with the storage of water in the depressions. However, the model has also been used to demonstrate the extent of flooding on Prairie landscapes, which may be useful for operational purposes.

Manual
Full details are available in the WDPM User-Guide version 2 (7.89 Mb PDF), available for download here.

Source code
The WDPM is Free Open Source Software (FOSS). You can download the source code directly from GitHub here. Note that you will need to have access to a C compiler and other programs in order to compile the program. WDPM can be compiled for Linux and Windows. Compiling for MacOS may not be successful, due to Apple deprecating OpenCL.

Download compiled program
To download the compiled Windows version of the WDPM, please complete and submit the request form.

Presentations
The following presentations were given at the WDPM launch workshop, held on 19th March 2014;

• John Pomeroy
  Canadian Prairie Hydrology and Runoff Generation
  (10.9Mb PPTX) 
   
• Kevin Shook
  The Wetland DEM Ponding Model
  (896kb PDF) 
   
• Oluwaseun Sharomi & Raymond Spiteri
  Details behind the new WDPM
  (283kb PDF) 
   
• Robert Armstrong
  WDPM Case Studies within the LIRA Framework
  (4.22Mb PDF)