Model:PIHM

PIHM

PIHM Questionnaire

Contact Information

Model:	PIHM
Contact person:	Christopher Duffy (Project manager)
Institute:	Penn State University
City:	University Park, Pennsylvania
Country:	USA
Email:	cxd11@psu.edu
2nd person involved:	Mukesh Kumar (Technical contact)
3rd person involved:	Gopal Bhatt (Technical contact)

Model Description

Model type:

Modular model for the hydrological domain.

Description:

PIHM is a multiprocess, multi-scale hydrologic model where the major hydrological processes are fully coupled using the semi-discrete finite volume method. PIHM is a physical model for surface and groundwater, “tightly-coupled” to a GIS interface. PIHMgis which is open source, platform independent and extensible. The tight coupling between GIS and the model is achieved by developing a shared data-model and hydrologic-model data structure.

Technical information

Supported platforms:	UNIX, Linux, Mac OSX, Windows
Programming language:	C, C++,
Model development started at:	2002 and development still takes place
To what degree will the model become available:	Source code, executable.
Current license type:	GPLv2
Memory requirements:	--
Typical run time:	--

Input / Output description

Input parameters:	PIHM is an integrated finite volume hydrologic model. It simulates channel routing, overland flow and groundwater flow in fully coupled scheme. It uses semi-discrete Finite Volume approach to discretize PDE (equations governing physical processes) into ODE to form a system of ODEs and solved with SUNDIALS solver (LBL). PIHM incorporates an object-oriented model data structure which provides extensibility and efficient storage of data at the same time. PIHM v2.0 requires the following input files: projectName.txt : This file will have the project name as its content. .mesh File : Spatial information of Nodes and Irregular Meshes (TINs) .att File : Attribute defining different classes an element belongs to .soil File : Soil properties .geol : Geologic properties .lc file : Vegetation parameters of different land cover types .riv file : Spatial, geometry and material information of river segments .forc file : All the forcing variables (forcing time-series) .ibc file : Boundary condition information for elements .para file : Control parameters (solver options; model modes; error control) .init : If initial condition input is through a file .calib : Calibration parameters and process controls
Input format:	ASCII and shapefile
Output parameters:	PIHM v2.0 uses Net_CDF for state and flux output. Details are under development (April 2009) and will be complete July 2009
Output format:	ASCII Net_CDF
Post-processing software (if needed):	No, PIHM and PIHM_GIS incorporates an object-oriented model data structure which provides extensibility and efficient storage of data at the same time. The output is stored in NET_CDF and we are currently implementing VISIT as the basic tool. VISIT will also be implemented within the PIHM_GIS interface July 2009
Visualization software (if needed):	Yes, any software able to visualize gridded data (RiverTools / 3DEM)

Process description

Processes represented by model:	The Penn State Integrated Hydrologic Model (PIHM) is a fully coupled multiprocess hydrologic model. Instead of coupling through artificial boundary conditions, major hydrological processes are fully coupled by the semi-discrete finite volume approach. For those processes whose governing equations are partial differential equations (PDE), we first discretize in space via the finite volume method. This results in a system of ordinary differential equations (ODE) representing those procesess within the control volume. Within the same control volume, combining other processes whose governing equations are ODE’s, (e.g. the snow accumulation and melt process), a local ODE system is formed for the complete dynamics of the finite volume.
Key physical parameters & equations:	Processes include: 2-D overland flow, 2-D groundwater flow, 1-D soil moisture, 1-D channel flow, snow/melt, et, vegetation water use by NLCD,
Length scale & resolution constraints:	typically based on original DEM used to develop the watershed model
Time scale & resolution constraints:	fully implicit, time adaptive, based on the CVODE ODE solver from LBL
Numerical limitations and issues :	Solver is efficient and accurate for very stiff systems of equations

Testing

Available calibration data sets:	Upper Juniata River 875 km^2: see: http://sourceforge.net/projects/pihmmodel/
Available test data sets:	Upper Juniata River 875 km^2: see: http://sourceforge.net/projects/pihmmodel/
Ideal data for testing:	PIHM is a distributed watershed model that can represent surface/subsurface processes at scales ranging from a few hundred m^2 to 10,000 km^2. However, large systems will require the parallel version currently under development

User groups

Currently or plans for collaborating with:

We have several other extensions to PIHM under development: solute transport, sediment transport, 3-D Richard's Equation. Full information can be found at: http://sourceforge.net/projects/pihmmodel/

Documentation

Key papers of the model:	Qu Y., C. J. Duffy (2007), A semidiscrete finite volume formulation for multiprocess watershed simulation, Water Resour. Res., 43, W08419, doi:10.1029/2006WR005752. Kumar, M., G. Bhatt, and C.J. Duffy, 2008, The Role of Physical, Numerical and Data Coupling in a Mesoscale Watershed Model, Advances in Water Resources. under review April. 2009 Kumar, M., G. Bhatt, and C.J. Duffy, 2008, An efficient domain decomposition framework for accurate representation of geodata in distributed hydrologic models, International Journal of Geographical Information Science, IJGIS-2008-0069.R1 Kumar, M. C. J. Duffy, 2008, Object Oriented Shared Data Model for GIS and Distributed Hydrologic Models, Journal of International Journal Geographical Information Science, Accepted July 2008.
Is there a manual available:	Yes
Model website if any:	http://www.pihm.psu.edu/pihmgis_downloads_v2.0.0.html

Additional comments

Comments:

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Download

See http://sourceforge.net/projects/pihmmodel/

Source

See http://sourceforge.net/projects/pihmmodel/