WARMF

WARMF (Watershed Analysis Risk Management Framework)

Criterion

Explanation

General Description

Watershed Analysis Risk Management Framework (WARMF) is a watershed model and decision support system that simulates the physical, chemical, and biological processes in a watershed and provides scientific information to stakeholders. The graphical user interface guides stakeholders to develop and evaluate water quality management alternatives for a basin. WARMF has a comprehensive simulation engine that simulates watershed physical processes on a daily or shorter time step. The model can track approximately 40 water quality constituents from precipitation and dry deposition through vegetation canopy, land surface, soil layers, river segments, and stratified reservoirs. The model website is at:  http://systechwater.com/warmf_software/

Model Domain

The model domain is flexible and can be specified by the user; it includes watersheds as a network of linked land catchments, river segments, and lakes.

Developer

Electric Power Research Institute, currently supported by Systech Water Resources

Hardware computing requirements

Windows compatible PC

Code language

Technical code – FORTRAN; GUI – C++

Original application

WARMF was designed to be a decision support system to support watershed analysis and TMDL calculations for urban applications. It simulates watersheds as a network of linked land catchments, river segments, and lakes. It uses meteorological data to dynamically simulate runoff and nonpoint source loads from land.

Public/proprietary and cost

WARMF is public domain software, and available for download from the Systech website.

Physically or empirically based

WARMF is a physically based model.

Mathematical methods used

  • Runoff: mass balance of precipitation, interception, evapotranspiration, infiltration, and percolation
  • Infiltration: modeled as a function of the available water in the layer (difference between soil moisture and field capacity) and accounts for exfiltration based on Darcy's Law
  • Flow Routing: unknown
  • Water Quality: pollutant buildup and wash-off calculations are adapted from SWMM code, sediment erosion from ANSWERS model code and the universal soil loss equation

Input data requirements

Spatial data: DEM, stream network, soil, land use, septic systems, and point sources. Flow and water quality data for calibration. Coefficient data of physical data, meteorology (snow, evaporation), land use, land application, irrigation, sediment transport, BMPs, septic systems, chemical and biological reactions of pollutants, soil layers.

Outputs

The model predicts daily flow and water quality variables including pH, temperature, DO, ammonia, nitrate, phosphate, suspended sediment, bacteria, cations, anion, algal species, periphyton, and metals such as iron, zinc, manganese, and copper. Pollutant loads. For stratified lakes, WARMF provides two options: 1D (vertically stratified) and 2D (using CE-QUAL-W2). Binary files are written for the GUI to display, but the model can also output text files for post-processing.

Pre-processing and post-processing tools

The model has a built-in GUI for pre- and post-processing.

Representation of uncertainty

Stochastic model runs /sensitivity analysis can be used to evaluate model uncertainty.

Prevalence

The model has been used for research purposes, and for water quality forecasting and TMDL applications. Less commonly used than other watershed models such as SWAT and HSPF.

Ease of use for public entities

The model requires a moderate amount of training and set-up time.

Ease of obtaining information and availability of technical support

Technical support is available from Systech Water Resources.

Source code availability

The Fortran code is only available for review upon request from Systech.  Source code is not in public domain.

Status of model development

The model is available for immediate use. The future direction of model updates is unknown.

Challenges in integration

The model runs on an hourly time step and output can be exported to text files. Time series output shows simulation results (water quality and/or hydrology) for specified locations over the time period of the model simulation. Challenges may occur if other models do not provide the same amount of information at the hourly time step. WARMF does not simulate subsurface water quality which is a serious limitation for use on Delta islands.

Model inventory developed for Delta Stewardship Council Integrated Modeling Steering Committee (IMSC)