Community Modeling and Analysis System


Generate agricultural land nitrogen and soil information for CMAQ bi-directional NH3 modeling and provide edge of field inputs for SWAT watershed hydrology and water quality modeling

The Fertilizer Emission Scenario Tool for CMAQ (FEST-C v1.4) is a Java-based interface system that facilitates the integration of agriculture, atmosphere, and hydrology simulations at large scales through the current release of the Spatial Allocator (SA v4.3.2) Raster Tools system. With an adapted Environmental Policy Integrated Climate (EPIC) model for grassland and crop production, the system is primarily used to simulate daily soil carbon (C), nitrogen (N), and phosphorus (P) cycles on agricultural lands with atmospheric conditions and management practices including fertilization and irrigation. The FEST-C interface with simple tool buttons guides users through EPIC simulations and output extractions to generate the required input for CMAQ bi-directional NH3 modeling. In addition to its application for air quality modeling, the system has been enhanced to integrate with the Soil and Water Assessment Tool (SWAT) for watershed hydrology and water quality assessment. FEST-C enables the extraction of SWAT-ready input files with nutrient and water runoff from agricultural lands and weather and N deposition from atmospheric models for simulating nitrogen fate and transport in watersheds.


Java-based FEST-C interface with 14 tools to:

  • Build required input database of 21 crops for EPIC simulations over a given CMAQ domain
  • Simulate soil N conditions with fertilization and irrigation based entirely on simulated plant demand in response to local soil and weather conditions using EPIC,
  • Perform EPIC to CMAQ and EPIC/WRF/CMAQ to SWAT extraction, and
  • Visualize simulated results spatially.

EPIC Modeling system including:

  • EPIC model version 0509 from Texas A&M University (TAMU) modified by EPA for CMAQ and SWAT requirements,
  • Utility programs to build input data sets and analyze and extract output,
  • Common data sets (e.g. weather station climate statistic files and built soil data files) for EPIC modeling,
  • Scenarios which contain a test case and to store users' application scenarios, and
  • Documentation of the EPIC development for CMAQ in the FEST-C.


  • Follow the documentation for installation
  • FEST-C works for CMAQ domains over US at different resolutions and in any of the WRF/CMAQ projection coordinate systems

Updates in Version 1.4

  • Added the EPIC/WRF/CMAQ to SWAT capabilities
  • Improved EPIC C-N cycle and hydrology processes
  • Modified EPIC parameter and condition input files for regional applications
  • Improved management file generation for EPIC
  • Modified EPIC output for CMAQ and SWAT requirements
  • Updated 5-year average CMAQ N deposition data sets
  • Updated interface and all related tools including Spatial Allocators Raster Tools
  • Added more R utility tools for analysis and extraction
  • Fixed bugs in interface and EPIC

Latest Version: FEST-C version 1.4



Hands-on FEST-C training will become available to the community in the near future.


Online Resources

  • Cooter et al. 2010: Estimation of NH3 bi-directional flux from managed agricultural soils, Atmos. Envi.
  • Ran et al. 2011: Development of an Agricultural Fertilizer Modeling System for Bi-directional Ammonia Fluxes in the CMAQ Model, 31th ITM paper.
  • Cooter et al. 2012: Linking agricultural crop management and air quality models for regional to national-scale nitrogen assessments, Biogeosciences.
  • Pleim et al. 2013: Development and evaluation of an ammonia bidirectional flux parameterization for air quality models, JGR-Atmosphere.
  • Bash et al. 2013: Evaluation of a regional air-quality model with bidirectional NH3 exchange coupled to an agroecosystem model, Biogeosciences.
  • 2013 Talk by Cooter et al.: FEST-C for Bi-directional CMAQ: Update
  • 2016 Talk by Cooter et al.: Enhancements to an Agriculture-land Modeling System - FEST-C and Its Applications

Previous Documentation

System Requirements

O/S Linux 64-bit x86
Software Spatial Allocator v4.3.2, VERDI
Compilers Intel Fortran for EPIC, GCC for SA Raster Tools


History of FEST-C

  • FEST-C V1.4 (09/20/2018) - Updated release
  • FEST-C V1.3 (06/30/2017) - Updated release
  • FEST-C V1.2 (05/31/2016) - Updated release
  • FEST-C V1.2 (02/09/2016) - Updated release
  • FEST-C V1.2 (09/30/2015) - Updated release
  • FEST-C V1.1 (05/30/2014) - Updated release
  • FEST-C V1.0 (10/25/2013) - First release

The development of the system has been funded by the EPA. The creation of the FEST-C interface and EPIC application was driven by the 2012 release of the bi-directional NH3 option for CMAQ. While there are other EPIC model user interfaces, FEST-C has been specifically designed to require minimal user inputs and to produce bi-directional CMAQ-ready output files for any CMAQ domain and grid cell resolution for which MCIP data is available.