EPIC USERS GUIDE v. 050 9 by Dr. J.R. Williams, Blackland Research and Extension Center, Temple, Texas; Dr. E. Wang, Tarleton State University/Blackland Res. &Ext. Center, Stephenville,Tx; A. Meinardus, Blackland Research and Extension Center, Temple, Texas; Dr. W.L. Harman, Blackland Research and Extension Center, Temple, Texas; Mark Siemers, Center for Agricultural and Rural Development, Iowa State University, Ames; and Dr. Jay D. Atwood, USDA, Natural Resources Conservation Service, Resource Inventory and Assessment. January 2006 2 EPIC Fact Sheet Environment Policy Impact Calculator Contacts: Dr. Jimmy Williams Research Scientist, TAES-Temple, TX Phone: 254-774-6124 Avery Meinardus Programmer I TAES-Temple ,TX Phone: 254-774-6110 Email: [email protected] Todd Campbell, I-EPIC Developer 573 Heady Hall 515-294-9677 [email protected] Model Objective: Assess the effect of soil erosion on productivity. Predict the effects of management decisions on soil, water, nutrient and pesticide movements and their combined impact on soil loss, water quality and crop yields for areas with homogeneous soils and management. Model Components: Weather, surface runoff, return flow, percolation, ET, lateral subsurface flow and snow melt. Water erosion; Wind erosion; N & P loss in runoff , nitrogen leaching; Organic N & P transport by sediment; N & P mineralization, immobilization and uptake; Denitrification; Mineral P cycling; N fixation; Pesticide fate and transport; Soil temperature; Crop growth and yield for over 80 crops; Crop rotations; Tillage, Plant environment control (drainage, irrigation, fertilization, furrow diking, liming); Economic accounting; Waste management (feed yards dairies with or without lagoons). Model Operation: • Daily time step - long term simulations (1-4,000 years). • Soil, weather, tillage and crop parameter data supplied with model. • Soil profile can be divided into ten layers. • Weather generation is optional. Homogeneous areas up to large fields. 3 Management Capabilities: Applications:  1985 RCA analysis  1988 Drought assessment  Soil loss tolerance tool  Australian sugarcane model (AUSCANE)  Pine tree growth simulator  Global climate change analysis  Farm level planning  Drought impacts on residue cover  Nutrient and pesticide movement estimates for alternative farming systems for water quality analysis Users: • NRCS (Temple and other locations)  Universities - Iowa State, Texas A & M, Washington State and others  INRA - Toulouse, France  Other Countries - Australia, Syria, Jordan, Canada, Germany, Taiwan (over ¾ of the world)  USDA, ARS and other research and extension agencies • Universities (Iowa State University, University of Missouri, Texas A&M Contents Overview..................................................................................................................................................... 5 EDITING FILES – USING UTIL .............................................................................................................. 8 UTIL Commands ........................................................................................................................................ 8 MASTER FILE – EPICFILE.dat ................................................................................................................ 9 INPUT FILES ........................................................................................................................................... 10 EPICRUN.DAT ........................................................................................................................................ 11 EPICCONT.dat ......................................................................................................................................... 12 The EPIC Site Files .................................................................................................................................. 16 SOIL****.dat............................................................................................................................................ 18 OPSC****.dat .......................................................................................................................................... 20 WPM1MO.dat .......................................................................................................................................... 22 TILL****.dat ............................................................................................................................................ 24 CROP****.dat .......................................................................................................................................... 26 FERT****.dat ........................................................................................................................................... 33 PEST****.DAT ........................................................................................................................................ 33 MLRN****.dat ......................................................................................................................................... 34 PARM****.dat ......................................................................................................................................... 35 Output and Printing Options PRNT****.dat .......................................................................................................................................... 40 EPIC Output Analyzer .............................................................................................................................. 51 Failed runs ............................................................................................................................................ 53 Problems that may or may not cause failed run .................................................................................... 53 Problems that cause near 0 crop yield .................................................................................................. 53 General problems .................................................................................................................................. 53 Completed runs--examine *.OUT files ................................................................................................. 53 Preliminary investigation .................................................................................................................. 54 Runoff problems--things to check .................................................................................................... 54 Steps to Validate Crop Yields …………………………………………………………………………..65 How to Validate Runoff and Sediment Losses………………………………………………………….67 Pesticide Fate 5 Overview EPIC is a compiled FORTRAN program and therefore a specific format and file structure is crucial. A Universial Text Integrated Language (UTIL) has been developed to support EPIC and help the user to create his or her own data sets. Pressing the F1 key within UTIL provide additional information on each single input variable in EPIC. Most recent developments in EPIC0509 include:  Wind dust distribution from feedlots.  Manure erosion from feedlots and grazing fields.  Optional pipe and crack flow in soil due to tree root growth.  Extend lagoon pumping and manure scraping options.  Enhanced burning operation.  Various slope length/steepness factor estimations.  Carbon pools and transformation equations similar to those in the Century model. Each EPIC run may involve individual EPIC type simulations on separate parcels of land, with the drainage relationships between the parcels specified defined here:  An EPIC study may involve simulations for several sites, each site being a farm, watershed, etc., and each site having an assigned weather station.  Multiple runs may be defined for each site, with alternative weather, soil, or field operation schedule data sets specified for each, e.g, run #1 might have field of corn and soybeans, while run #2 splits field into two sub-areas by defining edge-of-field buffer strip as 2nd sub-area. The data and file structure for EPIC0509 have been changed from previous versions toward a more relational database type format to reduce data duplication of multiple simulation runs. Previous versions duplicated constant weather, soil, and management data in the data file for one or more runs. Now, for a given study, the site, and weather data are only entered once, in site, weather and soil files. A run definition file specifies which site and weather file are used for each run. An overview of the files and data flow is given in Figure 1. For a given study, the major data elements to be developed by a user include descriptions of sites, soils, field operation schedules, weather, and the constant data. The file structure and linkage are now briefly discussed. Runs. The EPICRUN.dat file includes one row of data for each run. Each row of data assigns a run identification number and specifies which site, weather station, soil and tillage operation schedule file will be used for the respective run; this file can be edited with the ―UTIL RUN‖ command. Two weather files may be specified: the weather and wind weather files. If the regular weather and wind station identification parameters are left null, EPIC will use the latitude and longitude data from the filename.sit file and choose a weather station, provided that the files are available and referenced in the WPM1MO.dat and WINDMO.dat files (note: in the following, where filename.* is used, that indicates that the user may supply the file name, with the appropriate * extension; those file names must be listed appropriately in EPICFILE.dat). Constant Data. The EPICCONT.dat file contains parameters that will be held constant for the entire study, e.g., number of years of simulation, period of simulation, output print specification, weather generator options, etc. This file cannot be renamed, but can be edited with the ―UTIL CONT‖ command. 6 Sites. The study may involve several sites (fields, farms, or watersheds). A file named filename.sit is used to describe each site and can be edited by the ―UTIL SITE‖ command. EPICFILE.dat tells EPIC to look in SITE2110.dat (or user chosen name) to reference the numbered list of the sites and their file names. The list of site files in SITE2110.dat can be edited with the ―UTIL SITELIST‖ command and EPICFILE.dat can be edited with the ―UTIL FILE‖ command. Weather. Weather stations are numbered and identified in WPM1MO.dat and wind data for the stations are numbered and identified in WINDMO.dat. EPICFILE.dat tells EPIC to look in WPM1MO.dat (or user chosen name), and WINDMO.dat (or user chosen name) to reference the numbered list of the weather station and their file names. The list of weather stations in WPM1MO.dat can be edited with the ―UTIL WPMLIST‖ command, and the list of wind weather stations in WINDMO.dat can be edited with the ―UTIL WINDLIST‖ command. A file named filename.wp1 is used to describe each weather station statistics and can be edited by the ―UTIL WPM‖ command. Furthermore, a file named filename.wnd is used to describe each wind station statistics and can be edited by the ―UTIL WIND‖ command. Soils. The study may involve several different soils for the farm or watershed analysis. A file named filename.sol is used to describe each subarea and can be edited by the ―UTIL SOIL‖ command. EPICFILE.dat tells EPIC to look in SOIL0509.dat (or user chosen name to reference the numbered list of the soils and their file names). The list of soils can be edited with the ―UTIL SOILLIST‖ command. Operation Schedules. Each field or farm study is described with a unique landuse unit or operation schedule (e.g. crops and crop rotations with typical tillage operations, ponds or reservoir, farmstead with or without lagoon, etc.). Each operation schedule is in a file named filename.ops and may be edited with the ―UTIL OPSC‖ command. Each operation schedule must be numbered and listed in the OPSC0509.dat (or user specified file), which can be edited with the ―UTIL OPSCLIST‖ command. EPICFILE.dat tells EPIC to look in OPSC0509.dat (or user chosen name to reference the numbered list of the operation schedules and their file names. Execution of Runs. EPIC0509 is a compiled Fortran program, which is executed by opening a DOS command prompt window, changing to the directory where the program files have been copied, and typing the command ―EPIC0509‖. Output files (28 per run) Input files: Figure 1: EPIC0509 File Structure Runname.out standard output Runname.acm annual cropman 7 Runname.sum ave annual summary EPICCONT.DAT Runname.dhy daily hydrology Control File, setting parameters that are Runname.dps daily pesticide Runname.mfs monthly flipsim SITE2110.dat (default) constant for entire study or group of runs. Runname.mps monthly pesticide ―UTIL CONT‖ Runname.ann annual Runname.sot ending soil table WPM1MO.dat (default) Runname.dtp daily soil temperature EPICFILE.DAT Runname.mcm monthly cropman (associates 15*.dat file names) Runname.dcs daily crop stress Runname.sco summary operation cost WINDMO.dat (default) Internal File Reference EPIC0509.exe Runname.acn annual soil organic C&N table File Name to be used ―EPIC0509‖ Runname.dcn daily soil organic C&N table ―UTIL FILE‖ Runname.scn summary soil organic C&N CROP2110.dat (default) table Runname.dgn daily general output Runname.dwt daily soil water Site2110.dat (default) EPICRUN.DAT Runname.acy annual crop yield TILL2110.dat (default) List of Sites (Number Run # (one line per run) Runname.aco annual cost and Filename.sit) Site # Runname.dsl daily soil table ―UTIL SITELIST‖ Weather Station # Runname.mwc monthly water N cycle PEST2110.dat (default) Weather Station 1 # Runname.abr annual biomass root weight Runname.atg annual tree growth Wind Weather Station # Runname.msw monthly output to SWAT Filename.sit (one file Soil # Runname.aps Annual pesticide FERT2110.dat (default) per site) Operation Schedule # Runname.dcw daily water cycle ―UTIL SITE‖ ―UTIL RUN‖ (where xxxx is Run #) SOIL2110.dat (default) OPSC2110.dat (default) TR552110.dat (default) OPSC2110.dat SOIL2110.dat WINDMO.dat WPM1MO.dat PARM2110.dat (default) (default) (default) (default) (default) List of Operation List of Soils (Number List of Wind Weather List of Weather Schedules (Number and Filename.sol) Stations (number and Stations (number and and Filename.ops) ―UTIL SOILLIST‖ Filename.wnd) Filename.wp1) MLRN2110.dat (default) ―UTIL OPSCLIST‖ ―UTIL WINDLIST‖ ―UTIL WPMLIST‖ PRNT2110.dat (default) Filename.ops (one Filename.sol (one Filename.wnd (one Filename.wp1 (one file per operation file file per Wind file per Weather schedule) per soil) Weather Station) Station) ―UTIL OPSC‖ ―UTIL SOIL‖ ―UTIL WIND‖ ―UTIL WPM‖ EDITING FILES – USING UTIL UTIL Commands UTIL, a Universial Text Integration Language, is a data file editor that has been developed to help users of large computer models (e.g. EPIC, APEX, SWAT) and other programs (e.g. PHU-program). It is designed to edit any data file with a fixed number of variables, cells or fields and is very easy to use since it combines command-line and full-screen editing. Each variable of each field is provided with a description, the range limits for the variable and a complete interactive help file that completely explains that variable‘s usage (by pressing the F1 key). There may also be extra commands to load blocks of data from data base files for a particular model or application. This greatly speeds data entry in a large data file. All commands used in UTIL are designed to be entered interactively or to be stored in files (UTIL-batch files) to allow groups of commands to be executed in an unattended mode. This technique facilitates the generation of many different scenarios for use in testing computer models. In the following several important UTIL commands are listed and explained: Function Keys: F1 = Interactive help and variable explanation F2 = Analyzing variable of field F3 = Exit UTIL and save data file F4 = Saving data file F5 = Line editing F6 = UTIL statistics F7 = UTIL auto-editing F8 = Quit UTIL without saving data file To start the UTIL program: UTIL FILE EPICFILE.dat <enter> Where: UTIL is the command to execute the UTIL-program. FILE is the name of the driver (i.e., *.drv files) to be used by the UTIL program. The list of drivers for UTIL in EPIC include: FILE, SITELIST, SITE, WINDLIST, WIND, WPMLIST, WPM, CROP, TILL, PEST, FERT, SOILLIST, SOIL, OPSCLIST, OPSC, PARM, MLRN, and PRNT. And EPICFILE.dat is the file name to be loaded which needs to associate with the current driver name in UTIL (e.g. UTIL OPSCLIST OPSC2110.dat <enter>). The file name can be either any default names or any user specified names. Once in UTIL, the user can use some UTIL commands in the command-line such as, LOAD dataset.dat <enter>, or SAVE dataset.dat <enter>, or even run some UTIL-batch files (usually are characterized by the file extension: *.utl). UTIL Batch files are any files, created by the user, that is a list of UTIL commands. These commands could be calculations or repetitive changes to be made to many DATASETs. This file will be opened by UTIL and each line read in as a command to UTIL. An ―@‖ is used to distinguish the BATCH file name from a VARIABLE name in the DATASET or a UTIL command. 9 MASTER FILE – EPICFILE.dat (Components of the EPIC Model) EPIC File Name Links The user must specify the file names to be associated with internal EPIC file references in the EPICFILE.dat file, as shown here in Table 1. As one example of how some of these files are referenced, consider the problem of where the analyst desires to change management after a long period, i.e., 25 years of one system followed by 25 years of another system. Instead of specifying 50 years of tillage operations in an OPSC file, the same effect can be achieved with two runs. The first run will use the first OPSC file and the desired soil file. The second run will use the second OPSC file, but for the soil, will be linked by a soil identification number in the EPICRUN.dat and FSOIL to the EPIC0001.SOT file, which is the final soil table from the first run. The final soil table written by an EPIC run has the identical format to the soil input data files! Table 1: File name references for the EPIC2110 dat file. Internal File Default File UTIL Reference Name (*.dat) Editor Description FSITE SITE0509 SITELIST A numbered list of sites being studied FWPM1 WPM1MO WPMLIST Weather data, ordered by Weather station # FWIND WINDMO WINDLIST Wind data, ordered by Wind Weather station # FCROP CROP0509 CROP Crop parameter file FTILL TILL0509 TILL Parameters for various field operations (machines) FPEST PEST0509 PEST Parameters of pesticides FFERT FERT0509 FERT Parameters of fertilizers FSOIL SOIL0509 SOILLIST List of soil data files FOPSC OPSC0509 OPSCLIST List of available operation schedules FTR55 TR550509 Data for stochastic runoff estimation FPARM PARM0509 PARM Contains equation parameters to be used for the ru FMLRN MLRN0509 MLRN Sets up a multi run ap FPRNT PRNT0509 PRNT Controls printing of output 10 INPUT FILES The input files are discussed in this section along with these supporting data files. The files include: EPICRUN.dat – Determines the number of runs and their configuration by site file #, weather and wind stations, and subarea file #. EPICCONT.dat – Includes input data that does not change between runs included in EPICRUN.dat. SITE****.dat – Lists the site files to be selected in the filename.sit files. Filename.sit – Includes Input Data that does not vary across subarea associated with the site. SOIL****.dat – Lists the soil files to be selected in the filename.sol files. Filename.sol – Includes input data that characterize each soil. OPSC****.dat – Lists the management (operations) files to select from the filename.ops files Filename.ops – Includes input data for each grass, tree, crop or crop rotation produced in the watershed. WPM1MO.dat – Lists the weather station files to select from the filename.wp1 files. Filename.wp1 – Includes weather input data characteristics of each weather station. WINDMO.dat – Lists the wind station files to select from the filename.wnd files. Filename.wnd – Includes wind input data characteristic of each wind station. TILL****.dat – Includes tillage input data by machine. CROP****.dat – Includes crop input data for 47 parameters. FERT****.dat – Includes fertilizer input data by nutrient (note that some commercial fertilizers have potassium in the mix but EPIC does not utilize K20 in the simulated nutrient uptake/yield relationship. MLRN****.dat – Includes the option of selecting consecutive weather needs and water erosion without reloading the inputs. PARM****.dat – Includes numerous model parameters. PRNT****.dat – Includes the control data for printing select output variables in the sections of the EPIC****.out file and 19 other summary files.