Soil & Water Assessment Tool - swat.tamu.edu

1 Soil & Water Assessment Tool input / output Documentation Version 2012. Arnold, Kiniry, R. Srinivasan, Williams, Haney, Neitsch Texas Water Resources Institute TR-439. CONTENTS. CHAPTER 1. OVERVIEW 1. WATERSHED CONFIGURATION 2. SUBBASINS 2. HYDROLOGIC RESPONSE UNITS 2. REACH/MAIN CHANNELS 4. TRIBUTARY CHANNELS 4. PONDS/WETLANDS/RESERVOIRS 4. POINT SOURCES 5. OVERVIEW OF input FILES 6. MODEL INPUTS BY TYPE 9. CHAPTER 2. SWAT input : WATERSHED CONFIGURATION 31. DISCRETIZATION SCHEMES 32. WATERSHED CONFIGURATION FILE (.FIG) 32. INCORPORATION OF COMMENTS 33. COMMAND LINES 33. REFERENCES 59. CHAPTER 3. SWAT input : 63. TITLE SECTION 64. GENERAL INFORMATION/WATERSHED CONFIGURATION 64. CLIMATE 65. WATERSHED MODELING OPTIONS 72. DATABASE FILES 73. SPECIAL PROJECTS 74. output INFORMATION 75. CHAPTER 4. SWAT input .

2 BSN 89. TITLE 90. MODELING OPTIONS: LAND AREA 90. Water BALANCE 90. SURFACE RUNOFF 97. NUTRIENT CYCLING 100. PESTICIDE CYCLING 106. ALGAL/CBOD/DISSOLVED OXYGEN 106. BACTERIA 107. MODELING OPTIONS: REACHES 110. SUBDAILY EROSION 117. SUBBASIN DRAINAGE 118. CHAPTER 5. SWAT input : .SUB 125. CHAPTER 6. SWAT input : .PCP 139. DAILY PRECIPITATION DATA 140. SUB-DAILY PRECIPITATION DATA 142. CHAPTER 7. SWAT input : .TMP 147. CHAPTER 8. SWAT input : .SLR 151. CHAPTER 9. SWAT input : .WND 155. CHAPTER 10. SWAT input : .HMD 159. CHAPTER 11. SWAT input : .PET 163. CHAPTER 12. SWAT input : .WGN 165. CHAPTER 13. SWAT input : .CST 179. CHAPTER 14. SWAT input : 187. CHAPTER 15. SWAT input : 213. CHAPTER 16. SWAT input : 215. CHAPTER 17. SWAT input : 221. CHAPTER 18. SWAT input : 225. CHAPTER 19. SWAT input : .HRU 231. TITLE 232. TOPOGRAPHIC CHARACTERISTICS 232.

3 LAND COVER CHARACTERISTICS 233. Water CYCLING 235. EROSION 236. DEPRESSIONAL STORAGE AREA/POTHOLE 235. URBAN BMP REDUCTIONS 239. CHAPTER 20. SWAT input : .MGT 243. GENERAL MANAGEMENT VARIABLES 244. INITIAL PLANT GROWTH PARAMETERS 244. GENERAL MANAGEMENT PARAMETERS 245. URBAN MANAGEMENT PARAMETERS 251. IRRIGATION MANAGEMENT PARAMETERS 252. TILE DRAIN MANAGEMENT PARAMETERS 254. MANAGEMENT OPERATIONS 256. SCHEDULED MANAGEMENT OPERATIONS 257. PLANTING/BEGINNING OF GROWING SEASON 260. IRRIGATION OPERATION 263. FERTILIZER APPLICATION 266. PESTICIDE APPLICATION 268. HARVEST & KILL OPERATION 269. TILLAGE OPERATION 271. HARVEST OPERATION 273. KILL OPERATION 276. GRAZING OPERATION 277. AUTO IRRIGATION INITIALIZATION 279. AUTO FERTILIZER INITIALIZATION 284. STREET SWEEPING OPERATION 287. RELEASE/IMPOUND OPERATION 290.

4 CONTINUOUS FERTILIZER OPERATION 291. CONTINUOUS PESTICIDE APPLICATION 293. BURN OPERATION 295. SKIP A YEAR OPERATION 296. CHAPTER 21. SWAT input : .WUS 297. CHAPTER 22. SWAT input : .SOL 301. CHAPTER 23. SWAT input : .CHM 317. CHAPTER 24. SWAT input : .GW 323. CHAPTER 25. SWAT input : .RTE 331. CHAPTER 26. SWAT input : .WWQ 345. CHAPTER 27. SWAT input : .SWQ 353. CHAPTER 28. SWAT input : .PND, .DPD, .WPD, .RIB, .SFB 365. POND FILE (.PND) 366. DETENTION POND FILE (.DPD) 377. WET POND FILE (.WPD) 379. RENTENTION-IRRIGATION BASIN FILE (.RIB) 381. SEDIMENTATION-FILTRATION BASIN FILE (.SFB) 383. CHAPTER 29. SWAT input : .RES 393. RESERVOIR FILE 394. DAILY RESERVOIR OUTFLOW FILE 405. MONTHLY RESERVOIR OUTFLOW FILE 405. CHAPTER 30. SWAT input : .LWQ 407. CHAPTER 31. SWAT input : MEASURED 419. HOURLY RECORDS (RECHOUR) DATA FILE 420.

5 DAILY RECORDS (RECDAY) DATA FILE 423. MONTHLY RECORDS (RECMON) DATA FILE 426. YEARLY RECORDS (RECYEAR) DATA FILE 430. AVERAGE ANNUAL RECORDS (RECCNST) DATA FILE 434. CHAPTER 32. SWAT output FILES 437. input SUMMARY FILE ( ) 438. STANDARD output FILE ( ) 438. HRU output FILE ( ) 448. SUBBASIN output FILE ( ) 458. MAIN CHANNEL output FILE ( ) 461. HRU IMPOUNDMENT output FILE ( ) 466. RESERVOIR output FILE ( ) 457. SEDIMENT LOADS output FILE ( ) 475. MANAGEMENT output FILE ( ) 477. SOIL output FILE ( ) 479. SNOW AT ELEVATION BAND output FILE. ( ) 479. PESTICIDE output FILE ( ) 480. HOURLY output FILE ( ) 481. CHANNEL VELOCITY output ( ) 481. Water DEPTH output FILE ( ) 482. CARBON output FILE ( ) 482. CHAPTER 33. SWAT input : .OPS 485. SCHEDULED MANAGEMENT OPERATIONS 486. TERRACING 487. TILE DRAINAGE 489.

6 CONTOURING 490. FILTER STRIPS 491. STRIP CROPPING 492. FIRE OPERATION 493. GRASSED WATERWAYS 494. PLANT PARAMETER UPDATE 496. CHAPTER 34. SWAT input : SEPTWQDB 501. CHAPTER 35. SWAT input : .SEP 511. CHAPTER 36. SWAT input : 521. ATMOSPHERIC DEPOSITION FILE 522. ATMOSPHERIC DEPOSITION OF NUTRIENTS 523. CHAPTER 37. SWAT input : 533. LANDUSE UPDATE FILE ( ) 534. DESCRIPTION OF FNAM input FILE 535. CHAPTER 38. SWAT input : .SNO 537. CHAPTER 39. SWAT input : .SDR 543. CHAPTER 40. SWAT ROUTING UNIT DATA: .RU 545. APPENDIX A. MODEL DATABASES 563. LAND COVER/PLANT GROWTH DATABASE 564. LAND COVER/PLANT TYPES IN DATABASE 567. TEMPERATURE RESPONSES 567. LEAF AREA DEVELOPMENT 571. ENERGY-BIOMASS CONVERSION 575. LIGHT INTERCEPTION 581. STOMATAL CONDUCTANCE 583. CANOPY HEIGHT/ROOT DEPTH 584. PLANT NUTRIENT CONTENT 588.

7 HARVEST 591. USLE C FACTOR 595. RESIDUE DECOMPOSITION 595. MINIMAL LAI/BIOMASS DURING DORMANCY 596. TILLAGE DATABASE 597. PESTICIDE DATABASE 600. Water SOLUBILITY 606. SOIL ADSORPTION COEFFICIENT 606. SOIL HALF LIFE 606. FOLIAR HALF LIFE 607. WASH-OFF FRACTION 607. APPLICATION EFFICIENCY 607. FERTILIZER DATABASE 608. COMMERCIAL FERTILIZERS 609. MANURE 610. URBAN DATABASE 612. DRAINAGE SYSTEM CONNECTEDNESS 613. CURB LENGTH DENSITY 614. WASH-OFF COEFFICIENT 614. MAXIMUM SOLID ACCUMULATION & RATE OF ACCUMULATION 614. NUTRIENT CONCENTRATION IN SOLIDS 616. CURVE NUMBER 617. APPENDIX B. EXAMPLE WATERSHED CONFIGURATIONS 623. SUBWATERSHED DISCRETIZATION 624. SUBWATERSHED DISCRETIZATION: 3 SUBBASINS 625. SUBWATERSHED DISCRETIZATION: SAVING RESULTS FOR. DOWNSTREAM RUNS 628. SUBWATERSHED DISCRETIZATION: INCORPORATING POINT.

8 SOURCE/UPSTREAM SIMULATION DATA 629. SUBWATERSHED DISCRETIZATION: INCORPORATING. RESERVOIRS 630. SUBWATERSHED DISCRETIZATION: SAVING SIMULATION. RESULTS FOR ONE LOCATION 631. HILLSLOPE DISCRETIZATION 632. HILLSLOPE DISCRETIZATION: MODELING A DAIRY. OPERATION 633. HILLSLOPE DISCRETIZATION: COMBINING WITH. SUBWATERSHED DISCRETIZATION 642. GRID CELL DISCRETIZATION 646. GRID CELL DISCRETIZATION: 9 CELLS 646. CHAPTER 1. SWAT input DATA: OVERVIEW. SWAT is a comprehensive model that requires a diversity of information in order to run. Novice users may feel a little overwhelmed by the variety and number of inputs when they first begin to use the model. However, many of the inputs are used to simulate special features that are not common to all watersheds. This chapter provides an overview of model inputs. The inputs are organized by topic and emphasis is given to differentiating required inputs from optional inputs.

9 This chapter focuses on assisting the user in identifying inputs that must be defined for their particular dataset. The remaining chapters list variables by file and discuss methods used to measure or calculate values for the input parameters. 1. 2 SWAT input / output FILE DOCUMENTATION, VERSION 2012. WATERSHED CONFIGURATION. The first step in setting up a watershed simulation is to partition the watershed into subunits. SWAT allows several different subunits to be defined within a watershed. Subbasins unlimited number of HRUs (1 per subbasin required). one pond (optional). one wetland (optional). Reach/main channel segments (1 per subbasin). Impoundments on main channel network (optional). Point sources (optional). SUBBASINS. The first level of subdivision is the subbasin. Subbasins possess a geographic position in the watershed and are spatially related to one another, outflow from subbasin #5 enters subbasin #7.

10 The subbasin delineation may be obtained from subwatershed boundaries that are defined by surface topography so that the entire area within a subbasin flows to the subbasin outlet. Alternatively, the subbasin delineation may be obtained from grid cell boundaries. Since most spatial input is grid-based ( DEM, NEXRAD, LULC), grid cells are an appealing approach for subbasin delineation. However unlike the subwatershed discretization, grid cells do not preserve routing reaches and topographic flow paths. A subbasin will contain at least one HRU, a tributary channel and a main channel or reach. Two types of impoundments, a pond and/or wetland, may also be defined within a subbasin. These features are reviewed in the following sections. HYDROLOGIC RESPONSE UNITS. The land area in a subbasin may be divided into hydrologic response units (HRUs).