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Soil - Plant - Atmosphere - Water Field & Pond Hydrology

posted on 2024-02-09, 17:54 authored by Keith Saxton

SPAW is a daily hydrologic budget model for agricultural fields and ponds (wetlands, lagoons, ponds and reservoirs). Included are irrigation scheduling and soil nitrogen. Data input and results are graphical screens.

The SPAW (Soil-Plant-Air-Water) computer model simulates the daily hydrologic water budgets of agricultural landscapes by two connected routines, one for farm fields and a second for impoundments such as wetland ponds, lagoons or reservoirs. Climate, soil and vegetation data files for field and pond projects are selected from those prepared and stored with a system of interactive screens. Various combinations of the data files readily represent multiple landscape and ponding variations.

Resources in this dataset:

  • Resource Title: Soil Water Characteristics - Equations.

    File Name: Soil Water Characteristics-Equations.xls

  • Resource Title: Instructions for Access to USDA / NRCS Soils Data.

    File Name: Accessing USDA Soils Data.pdf

  • Resource Title: Evaporation default files for USA.

    File Name: SPAW Evaporation Default

    Resource Description: These *.djvu files require a free reader plug-in available from :





Data contact name

Parry, Rob

Data contact email


USDA Agricultural Research Service


  • Not specified

Geographic Coverage


Geographic location - description

United States

ISO Topic Category

  • biota
  • climatologyMeteorologyAtmosphere
  • environment
  • farming
  • geoscientificInformation
  • inlandWaters

National Agricultural Library Thesaurus terms

water balance; models; ponds; wetlands; irrigation scheduling; soil; nitrogen; computer software; computer simulation; agricultural land; farms; climate; vegetation; landscapes; rain; temperature; evaporation; soil profiles; annuals; irrigation; water budget; runoff; evapotranspiration; soil water; wastewater; water supply; crop production; Agricultural Research Service; Washington (state); drainage; Natural Resources Conservation Service; Oregon; agricultural watersheds; stream flow; animal housing; drawdown; pumps; water table; waterfowl; salinity; chemistry; screening; soil surveys; United States; agricultural management; simulation models; conservation practices; soil morphology; algorithms; soil classification; soil matric potential; water holding capacity; soil texture; gravel; soil salinity; organic matter

OMB Bureau Code

  • 005:18 - Agricultural Research Service

OMB Program Code

  • 005:040 - National Research

ARS National Program Number

  • 211

Pending citation

  • No

Public Access Level

  • Public

Preferred dataset citation

Saxton, Keith (2017). Soil - Plant - Atmosphere - Water Field & Pond Hydrology. USDA Agricultural Research Service.