1. General Model Information

Name: integrated model for transport of nonpoint-source pollutants

Acronym: OPUS

Main medium: air+terrestrial
Main subject: hydrology
Organization level: Ecosystems
Type of model: partial differential equations (finite differences)
Main application:
Keywords: infiltration, runoff, soil water, non-point source pollution, erosion, precipitation change, temperature change, hydrology, transport,


Roger E. Smith
United States Department of Agriculture
Agricultural Research Service,
Water Management Research Unit
CO 80522 Fort Collins
Fax :
email: roger@lily.aerc.colostate.edu


Roger E. Smith


contents of the model
Opus (not an acronym) is a computer model for the transport of material in soil and surface water within and from a small catchment. The model is a simulation tool for studying the potential pollution from various agricultural management practices. It simulates water movement theat results from rainfall and other weather inputs and that is affected by soil, crop, topography, and many types of management actions and water use influencing the surface conditions. Opus includes models for the growth of plants, development of cover, water use, uptake of nutrients, cycling of soil nitrogen, phosphorus, and carbon, transport of adsorbed pesticides and nutrients, interaction of surface water and soil water, runoff and erosion.
principles of the model
The model operates on a basic daily cycle of simulations, with an accounting cycle of one year for purposes of summaries. It allows the user to choose between a) detailed simulation involving data on the time-intensity pattern of rainfall and b) a more lumped approach using either recorded daily rainfall or stochastically generated rainfall.

II. Technical Information

II.1 Executables:

Operating System(s): DOS Type of computer: PC

II.2 Source-code:

Programming Language(s): FORTRAN

II.3 Manuals:

Manual: Ferreira, V.F. and Smith, R.E.: Opus: An Integrated Simulation Model for Transport of Nonpoint Source Pollutants at the Field Scale, Vol. II, User manual, ARS, 98, USDA-ARS (1992), pp. 200. Complete model documentation: Smith, R.E.: Opus: An integrated simulation model for transport of nonpoint-source pollutants at the field scale, VOL: I, Documentation, ARS, 98, USDA-ARS (1992), pp. 120.

II.4 Data:

III. Mathematical Information

III.1 Mathematics

This is a list of model equations sorted by their characteristics with hypertext links for more details.

III.2 Quantities

This is a list of model quantities sorted by their characteristics with hypertext links for more details.

III.2.1 Input

III.2.2 Output

IV. References

Bennet, J.P., 1974.Concepts of mathematical modeling of sediment yield Water Resources Research 10, 299-303.

Bouwer, H., Van Schilfgaarde, J., 1963.Simplified method of predicting fall of water table in drained land Transact. of Amerik. Soc. of Agr. Eng., 288-291.

Brooks, R.H.; Corey, A.T., 1964.Hydraulic properties of porous media.
Hydrology Paper 3, Colorado State University, Fort Collins, Colorado, pp. 22-27.

Chevalier, B.E., 1984.The hydraulic effects of surface layer development on an unprotected soil due to rainfall energy M.S. Thesis, Department of Civil Engineering, Colorado State University.

De Vries, D.A., 1966.Thermal properties of soils, chapter 7 Physics of Plant Environment, Van Wijk, W.R., Amsterdam, pp. 210-230.

Foster, G.R., 1982.Modeling the erosion process, chapter 8 Hydrologic Modeling of Small Watersheds, Haan, C.T. et al., pp. 297-388.

Foster, G.R., Lane, L.J., Nowlin, J.D., 1980.A model to estimate sediment yield from field-sized areas: Selection of parameter values,chapter 2 CREAMS II, 193-281.

Foster, G.R., Johnson, C.B., Moldenhauer, W.C., 1982.Hydraulics of failure of unanchored cornstalk and wheat straw mulches for erosion control Transact. of Americ. Soc. of Agrig. Eng., 940-947.

Foster, G.R., Smith, R.E., Knisel, W.G., Hakonson, T.E., 1983.Modeling the effectiveness of on-site sediment controlAmerican Soc.of Agricultural Engineers, 15pp.

Foster, G.R., Young, R.A., Niebling, W.H., 1985.Sediment composition for nonpoint source pollution analysis Transact. of Americ. Soc. of. Agr. Eng., 133-139.

Linsley, R.K., Kohler, M.A., Paulus, J.H., 1958.Runoff relations, chapter 8 Hydrology for Engineers, 340pp.

Morris, E.M., Woolisher, D.A., 1980.Unsteady one-dimensional flow over a plane: Partial equilibrium and recession hydrographs Water Resources Research 16, 355-360.

Parton, W.J., Mosier, A.R., Schimel, D.S., 1988.Rates and pathways of nitrous oxide production in a shortgrass steppe Biogeochemisstry 6, 54-58.

Parton, W.J., Schimel, D.S., Cole, C.D., Ojima, D.S., 1987.Analysis of factors controlling soil organic matter levels in great plains grasslands Soil Science Society of America Journal, 1173-1179.

Parton, W.J., Stewart, J.W.B., Cole, C.V., 1988.Dynamics of C, N, P and S in grassland soils: A modelBiogeochemistry (1988), 109-131.

Pinck, L.A., Allison, F.E., Sherman, M.S., 1950.Maintenance of soil organic matter: II. Losses of carbon and nitrogen from young and matureplant material during decomposition in soil Soil Science 69, 391-401.

Richardson, C.S., 1981.Stochastic simulation of daily precipitation, temperature, and solar radiationWater Resources Research 17, 182-190.

Richardson, C.W., Wright, D.A., 1984.A model for generating daily weather variables Department of Agriculture, pp. 83pp.

Ritchie, J.T., 1972.A model for predicting evaporation from a row crop with incomplete cover Water Resour. Res. 8(5) (1972), 1204-1213.

Schrieber, J.D., 1990.Estimating soluble phosphorus from green crops and their redidues in agricultural runoff Small Watershed Model (SWAM), DeCoursey, D.G., pp. 77-95.

Smith, R.E., 1981.Rational models of infiltration hydrodynamics Water Resources Publications, Singh, V.P., Littleton, pp. 107-126.

Smith, R.E., 1990.Analysis of infiltration into a two-layer soil profile Soil Science Society of America Journal, 1219-1227.

Smith, R., and V. Ferreira. 1992. Opus: an integrated simulation model for transport of non-pointsource pollutants at the field scale. USDA-ARS publication ARS-98, Ft.Collins, Colorado.

Smith, R.E., 1983.Approximate soil water movement by kinematic characteristics Soil Science Society of America Journal, 3-8.

U.S. Department of Agriculture, Soil Conservation Service, 1972.Estimation of direct runoff from storm rainfall, chapter 10 National Engineering Handbook, 10.1-10.24.

U.S. Department of Agriculture, 1980.A field scale model for chemicals, runoff, and erosion from agricultural management systems Conservation Report No 26, 640pp.

van Genuchten, M.T., 1980.A closed form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Science Society of America Journal 44, 892-898.

Walker, A., 1974.A simulation model for prediction of herbicide persistence Journal of Environmental Quality, 396-401.

Williams, J.R., 1975.Sediment yield prediction with universal equation using runoff energy factorAgricultural Research Service ARS-S-40, U.S. Department of Agriculture, pp. 244-252.

Williams, J-R., Berndt, H.D., 1977.Sediment yield prediction based on watershed hydrology Transactions of Americ. Soc. of Agr. Eng, 1100-1104.

Williams, J.R., Jones,C.A., Dyke, P.T., 1984.A modeling approach to determining the relationship between erosion and soil productivityTransactions of Am. Soc. of Agr. Eng., 129-144.

Wischmeier, W.H., Smith, D.D., 1978.Predicting rainfall erosion losses: A guide to conservation planning Agriculture Handbook No 537, U.S. Department of Agriculture, pp. 58pp.

V. Further information in the World-Wide-Web

VI. Additional remarks

Additional information
Last review of this document by:
Status of the document: last modified by T. Gabele Wed Nov 11 17:42:50 MET 1998
last modified by T. Gabele Wed Aug 21 21:44:46 CEST 2002

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