Nonpoint‐Pollution Model Sensitivity to Grid‐Cell Size
Publication: Journal of Water Resources Planning and Management
Volume 119, Issue 2
Abstract
Nonpoint‐pollution models estimate loadings of chemicals, sediment, and nutrients that degrade water quality. Before controls can be implemented, location and severity of pollution must be identified in the watershed basin. Geographic information systems (GISs) are computer‐automated, data management systems simplifying the input, organization, analysis, and mapping of spatial information. Because nonpoint‐pollution models simulate distributed watershed basin processes, a heterogeneous and complex land surface must be divided into computational elements such as grid cells. Model parameters can be derived from each grid cell directly from maps using GIS. Cell size selection, if arbitrarily determined though, yields ambiguous if not erroneous results. This paper investigates the effects of cell size selection through a sensitivity analysis of input parameters for the nonpoint‐pollution model, Agricultural Nonpoint Source Pollution Model (AGNPS), using a GIS for a small research watershed. Model grid‐cell sizes were found to be the most important factor affecting sediment yield. As the grid‐cell sizes increase, stream meanders are short‐circuited. The shortened stream lengths cause sediment yield to increase by as much as 32%.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Barnwell, T. O., and Johanson, R. (1981). “HSPF: A comprehensive package for simulation of watershed hydrology and water quality.” Proc. of the Seminar on Nonpoint Pollution Control‐Tools and Techniques for the Future, Interstate Committee on the Potomac River Basin, Rockville, Md.
2.
Beasley, D. B., Huggins, L. F., and Monke, E. J. (1980). ANSWERS user's manual. Purdue Univ., West Lafayette, Ind.
3.
Coastal nonpoint pollution control program: Program development and approval guidance. (1991). U.S. Envir. Protection Agency, Washington, D.C., 22–23.
4.
Donigian, A. S., and Crawford, N. (1976). “Nonpoint pollution from the land surface.” EPA 600/3‐76/083, U.S. Envir. Protection Agency, Washington, D.C.
5.
Free, M. H., Onstad, C. A., and Holtan, H. N. (1975). “ACTMO: An agricultural chemical transport model.” Report No. ARS‐H‐3, U.S. Dept. of Agric., Washington, D.C.
6.
Feezor, D. R., Hirschi, M. C., and Lesikar, B. J. (1989). “Effect of cell size on AGNPS prediction.” ASAE Paper No. 89‐2662, American Society of Agric. Engrs. (ASAE), Chicago, Ill.
7.
Goodchild, M. F., and Mark, D. M. (1987). “The fractal nature of geographic phenomena.” Ann. AAG, 77(2), 265–278.
8.
Grayman, W. M. (1975). “Land‐based modeling system for water quality management studies.” J. Hydr. Div., ASCE, 101(5), 567–580.
9.
Grayman, W. M., Males, R. M., and Harris, J. J. (1982). “Use of integrated spatial data and modeling capabilities for urban runoff analyses.” Proc. of the Int. Symp. on Urban Hydrology, Univ. of Kentucky, Lexington, Ky.
10.
Gupta, S. K., and Solomon, S. I. (1977). “Distributed numerical model for estimating runoff and sediment discharge of ungaged rivers. 1: The information system.” Water Resour. Res., 13(3), 613–618.
11.
Hession, C. W., and Shanholtz, V. O. (1988). “A geographic information system for targeting nonpoint source agricultural pollution.” J. Soil Water Conservation, 43(3), 264–266.
12.
Knisel, W. G. (1980). “Creams: A field scale model for chemicals, runoff, and erosion from agricultural management systems (manual).” USDA Conservation Res. Report Number 26, U.S. Dept. of Agric., Washington, D.C.
13.
Needham, S., and Vieux, B. E. (1989). “A GIS for AGNPS parameter input and output mapping.” ASAE Paper No. 89‐2673, American Society of Agric. Engrs. (ASAE), Chicago, Ill.
14.
PC ARC/INFO users guide. (1988). Envir. Systems Res. Inst. (ESRI), Redlands, Calif.
15.
“Variable grid resolution‐issues and requirements.” (1977). Proc. of a Seminar, The Hydrologic Engineering Center, U.S. Army Corps of Engrs., Davis, Calif.
16.
Vieux, B. E. (1991). “Geographic information systems and nonpoint source water quality and quantity modeling.” Int. J. Hydrol. Processes, 5(1), 101–113.
17.
Vieux, B. E. (1993). “DEM aggregation and smoothing effects on direct surface runoff modeling.” J. Comp. Civ. Engrg. (in press).
18.
Vieux, B. E., Herndon, L. P., and Liston, R. (1989). “GIS and water quality modelling for agricultural resource management systems.” ASAE Paper No. 89‐2184, American Society of Agric. Engrs. (ASAE), Chicago, Ill.
19.
Young, R. A. Onstad, C. A., Bosch, D. D., and Anderson, W. P. (1987). AGNPS, agricultural nonpoint source pollution model: A watershed analysis tool. Conservation Res. Report 35, U.S. Dept. of Agric. Agric. Res. Service, Morris, Minn.
20.
Young, C. A., Onstad, C. A., Bosch, D. D., and Anderson, W. P. (1989). “AGNPS: A nonpoint source pollution model for evaluating agricultural watersheds.” J. Soil Water Conservation, 44(2), 168–173.
Information & Authors
Information
Published In
Journal of Water Resources Planning and Management
Volume 119 • Issue 2 • March 1993
Pages: 141 - 157
Copyright
Copyright © 1993 American Society of Civil Engineers.
History
Received: Jan 29, 1992
Published online: Mar 1, 1993
Published in print: Mar 1993
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.