DRAINMOD-GIS: A lumped parameter watershed scale drainage and water quality model

• Published in: Agricultural water management Vol. 81; no. 1; pp. 77 - 97
• Main Authors: Fernandez, G.P., Chescheir, G.M., Skaggs, R.W., Amatya, D.M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 10.03.2006; Elsevier Science; Elsevier
• Series: Agricultural Water Management
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agronomy. Soil science and plant productions; Biological and medical sciences; Drainage; drainage water; DRAINMOD; Earth sciences; Earth, ocean, space; equations; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; geographic information systems; hydrologic models; Hydrology. Hydrogeology; Irrigation. Drainage; mathematical models; nitrate nitrogen; pollution load; simulation models; Soil and water pollution; soil hydraulic properties; Soil science; soil types; water balance; water flow; Water quality; Water resources; Watershed model; North Carolina; United States; ANW, USA, North Carolina; USA, North Carolina; Drainage; DRAINMOD; Watershed model; Water quality; Uncertainty; Water management; Nitrogen compounds; geographic information systems; Spatial scale; hydrogeology; nitrates; Parameterization; North America; Modeling; Environmental engineering; drainage basins; Water engineering; Simulation model; Hydraulic model; Spatialization; hydrology; streams; Prediction; pollutants; surface water; Kernel function; coastal plains; Inorganic anion; Inorganic nitrogen; water quality; water resource management; Lumped parameter system; Water pollution; drainage; Pollutant load; River water; Drainage water
• ISSN: 0378-3774; 1873-2283
• DOI: 10.1016/j.agwat.2005.03.004

A watershed scale lumped parameter hydrology and water quality model that includes an uncertainty analysis component was developed and tested on a lower coastal plain watershed in North Carolina. Uncertainty analysis was used to determine the impacts of uncertainty in field and network parameters of the model on the predicted outflows and nitrate–nitrogen loads at the outlet of the watershed. The model, which links DRAINMOD field hydrology and a spatially distributed routing model using a kernel function, accurately predicted the outlet flows and nitrate–nitrogen loads from a lower coastal plain watershed. Model predictions were within 1% of both measured outflows and nitrate–nitrogen loads. Uncertainty analysis indicated that uncertainty in stream velocities, decay coefficient and field exports significantly contributed to the uncertainty in the predicted outlet flows, loads and mean watershed delivery ratio.