RICEWQ Version 1.9
RICEWQ version 1.9 is now available and can be downloaded from the model download page. This version includes a change in the diffusion equation and an expanded documentation on model theory and input parameter selection. We would like to thank Yuzhou Luo, Ph.D. (California Department of Pesticide Regulation) for spotting an error in the calculation for soil-pore water in the water-sediment diffusion equation. The diffusion equation was taken directly from the Simulator for Water Resources in Rural Basins-Water Quality (SWRRBWQ)* and the same issue exists in SWRRBWQ and other water quality models that share similar algorithms. The error has neglible effect on predicted concentrations for scenarios with pesticide applications to flooded paddies, or with calibrated datasets, but it can result in an overestimate on pesticide mass in sediment when simulating pesticide applications to dry paddies. The expanded documentation presents additional background on model algorithms, including the revised diffusion equation, and includes guidelines for selecting seepage, volatilizaiton, diffusion, and other coefficients.
You can also download the RICEWQ Users Manual without downloading the model. Waterborne will provide the source code of RICEWQ upon request. Please use the form on the Contact Us page to email us your request
*Arnold, J.G., J.R Williams, R. H. Griggs, and N.B. Sammons, 1991. SWRRBWQ: a basin scale model for assessing management impacts on water quality: U.S. Department of Agriculture, Agricultural Research Service, Grassland, Soil and Water Research Laboratory, Temple, Texas.
