What are the Limitations of WARP?
The WARP model for atrazine has several limitations and constraints that are important to understand when applying the model and its results: • The sampling frequencies of the model-development sites were not sufficient to reliably characterize the highest concentrations during a year. Thus, application of the models to predict the annual maximum concentration is expected to underpredict the actual annual maximums. • The WARP regression models were derived for estimation of atrazine concentrations in rivers and streams of the conterminous United States. While the 112 stations used for model development represent a wide variety of environmental settings and a large range of watershed area, some watersheds in the United States have one or more characteristics outside the ranges of the watershed characteristics used to develop the models. Application of the models to streams draining such watersheds would result in increased uncertainty in predicted concentrations. • The models were devel
