Comment on Cao W, Bowden BW, Davie T, Fenemor A. 2006. `Multi-variable and multi-site calibration and validation of SWAT in a large mountainous catchment with high spatial variability'. Hydrological Processes 20(5): 1057-1073

Recently, a manuscript was published with the objective to complete a multivariable and multisite calibration and validation for the Soil and Water Assessment Tool (SWAT) model on the Motueka River basin by Cao et al. (2006). Physically based distributed parameter models, such as SWAT, have become a preferred tool to predict watershed response not only at the watershed outlet, but also at intermediate points within the watershed. Calibrating and validating such models before they can be applied to make watershed decisions is always a challenge. A methodology to perform multisite and multiparameter calibration should be of interest to a wide rage of stakeholders working in the area of watershed management. However, upon reviewing this paper, we felt two topics warranted additional discussion.