Predicting the daily streamflow of ungauged catchments in SE Australia by regionalising the parameters of a lumped conceptual rainfall-runoff model

Deriving relationships between catchment-scale hydrologic response and land scape attributes allows the hydrologic response of an ungauged catchment to be predicted from its landscape attributes and climate. In this study, a l umped conceptual rainfall-runoff model was applied at a daily timestep to 1 6 small (less than 1 km(2)) catchments in the Maroondah region of Victoria, Australia. The six parameters of this model can be used to characterise th e daily streamflow of the catchments. It was demonstrated in Post and Jakem an (1996) [Post, D.A., Jakeman, A.J., 1996. Relationships between catchment attributes and hydrological response characteristics in small Australian m ountain ash catchments. Hydrol. Processes 10: 877-892] that these six param eters are related to the landscape attributes of the catchments. In the cur rent paper, these relationships are quantified and used to predict the dail y streamflow of each catchment from its landscape attributes and daily rain fall and temperature, as if it were ungauged for streamflow. This predicted streamflow is then compared with the observed streamflow of the catchment. These relationships may also be used to predict the daily streamflow from other, similarly sized catchments in the Maroondah region. Some of the rela tionships between the model parameters and landscape attributes are well de fined, while others are quite poor. As a result, the predictions of daily s treamflow also vary in quality. Improvement of these results can be obtaine d through better understanding of the controls on hydrologic response. (C) 1999 Elsevier Science B.V. All rights reserved.