Use of catchment attributes to identify the scale and values of distributed parameters in surface and sub-surface conceptual hydrology models

Abstract

Improved prediction for problems in catchment hydrology requires an ability to spatially disaggregate and connect surface and sub-surface components. This paper considers two hydrological models for use in such disaggregation and coupling: a lumped conceptual rainfall-runoff model (IHACRES) and a physics based conceptual groundwater discharge model. Smaller gauged catchments in the vicinity can be used to regionalise and parameterise the coupled model using catchment attributes prior to running the model in a larger catchment with fewer gauges. Regionalisation in gauged catchments at appropriate scales would capture the uncertainty of the relationships between catchment attributes and model parameter values, including the upper and lower boundary of parameter values. In an ungauged and disaggregated catchment, its landscape attributes would be inserted into the regional relationships to provide the parameter bounds for constraining the proposed coupled model. The aim of this catchment disaggregation is to be able to improve on previous catchment or sub-catchment recharge-discharge models, so that modelling can be carried out at the management scale. Show more