Assessment of Hydrological Behaviour of a Snowmelt-Dominated Catchment at Different Scales

English Abstract:

Snow-dominated catchments are subject to different water input dynamics than their rainfall-dominated counterparts. Therefore, such catchments might experience different runoff generating processes, which might not be appropriately reproduced by the existing conceptual rainfall-runoff models. As a result, understanding about the dominant physical controls on the response of snowmelt-dominated watersheds is crucially important in the selection of hydrologic models. The focus of this research is on the Grand River watershed (7000 km²), the largest watershed in southern Ontario in Canada, which comprises 25 per cent of the Canadian land area draining into Lake Erie. To gain insight into the hydrological functioning of the Grand River watershed – at different spatial scales – data obtained during snowmelt season are used. The data are obtained from numerous sampling experiments in different sub-basins and at multiple points along the main river. The variations in hydrographs over time and scale are analyzed to investigate how they are combined to yield the observed hydrological response of the entire watershed. Subsequently, a structurally flexible hydrologic model (called RAVEN) is designed to reproduce the watershed hydrological response. The model will also be used to address nested hydrologic responses (at different scales).