Added Value of Alternative Information in Interpolated Precipitation Datasets for Hydrology

Gridded climate datasets are produced in many parts of the world by applying various interpolation methods to weather observations, to which are sometimes added secondary information (in addition to geographic location) such as topography and radar or atmospheric model outputs. For a region of interest, the choice of a dataset for a given study can be a significant challenge given the lack of information on the similarities and differences that exist between datasets, or about the benefits that one dataset may present relative to another. This study aims to provide information on the spatial and temporal differences between gridded precipitation datasets and their implication for hydrological modeling. Three gridded datasets for the province of Quebec are considered: the Natural Resources Canada (NRCan) dataset, the Canadian Pre- cipitation Analysis (CaPA) dataset, and the dataset from the Ministère du Développement Durable, de l’Environnement et de la Lutte contre les Changements Climatiques du Québec (MDDELCC). Using sta- tistical metrics and diagrams, these precipitation datasets are compared with each other. Hydrological re- sponses of 181 Quebec watersheds with respect to each gridded precipitation dataset are also analyzed using the hydrological model HSAMI. The results indicate strong similarities in the southern parts and disparities in the central and northern parts of the province of Quebec. Analysis of hydrological simulations indicates that the CaPA dataset offers the best results, particularly for watersheds located in the central and northern parts of the province. MDDELCC shows the best performance in watersheds located on the south shore of the St. Lawrence River and comes out as the overall second-best option.