The spatial extent of hydrological and landscape changes across the mountains and prairies of Canada in the Mackenzie and Nelson River basins based on data from a warm-season time window

Abstract. East of the Continental Divide in cold interior Western Canada, Mackenzie and Nelson River basins have some world's most extreme variable climates, warming climate is changing landscape, vegetation, cryosphere, hydrology. Available data consist streamflow records from a large number (395) natural (unmanaged) gauged basins, where flow may be perennial or temporary, collected either year-round during only warm season, for different series years between 1910 2012. An annual warm-season time window observations were available across all stations was used to classify (1) regime (2) seasonal trend patterns. Streamflow trends compared changes satellite Normalized Difference Indices. Clustering using dynamic warping, which overcomes differences timing due latitude elevation, identified 12 types. types exhibit strong connection location; there distinction mountains plains associated with ecozones. resulted six patterns that also follow distinct spatial organization. The include one decreasing streamflow, four increasing without structure. mean, minimum, maximum Indices water snow (NDWI NDSI) similar each other but Index vegetation (NDVI) trends. Regime types, patterns, indices showed spatially coherent separating Canadian Rockies mountain ranges west poorly defined drainage east north. Three specific areas change identified: (i) taiga-covered subarctic, greenness while wetness snowcover decreasing, (ii) forested Boreal Plains, particularly mountainous west, streamflows not changing, (iii) semi-arid sub-humid agricultural Prairies, three an increase index observed. largest occurred eastern Prairies.