The goal of this commentary is to critically evaluate the use popular performance metrics in hydrologic modeling. We focus on Nash-Sutcliffe Efficiency (NSE) and Kling-Gupta (KGE) metrics, which are both widely used research practice around world. Our specific objectives are: (a) provide tools that quantify sampling uncertainty metrics; (b) across a large sample catchments; (c) prescribe further is, needed improve estimation, interpretation, large-sample analysis demonstrates there...

Changes in air temperature, precipitation, and, some cases, glacial runoff affect the timing of river flow watersheds western Canada. We present a method to detect streamflow phase shifts pluvial, nival, and rivers. The Kendall‐Theil robust lines yield monotonic trends normalized sequent 5‐day means nine basins Canada over period 1960–2006. In comparison date annual peak center volume, two other less metrics often used infer changes, our approach reveals more detailed structure on nature...

This paper provides an overview of the key processes that generate floods in Canada, and a context for other papers this special issue – provide detailed examinations specific flood-generating processes. The historical flooding Canada is outlined, followed by summary regional aspects descriptions these regions, including generated snowmelt, rain-on-snow rainfall. Some flood are particularly relevant, or which have been less well studied described: groundwater, storm surges, ice-jams urban...

In late June 2013, heavy rainfall and rapidly melting alpine snow triggered flooding throughout much of the southern half Alberta. Heavy commenced on 19 continued for 3 days. When event was over, more than 200 mm as 350 precipitation had fallen over Front Ranges Canadian Rocky Mountains. Tributaries to Bow River including Ghost, Kananaskis, Elbow, Sheep Highwood, many their tributaries, all reached flood levels. The storm a large spatial extent causing north south in Red Deer Oldman Basins,...

Abstract The Pacific Decadal Oscillation (PDO) is a large-scale climate system feature that influences the surface and hydrology of western North America. In this paper, we review literature describing PDO demonstrate its effects on temperature, precipitation, snowfall, glacier mass balance, streamflow with focus Canada, particularly British Columbia. We how index was developed discuss other patterns resemble PDO. impacts balance from retrospective studies are also reviewed illustrated...

Flood events in Canada result larger costs, terms of property damage, than any other natural disaster. Changes land use, and more recently the impacts climate change, can lead to changes flood regime. This paper describes research examining regime for watersheds across Canada. To distinguish between resulting from land-use those occurring due climate, analysis data is conducted only on that are either part a formal Reference Hydrologic Network (RHN), or which exhibit RHN-like...

Abstract In the mountainous regions of western North America, snowmelt recharges groundwater and provides ecosystem‐sustaining base flow during low‐flow periods. Continued warming is expected to have large impacts on hydrology regimes, but relative impact temperature precipitation low flows unclear. To address this knowledge gap, dominant climate controls summer winter season in 63 near‐natural catchments ecoregions America are identified with correlation analysis, sensitivity quantified...

Abstract In western North America (WNA), mountain snowpack supplies much of the water used for irrigation, municipal, and industrial uses. Thus, snow droughts (a lack accumulation in winter) can have drastic ecological socioeconomic impacts. this study, historical (1951–2013) frequency, severity, risk (frequency × severity) dry, warm, warm dry are quantified at grid‐cell ecoregion scale snow‐dominated regions United States southwestern Canada (sWNA). Based on multiple linear regression...

Whether or not the impact of warming on mountain snow and runoff can be offset by precipitation increases has been well examined, but it is crucially important for future downstream water supply. Using physically based Cold Regions Hydrological Modelling Platform (CRHM), elasticity (percent change in divided a climate forcing) sensitivity regimes to perturbations were investigated three well-instrumented research basins spanning northern North American Cordillera. Hourly meteorological...

Climatic and hydrologic variations between the decades 1976–1985 1986–95 are examined at 210 climate stations for temperature, 271 precipitation, 642 hydrology from across Canada. The in distributed a broad spatial area. Temperatures were generally warmer more recent decade, with many showing significant increases during spring fall. Significant decreases temperature found winter eastern frequent western Canada than east. precipitation also prevalent north, as south, except Ontario Quebec...

Abstract Identifying climate-driven trends in river flows on a global basis is hampered by lack of long, quality time series data for rivers with relatively undisturbed regimes. This problem compounded the support essential long-term monitoring. Experience demonstrates that, clear strategic objectives, and sponsoring organizations, reference hydrologic networks can constitute an exceptionally valuable source to effectively identify, quantify interpret hydrological change—the speed magnitude...

Temporary streams lack streamflow at some time in the seasonal cycle, and include ephemeral, intermittent episodic streams. They often serve as headwaters for perennial stream network a drainage basin, given that headwater can comprise majority of network, temporary are significant hydrologic features across country. Nevertheless, they have received relatively little attention compared to In addition, much previous work on has focussed semi-arid arid landscapes where annual...

Abstract We assessed the impacts of some key Pacific ocean‐atmosphere circulation patterns on annual cycles temperature and precipitation across British Columbia, Yukon, southeast Alaska. The El Niño‐Southern Oscillation (ENSO), Decadal (PDO), ENSO conditional PDO states were considered in composite analyses 71 long, high‐quality datasets from surface meteorological stations. Month‐by‐month, station‐by‐station Monte Carlo bootstrap tests employed to assess statistical significance. results...

Abstract Recent flood events in Canada have led to speculation that changes behaviour are occurring; these often been attributed climate change. This paper examines data for a collection of 132 gauging stations Canada. All watersheds part the Canadian Reference Hydrometric Basin Network (RHBN), group specifically assembled assist identification impacts The RHBN considered good quality and were screened avoid influences regulation, diversions, or land use Daily flow each watershed used derive...

Abstract. Station-based serially complete datasets (SCDs) of precipitation and temperature observations are important for hydrometeorological studies. Motivated by the lack station North America, this study seeks to develop an SCD from 1979 2018 data. The new America (SCDNA) includes daily precipitation, minimum (Tmin⁡), maximum (Tmax⁡) data 27 276 stations. Raw meteorological were obtained Global Historical Climate Network Daily (GHCN-D), Surface Summary Day (GSOD), Environment Change...

Abstract. Probabilistic methods are useful to estimate the uncertainty in spatial meteorological fields (e.g., patterns of precipitation and temperature across large domains). In ensemble probabilistic methods, “equally plausible” members used approximate probability distribution, hence uncertainty, a spatially distributed variable conditioned available information. The can be evaluate impact uncertainties for myriad applications. This study develops Ensemble Meteorological Dataset North...

Abstract This study is a selected search of streamflow records in south-central British Columbia for changes that may be associated with climate change. A force analysis approach was used to identify watersheds and segments hydrologic which were most likely responsive changing climate. Initially three an additional added the effects drainage area land use intervention. It found spring runoff starts earlier, late summer – early fall flows are lower, winter higher warmer These statistically...

Abstract The Georgia Basin–Puget Sound Lowland region of British Columbia (Canada) and Washington State (USA) presents a crucial test in environmental management due to its combination abundant salmonid habitat, rapid population growth urbanization, multiple national jurisdictions. It is also hydrologically complex heterogeneous, containing at least three streamflow regimes: pluvial (rainfall‐driven winter freshet), nival (melt‐driven summer hybrid (both freshets), reflecting differing...