A benchmark for probabilistic seasonal streamflow forecasting across North America
Abstract
Seasonal streamflow forecasts represent critical operational inputs for water sectors and society, for instance for spring flood early warning, water supply, hydropower generation, and irrigation scheduling. Initial hydrologic conditions (e.g., snow cover and soil moisture) are an important driver of hydrologic predictions on these timescales. In high-latitude and/or high-altitude basins across N. America (including basins downstream), snow is one of the main sources of runoff generation. As a result, data-driven forecasting from snow observations is a well-established approach for operational streamflow forecasting in the US and Canada. As part of the Canadian Global Water Futures (GWF) program, we are advancing capabilities for probabilistic streamflow forecasting over N. America. The first aim of this work is to benchmark probabilistic seasonal streamflow predictability across the continent. To this end, a data-driven probabilistic seasonal streamflow hindcasting system is being developed and implemented for basins with a nival regime across N. America. It uses snow water equivalent measurements from the recently updated Canadian historical Snow Water Equivalent dataset (CanSWE, 19282020; Vionnet et al., 2021) and from the Natural Resources Conservation Service (NRCS) manual snow course dataset in the US. These datasets are first gap filled using quantile mapping based on neighbouring snow and precipitation stations (SCDNA dataset; Tang et al., 2020). The gap filled datasets are then used as inputs to a regression model, to generate probabilistic hindcasts of streamflow volumes for basins across N. America. Preliminary results indicate that this approach is skilful (i.e., better than streamflow climatology) for basins across the Canadian Rockies. References Tang, G., Clark, M. P., Newman, A. J., Wood, A. W., Papalexiou, S. M., Vionnet, V., and Whitfield, P. H.: SCDNA: a serially complete precipitation and temperature dataset for North America from 1979 to 2018, Earth Syst. Sci. Data, 12, 23812409, https://doi.org/10.5194/essd-12-2381-2020, 2020. Vionnet, V., Mortimer, C., Brady, M., Arnal, L., and Brown, R.: Canadian historical Snow Water Equivalent dataset (CanSWE, 19282020), Earth Syst. Sci. Data Discuss. [preprint], https://doi.org/10.5194/essd-2021-160, in review, 2021.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.H54E..03A