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General Information

Basin Overview

The snow-dominated Fraser River basin (FRB) of British Columbia (BC) is one of the largest and most important watersheds of Western North America (Figure 1). The FRB basin covers around 240,000 km², spans one-fourth of BC, and thus forms the greatest salmon rivers with important environmental, economic, and cultural value (Islam et al., 2017). This watershed drains 11 different biogeoclimatic zones, from dry interior plateaus to wet, snowy mountains in its headwaters of the northern Rockies, the Columbia and Coast Mountains and thus integrates a diverse mosaic of landscapes, weather, and climate (Kang et al., 2014). The Basin has a population of 3 million people, nearly two-thirds of all British Columbians. First Nations communities were the first to recognize its special nature and enjoy its bounty. The evidence of Archeology shows oral traditions that the ancestors of First Nations people have inhibited beside the river since the vast glaciers started receding 10,000 years ago and the Fraser River, as we know it, was born (Fraser Basin Council - About the Fraser Basin, 2021).

Some studies report that climate change has affected the FRB’s hydrologic regime during the 20^th and early 21st centuries, influencing its economic vitality and pristine landscapes (Déry et al., 2012). Mean annual air temperature has warmed by ~ 1.4 °C since 1949 across the FRB while total annual precipitation remained stable despite a significant change in its type from snowfall to rainfall (Kang et al., 2014). Changes in the FRB’s climate have impacted the evolution and duration of its seasonal snowpack, resulting in a 19% decline in the contribution of snow to its hydrological regime (Kang et al., 2016). Simulations project that the FRB is currently transitioning from a nival to a pluvio-nival hybrid system due to warmer winter air temperatures and phase changes in precipitation (Kerkhoven and Gan, 2011; Morrison et al., 2002) and incur a rise of 1.4^◦ C in August water temperatures by 2100 (Ferrari et al., 2007). This raises concerns about the impacts of changing hydrology on the occurrence of flood and drought as well as terrestrial and aquatic species and their habitats (Kang et al., 2016).

Figure 1. Fraser River Basin (FRB) including four major sub-basins Upper Fraser,  Nechako, Thompson, and Lower Fraser

Datasets 

Different sources of dataset are used for the drainage set of the FRB. 

Digital Elevation Model (DEM)

The FRB forms one of the largest and most important basins of North America. The highest peak is located at Mount Robson (3954 m, Figure 2). In this study, the elevation data is provided by MERIT Hydro (Yamazaki et al., 2017) with a resolution of 3 arc-second (~90 m at the equator). The MERIT elevations are adjusted to satisfy the condition 'downstream is not higher than its upstream' while minimizing the required modifications from the original DEM.

   Figure 2. Digital elevation map of the FRB

Land Cover (LC)

The land cover types used is based on the North American Land Change Monitoring System (NALCMS) which is a collaborative initiative between Natural Resources Canada/Canada Centre for Remote Sensing (NRCan/CCRS); the United States Geological Survey (USGS); and three Mexican organizations. The land cover dataset is generated at 30 m spatial resolution using observation from 2010 Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+) Landsat sensors. The FRB (Figure 3) is dominated by 12 land cover classes, including needleleaf (53.94%), broadleaf (3.57%), mixed forest (8.89%), shrubland (8.91%), grassland (8.23%), lichen-moss (0.12%), wetland (0.08%), cropland (1.13%), barren land (7.34%), Urban and build-up (0.91%), water (4.07%), and snow and ice (2.8%).

 Figure 3. Land cover types for the FRB

Hydrological structures 

Outlet locations 

In the Fraser basin among 811 available gauge stations located in BC, 92 active ones with continuous records were selected. The minimum drainage area of 200 km² is also used as a criterion for the selection of stations. Based on the drainage area, gauges are categorized into four classes, including extra-large (area > 100,000 km²), large (  3000 km²< area < 100,000 km²), medium (1000 km²< area < 3000 km²), and small ( area < 1000 km²). 

 XL (extra-large), L (Large), M (Medium), S (Small)

Configuration 

The drainage database of the FRB basin is generated in Green Kenue (GK). Some modifications are applied to modify drainage direction and gauge locations. The recent version of MESH (1.4.1728) has been set-up for the FRB. 

Files 

Modifications

References 

Déry, S.J., Hernández-Henríquez, M.A., Owens, P.N., Parkes, M.W., Petticrew, E.L., 2012. A century of hydrological variability and trends in the Fraser River Basin. Environ. Res. Lett. 7, 024019. https://doi.org/10.1088/1748-9326/7/2/024019

Ferrari, M.R., Miller, J.R., Russell, G.L., 2007. Modeling changes in summer temperature of the Fraser River during the next century. J. Hydrol. 342, 336–346. https://doi.org/10.1016/j.jhydrol.2007.06.002

Fraser Basin Council - About the Fraser Basin, 2021. URL https://www.fraserbasin.bc.ca/about_fraser_basin.html (accessed 1.8.21).

Islam, S. ul, Déry, S.J., Werner, A.T., 2017. Future Climate Change Impacts on Snow and Water Resources of the Fraser River Basin, British Columbia. J. Hydrometeorol. 18, 473–496. https://doi.org/10.1175/jhm-d-16-0012.1

Kang, D.H., Gao, H., Shi, X., Islam, S.U., Déry, S.J., 2016. Impacts of a Rapidly Declining Mountain Snowpack on Streamflow Timing in Canada’s Fraser River Basin. Sci. Rep. 6, 1–8. https://doi.org/10.1038/srep19299

Kang, D.H., Shi, X., Gao, H., Déry, S.J., 2014. On the Changing Contribution of Snow to the Hydrology of the Fraser River Basin, Canada. J. Hydrometeorol. 15, 1344–1365. https://doi.org/10.1175/jhm-d-13-0120.1

Kerkhoven, E., Gan, T.Y., 2011. Differences and sensitivities in potential hydrologic impact of climate change to regional-scale Athabasca and Fraser River basins of the leeward and windward sides of the Canadian Rocky Mountains respectively. Clim. Change 106, 583–607. https://doi.org/10.1007/s10584-010-9958-7

Morrison, J., Quick, M.C., Foreman, M.G.G., 2002. Climate change in the Fraser River watershed: Flow and temperature projections. J. Hydrol. 263, 230–244. https://doi.org/10.1016/S0022-1694(02)00065-3

Yamazaki, D., Ikeshima, D., Tawatari, R., Yamaguchi, T., O’Loughlin, F., Neal, J.C., Sampson, C.C., Kanae, S., Bates, P.D., 2017. A high-accuracy map of global terrain elevations. Geophys. Res. Lett. 44, 5844–5853. https://doi.org/10.1002/2017GL072874

Related Pages

• Page:
  Preparing the drainage database file
• Page:
  MESH_drainage_database.r2c
• Page:
  Documentation