Principles of Hydrology: A Classroom in the Mountains

Diagnosis of future changes in hydrology for a Canadian Rockies headwater basin
Xing Fang and John W. Pomeroy

Hydrology and Earth System Sciences
Published May 28, 2020

Abstract 
Climate change is anticipated to impact the hydrology of the Saskatchewan River, which originates in the Canadian Rockies mountain range. To better understand the climate change impacts in the mountain headwaters of this basin, a physically based hydrological model was developed for this basin using the Cold Regions Hydrological Modelling platform (CRHM) for Marmot Creek Research Basin (∼9.4 km2), located in the Front Ranges of the Canadian Rockies. Marmot Creek is composed of ecozones ranging from montane forests to alpine tundra and alpine exposed rock and includes both large and small clearcuts. The model included blowing and intercepted snow redistribution, sublimation, energy-balance snowmelt, slope and canopy effects on melt, Penman–Monteith evapotranspiration, infiltration to frozen and unfrozen soils, hillslope hydrology, streamflow routing, and groundwater components and was parameterised without calibration from streamflow. Near-surface outputs from the 4 km Weather Research and Forecasting (WRF) model were bias-corrected using the quantile delta mapping method with respect to meteorological data from five stations located from low-elevation montane forests to alpine ridgetops and running over October 2005–September 2013. The bias-corrected WRF outputs during a current period (2005–2013) and a future pseudo global warming period (PGW, 2091–2099) were used to drive model simulations to assess changes in Marmot Creek’s hydrology. Under a “business-as-usual” forcing scenario, Representative Concentration Pathway 8.5 (RCP8.5) in PGW, the basin will warm up by 4.7 ∘C and receive 16 % more precipitation, which will lead to a 40 mm decline in seasonal peak snowpack, 84 mm decrease in snowmelt volume, 0.2 mm d−1 slower melt rate, and 49 d shorter snow-cover duration. The alpine snow season will be shortened by almost 1.5 months, but at some lower elevations there will be large decreases in peak snowpack (∼45 %) in addition to a shorter snow season. Declines in the peak snowpack will be much greater in clearcuts than under mature forest canopies. In alpine and treeline ecozones, blowing snow transport and sublimation will be suppressed by higher-threshold wind speeds for transport, in forest ecozones, sublimation losses from intercepted snow will decrease due to faster unloading and drip, and throughout the basin, evapotranspiration will increase due to a longer snow-free season and more rainfall. Runoff will begin earlier in all ecozones, but, as a result of variability in surface and subsurface hydrology, forested and alpine ecozones will generate the greatest runoff volumetric increases, ranging from 12 % to 25 %, whereas the treeline ecozone will have a small (2 %) decrease in runoff volume due to decreased melt volumes from smaller snowdrifts. The shift in timing in streamflow will be notable, with 236 % higher flows in spring months and 12 % lower flows in summer and 13 % higher flows in early fall. Overall, Marmot Creek’s annual streamflow discharge will increase by 18 % with PGW, without a change in its streamflow generation efficiency, despite its basin shifting from primarily snowmelt runoff towards rainfall-dominated runoff generation.

For the full article, go here.

DOI: https://doi.org/10.5194/hess-24-2731-2020

Robert Patrick has released a new ebook with Kendall Hunt Publishing: Protecting Sources of Drinking Water: A Guidebook for Indigenous Communities, Watershed Associations, Local Governments and Non-Governmental Organizations.

The ebook can be updated annually, and is practical as a resource book in both academic and non-academic settings. You can order the form or request a review copy at the following website:

https://he.kendallhunt.com/product/protecting-sources-drinking-water-guide-indigenous-communities-watershed-associations-local

Hydrometeorological data from Marmot Creek Research Basin, Canadian Rockies

Xing Fang, John W. Pomeroy, Chris M. DeBeer, Phillip Harder, and Evan Siemens

Earth Syst. Sci. Data, 11, 455-471, 2019
https://doi.org/10.5194/essd-11-455-2019

Implications of stubble management on snow hydrology and meltwater partitioning

Phillip Harder, John W. Pomeroy & Warren D. Helgason

Canadian Water Resources Journal / Revue canadienne des ressources hydriques,

DOI: 10.1080/07011784.2019.1575774

Impact of Future Climate and Vegetation on the Hydrology of an Arctic Headwater Basin at the Tundra–Taiga Transition

Sebastian A. Krogh and John W. Pomeroy

Journal of Hydrometeorology,20(2), 197-215.

doi:10.1175/jhm-d-18-0187.1

Preferential meltwater flowpaths as a driver of preferential elution of chemicals from melting snowpacks 

Diogo Costa, John W. Pomeroy

Science of The Total Environment, 662, 110-120.

doi.org/10.1016/j.scitotenv.2019.01.091 

A long-term hydrometeorological dataset of a northern mountain basin

Kabir Rasouli, John W. Pomeroy, J. Richard Janowicz, Tyler J. Williams,and Sean K. Carey

Earth Syst. Sci. Data, 11, 89-100, 2019
https://doi.org/10.5194/essd-11-89-2019

Centre for Hydrology Senior Research Fellow Paul Whitfield has published a paper in Water Resources Research that shows precipitation is the dominant control on total annual streamflow and on the duration and severity of low flows in mountain rivers. However, mountain low flows are up to 2 times more sensitive than annual streamflow to temperature fluctuations and are very sensitive to winter temperatures above 0 °C as these conditions result in low snowpacks. Climate warming in these mountain catchments may cause more intense and longer low flow periods. 

Challenges in Modeling Turbulent Heat Fluxes to Snowpacks in Forest Clearings

Jonathan P. Conway, John W. Pomeroy, Warren D. Helgason & Nicholas J. Kinar

Journal of Hydrometeorology, 19(10), 1599-1616.

https://doi.org/10.1175/JHM-D-18-0050.1