journal article Open Access Feb 25, 2026

The Importance of Spatial Variability in Estimating Evapotranspiration From a Subalpine Wetland

View at Publisher Save 10.1002/hyp.70451
Abstract
ABSTRACT
The Canadian Rocky Mountains are a critical component to the hydrology, feeding water to many rivers. However, little is still known about the magnitude of hydrological processes (i.e., evapotranspiration (ET), discharge etc.) that comprise the alpine and subalpine hydrologic cycle. Sub‐alpine wetlands have received recent attention for their potential role as water retainers and sources for downstream systems. This purpose of this study was to quantify the ecohydrological controls on ET in a sub‐alpine wetland, using closed chamber measurements. Spatial patterns in evapotranspiration were modelled using the METRIC approach with data collected via a remote aerial vehicle (RAV). Closed chamber measurements for ET were taken in August, 2021, and the results indicated that vapour pressure deficit and net radiation were the significant controls on ET, while no significant influence was seen in vegetation type. The influence of the headwall was also clear as there were significant differences in ET between sunny (avg rate 0.14 ± 0.1 mm/h) and shady (avg rate 0.06 ± 0.4 mm/h) conditions. METRIC ET demonstrated considerable spatial variability, with higher rates located in the western portion of the field site, highlighting the complexity of quantifying ET in subalpine wetlands. When validated against the closed chamber data, METRIC ET captured the general range of ET measurements reasonably well, and had a modelled root mean square error (RMSE) of 0.07 mm/h. However, we recommend that future research test METRIC performance under different seasonal conditions to better quantify the model's capabilities.
Topics

No keywords indexed for this article. Browse by subject →

References
66
[5]
Local Indicators of Spatial Association—LISA

Luc Anselin

Geographical Analysis 10.1111/j.1538-4632.1995.tb00338.x
[16]
Christensen C. W.2017.“A Geophysical Study of Alpine Groundwater Processes and Their Geologic Controls in the Southeastern Canadian Rocky Mountains (Master's Thesis Graduate Studies).”
[20]
ESRI (2021)
[30]
IPCC (2023)
[36]
Narrowband to broadband conversions of land surface albedo I

Shunlin Liang

Remote Sensing of Environment 10.1016/s0034-4257(00)00205-4
[44]
Pallardy S. G.2008. “Photosynthesis.” InPhysiology of Woody Plants 3rd ed. 107–167.Elsevier.https://doi.org/10.1016/B978‐012088765‐1.50006‐3. (Original work published Academic Press). 10.1016/b978-012088765-1.50006-3
[45]
The reflectance at the 950–970 nm region as an indicator of plant water status

J. PEÑUELAS, I. Filella, C. BIEL et al.

International Journal of Remote Sensing 10.1080/01431169308954010
[47]
Pierson F. B. P. R.Robichaud K. E.Spaeth andC. A.Moffet.2001.“Impacts of Fire on Hydrology and Erosion in Steep Mountain Big Sagebrush Communities.”USGS.https://www.tucson.ars.ag.gov/icrw/Proceedings/Pierson.pdf.
[48]
Pomeroy J. W. P.Harder andG.Galloway. (2020. unpublished).UAV Imagery at Bonsai 2020. Unpublished Data.
[49]
Pomeroy J. W. P.Harder andR.Heavens.2020.“Spectral Signatures at Bonsai 2020.”Unpublished Data.
[50]
R Core Team (2024)

Showing 50 of 66 references

Metrics
0
Citations
66
References
Details
Published
Feb 25, 2026
Vol/Issue
40(3)
License
View
Funding
Science and Engineering Research Council
Natural Sciences and Engineering Research Council of Canada
Cite This Article
Sheryl H. M. Chau, Brandon Van Huizen, Richard M. Petrone (2026). The Importance of Spatial Variability in Estimating Evapotranspiration From a Subalpine Wetland. Hydrological Processes, 40(3). https://doi.org/10.1002/hyp.70451