Are the effects of vegetation and soil changes as important as climate change impacts on hydrological processes?
<p>Hydrological processes are widely understood to be sensitive to changes in climate, but the effects of concomitant changes in vegetation and soils have seldom been considered in snow-dominated mountain basins. The response of mountain hydrology to vegetation/soil changes in the present and...
Main Authors: | , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2019-12-01
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Series: | Hydrology and Earth System Sciences |
Online Access: | https://www.hydrol-earth-syst-sci.net/23/4933/2019/hess-23-4933-2019.pdf |
Summary: | <p>Hydrological processes are widely understood to be
sensitive to changes in climate, but the effects of concomitant changes in
vegetation and soils have seldom been considered in snow-dominated mountain
basins. The response of mountain hydrology to vegetation/soil changes in the
present and a future climate was modeled in three snowmelt-dominated
mountain basins in the North American Cordillera. The models developed for each basin using the Cold Regions Hydrological Modeling platform employed current and expected changes to
vegetation and soil parameters and were driven with recent and perturbed high-altitude meteorological observations. Monthly perturbations were calculated
using the differences in outputs between the present- and a future-climate
scenario from 11 regional climate models. In the three basins, future
climate change alone decreased the modeled peak snow water equivalent (SWE)
by 11 %–47 % and increased the modeled evapotranspiration by 14 %–20 %.
However, including future changes in vegetation and soil for each basin
changed or reversed these climate change outcomes. In Wolf Creek in the
Yukon Territory, Canada, a statistically insignificant increase in SWE due to
vegetation increase in the alpine zone was found to offset the statistically
significant decrease in SWE due to climate change. In Marmot Creek in the
Canadian Rockies, the increase in annual runoff due to the combined effect
of soil and climate change was statistically significant, whereas their
individual effects were not. In the relatively warmer Reynolds Mountain in
Idaho, USA, vegetation change alone decreased the annual runoff volume by 8 %,
but changes in soil, climate, or both did not affect runoff. At high
elevations in Wolf and Marmot creeks, the model results indicated that
vegetation/soil changes moderated the impact of climate change on peak SWE,
the timing of peak SWE, evapotranspiration, and the annual runoff volume.
However, at medium elevations, these changes intensified the impact of
climate change, further decreasing peak SWE and sublimation. The
hydrological impacts of changes in climate, vegetation, and soil in mountain
environments were similar in magnitude but not consistent in direction for
all biomes; in some combinations, this resulted in enhanced impacts at lower
elevations and latitudes and moderated impacts at higher elevations and
latitudes.</p> |
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ISSN: | 1027-5606 1607-7938 |