 |
| Titel |
Shallow soil moisture – ground thaw interactions and controls – Part 2: Influences of water and energy fluxes |
| VerfasserIn |
X. J. Guan, C. Spence, C. J. Westbrook |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 14, no. 7 ; Nr. 14, no. 7 (2010-07-29), S.1387-1400 |
| Datensatznummer |
250012378
|
| Publikation (Nr.) |
 copernicus.org/hess-14-1387-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| The companion paper (Guan et al., 2010) demonstrated variable interactions
and correlations between shallow soil moisture and ground thaw in soil filled
areas along a wetness spectrum in a subarctic Canadian Precambrian Shield
landscape. From wetter to drier, these included a wetland, peatland and soil
filled valley. Herein, water and energy fluxes were examined for these same
subarctic study sites to discern the key controlling processes on the found
patterns. Results showed the presence of surface water was the key control in
variable soil moisture and frost table interactions among sites. At the
peatland and wetland sites, accumulated water in depressions and flow paths
maintained soil moisture for a longer duration than at the hummock tops.
These wet areas were often locations of deepest thaw depth due to the
transfer of latent heat accompanying lateral surface runoff. Although the
peatland and wetland sites had large inundation extent, modified Péclet
numbers indicated the relative influence of external and internal
hydrological and energy processes at each site were different. Continuous
inflow from an upstream lake into the wetland site caused advective and
conductive thermal energies to be of equal importance to ground thaw. The
absence of continuous surface flow at the peatland and valley sites led to
dominance of conductive thermal energy over advective energy for ground thaw.
The results suggest that the modified Péclet number could be a very
useful parameter to differentiate landscape components in modeling frost
table heterogeneity. The calculated water and energy fluxes, and the modified
Péclet number provide quantitative explanations for the shallow soil
moisture-ground thaw patterns by linking them with hydrological processes and
hillslope storage capacity. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|