 |
| Titel |
Soil moisture gradients and controls on a southern Appalachian hillslope from drought through recharge |
| VerfasserIn |
J. A. Yeakley, W. T. Swank, L. W. Swift, G. M. Hornberger, H. H. Shugart |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 2, no. 1 ; Nr. 2, no. 1, S.41-49 |
| Datensatznummer |
250000392
|
| Publikation (Nr.) |
 copernicus.org/hess-2-41-1998.pdf |
|
|
|
|
|
| Zusammenfassung |
| Soil moisture gradients along hillslopes in humid
watersheds, although indicated by vegetation gradients and by studies using models, have
been difficult to confirm empirically. While soil properties and topographic features are
the two general physio-graphic factors controlling soil moisture on hillslopes, studies
have shown conflicting results regarding which factor is more important. The relative
importance of topographic and soil property controls was examined in an upland forested
watershed at the Coweeta Hydrologic Laboratory in the southern Appalachian mountains. Soil
moisture was measured along a hillslope transect with a mesic-to-xeric forest vegetation
gradient over a period spanning precipitation extremes. The hillslope was transect
instrumented with a time domain reflectometry (TDR) network at two depths. Soil moisture
was measured during a severe autumn drought and subsequent winter precipitation recharge.
In the upper soil depth (0-30 cm), moisture gradients persisted throughout the measurement
period, and topography exerted dominant control. For the entire root zone (0-90 cm), soil
moisture gradients were found only during drought. Control on soil moisture was due to
both topography and storage before drought. During and after recharge, variations in soil
texture and horizon distribution exerted dominant control on soil moisture content in the
root zone (0-90 cm). These results indicate that topographic factors assert more control
over hillslope soil moisture during drier periods as drainage progresses, while variations
in soil water storage properties are more important during wetter periods. Hillslope soil
moisture gradients in southern Appalachian watersheds appear to be restricted to upper
soil layers, with deeper hillslope soil moisture gradients occurring only with sufficient
drought. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|