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Titel |
Hydrological heterogeneity in Mediterranean reclaimed slopes: runoff and sediment yield at the patch and slope scales along a gradient of overland flow |
VerfasserIn |
L. Merino-Martín, M. Moreno-de las Heras, S. Pérez-Domingo, T. Espigares, J. M. Nicolau |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 16, no. 5 ; Nr. 16, no. 5 (2012-05-08), S.1305-1320 |
Datensatznummer |
250013289
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Publikation (Nr.) |
copernicus.org/hess-16-1305-2012.pdf |
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Zusammenfassung |
Hydrological heterogeneity is recognized as a fundamental ecosystem
attribute in drylands controlling the flux of water and energy through
landscapes. Therefore, mosaics of runoff and sediment source patches and
sinks are frequently identified in these dry environments. There is a
remarkable scarcity of studies about hydrological spatial heterogeneity in
restored slopes, where ecological succession and overland flow are
interacting. We conducted field research to study the hydrological role of
patches and slopes along an "overland flow gradient" (gradient of overland
flow routing through the slopes caused by different amounts of run-on coming
from upslope) in three reclaimed mining slopes of Mediterranean-continental
climate. We found that runoff generation and routing in non-rilled slopes
showed a pattern of source and sink areas of runoff. Such hydrological
microenvironments were associated with seven vegetation patches
(characterized by plant community types and cover). Two types of sink
patches were identified: shrub Genista scorpius patches could be considered as "deep
sinks", while patches where the graminoids Brachypodium retusum and Lolium perenne dominate were classified as
"surface sinks" or "runoff splays". A variety of source patches were
also identified spanning from "extreme sources" (Medicago sativa patches; equivalent to
bare soil) to "poor sources" (areas scattered by dwarf-shrubs of Thymus vulgaris or
herbaceous tussocks of Dactylis glomerata). Finally, we identified the volume of overland flow
routing along the slope as a major controlling factor of "hydrological
diversity" (heterogeneity of hydrological behaviours quantified as Shannon
diversity index): when overland flow increases at the slope scale
hydrological diversity diminishes. |
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