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| Titel |
Time series analysis of the long-term hydrologic impacts of afforestation in the Águeda watershed of north-central Portugal |
| VerfasserIn |
D. Hawtree, J. P. Nunes, J. J. Keizer, R. Jacinto, J. Santos, M. E. Rial-Rivas, A.-K. Boulet, F. Tavares-Wahren, K.-H. Feger |
| 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 ; 19, no. 7 ; Nr. 19, no. 7 (2015-07-10), S.3033-3045 |
| Datensatznummer |
250120759
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| Publikation (Nr.) |
 copernicus.org/hess-19-3033-2015.pdf |
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| Zusammenfassung |
| The north-central region of Portugal has undergone significant land cover
change since the early 1900s, with large-scale replacement of natural
vegetation types with plantation forests. This transition consisted of an
initial conversion primarily to Pinus pinaster, followed by a secondary transition to
Eucalyptus globulus. This land cover change is likely to have altered the hydrologic
functioning of this region; however, these potential impacts are not fully
understood. To contribute to a better understanding of the potential
hydrologic impacts of this land cover change, this study examines the
temporal trends in 75 years of data from the Águeda watershed (part of
the Vouga Basin) over the period of 1936–2010. A number of
hydrometeorological variables were analyzed using a combined Thiel–Sen/Mann–Kendall
trend-testing approach, to assess the magnitude and
significance of patterns in the observed data. These trend tests indicated
that there have been no significant reductions in streamflow over either the
entire test period, or during sub-record periods, despite the large-scale
afforestation which has occurred. This lack of change in streamflow is
attributed to the specific characteristics of the watershed and land cover
change. By contrast, a number of significant trends were found for baseflow
index, with positive trends in the early data record (primarily during
Pinus pinaster afforestation), followed by negative trends later in the data record
(primarily during Eucalyptus globulus afforestation). These trends are attributed to land use
and vegetation impacts on streamflow generating processes, both due to
species differences and to alterations in soil properties (i.e., infiltration
capacity, soil water repellency). These results highlight the importance of
considering both vegetation types/dynamics and watershed characteristic when
assessing hydrologic impacts, in particular with respect to soil properties. |
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