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| Titel |
Influences of Leaf Area Index estimations on water balance modeling in a Mediterranean semi-arid basin |
| VerfasserIn |
V. Gigante, V. Iacobellis, S. Manfreda, P. Milella, I. Portoghese |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 9, no. 3 ; Nr. 9, no. 3 (2009-06-25), S.979-991 |
| Datensatznummer |
250006804
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| Publikation (Nr.) |
 copernicus.org/nhess-9-979-2009.pdf |
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| Zusammenfassung |
In the present work, the role played by vegetation parameters, necessary to
the hydrological distributed modeling, is investigated focusing on the
correct use of remote sensing products for the evaluation of hydrological
losses in the soil water balance. The research was carried out over a
medium-sized river basin in Southern Italy, where the vegetation status is
characterised through a data-set of multi-temporal NDVI images. The model
adopted uses one layer of vegetation whose status is defined by the Leaf Area
Index (LAI), which is often obtained from NDVI images. The inherent problem
is that the vegetation heterogeneity – including soil disturbances – has a
large influence on the spectral bands and so the relation between LAI and
NDVI is not unambiguous.
We present a rationale for the basin scale calibration of a non-linear
NDVI-LAI regression, based on the comparison between NDVI values and
literature LAI estimations of the vegetation cover in recognized landscape
elements of the study catchment. Adopting a process-based model (DREAM) with
a distributed parameterisation, the influence of different NDVI-LAI
regression models on main features of water balance predictions is
investigated. The results show a significant sensitivity of the hydrological
losses and soil water regime to the alternative LAI estimations. These
crucially affects the model performances especially in low-flows simulation
and in the identification of the intermittent regime. |
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