Scheda di dettaglio – i prodotti della ricerca
| Dato | Valore |
|---|---|
| Title | INFLUENCES OF LEAF AREA INDEX ESTIMATIONS ON WATER BALANCE MODELING IN A MEDITERRANEAN SEMI-ARID BASIN |
| Abstract | 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 multitemporal 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 redictions 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 lowflows simulation and in the identification of the intermittent regime. |
| Source | Natural hazards and earth system sciences (Print) 9, pp. 979–991 |
| Keywords | VEGETATION INDEXESAVHRR DATASOIL TRANSPIRATION |
| Journal | Natural hazards and earth system sciences (Print) |
| Editor | Copernicus Publ., Göttingen, Germania |
| Year | 2009 |
| Type | Articolo in rivista |
| Authors | GIGANTE V., IACOBELLIS V., MANFREDA S., MILELLA P., PORTOGHESE I. |
| Text | 42347 2009 ISI Web of Science WOS WOS 000267543300030 Scopus ISSN 15618633 VEGETATION INDEXES AVHRR DATA SOIL TRANSPIRATION INFLUENCES OF LEAF AREA INDEX ESTIMATIONS ON WATER BALANCE MODELING IN A MEDITERRANEAN SEMI ARID BASIN GIGANTE V., IACOBELLIS V., MANFREDA S., MILELLA P., PORTOGHESE I. COS OT Consortium, University of Basilicata, Potenza, Italy DIAC Department, Polytechnic University of Bari, Bari, Italy DIFA Department, University of Basilicata, Potenza, Italy PRO.GE.SA. Department, University of Bari, Bari, Italy 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 multitemporal 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 redictions 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 lowflows simulation and in the identification of the intermittent regime. 9 http //www.nat hazards earth syst sci.net/9/979/2009/ published_paper nhess_9_979_2009.pdf Articolo in rivista Copernicus Publ. 1561 8633 Natural hazards and earth system sciences Print Natural hazards and earth system sciences Print Nat. hazards earth syst. sci. Print Natural hazards and earth system sciences. Print NHESS Print Print ivan.portoghese PORTOGHESE IVAN TA.P04.005.007 Strumenti di mitigazione dello stress quali quantitativo per i sistemi idrici |