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| Titel |
Vegetation pattern of Istanbul from the Landsat data and the relationship with meteorological parameters |
| VerfasserIn |
Zafer Aslan, Krishnaier Natarajan, Mehmet Tankut |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 12, no. 6 ; Nr. 12, no. 6, S.574-584 |
| Datensatznummer |
250010914
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| Publikation (Nr.) |
 copernicus.org/angeo-12-574-1994.pdf |
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| Zusammenfassung |
| This paper discusses the preliminary results
of a study on the vegetation pattern and its relationship with meteorological
parameters in and around Istanbul. The study covers an area of over 6800 km2
consisting of urban and suburban centers, and uses the visible and near-infrared
bands of Landsat. The spatial variation of the Normalized Difference Vegetation
Index (NDVI) and meteorological parameters such as sensible heat flux, momentum
flux, relative humidity, moist static energy, rainfall rate and temperature have
been investigated based on observations in ten stations in the European
(Thracian) and Anatolian parts of Istanbul. NDVI values have been evaluated from
the Landsat data for a single day, viz. 24 October 1986, using ERDAS in ten
different classes. The simultaneous spatial variations of sensible heat and
momentum fluxes have been computed from the wind and temperature profiles using
the Monin-Obukhov similarity theory. The static energy variations are based on
the surface meteorological observations. There is very good correlation between
NDVI and rainfall rate. Good correlation also exists between: NDVI and relative
humidity; NDVI, sensible heat flux and relative humidity; NDVI, momentum flux
and emissivity; and NDVI, sensible heat flux and emissivity. The study suggests
that the momentum flux has only marginal impact on NDVI. Due to rapid
urbanization,the coastal belt is characterized by reduced NDVI compared to the
interior areas, suggesting that thermodynamic discontinuities considerably
influence the vegetation pattern. This study is useful for the investigation of
small-scale circulation models, especially in urban and suburban areas where
differential heating leads to the formation of heat islands. In the long run,
such studies on a global scale are vital to gain accurate, timely information on
the distribution of vegetation on the earth's surface. This may lead to an
understanding of how changes in land cover affect phenomena as diverse as the
atmospheric CO2 concentrations, the hydrological cycle and the energy
balance at the surface-atmosphere interface. |
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