DISCRIMINATING FLUCTUATION DYNAMICS IN BURNED AND UNBURNED VEGETATIONAL COVERS

2005 ◽  
Vol 05 (04) ◽  
pp. L479-L487
Author(s):  
LUCIANO TELESCA ◽  
ROSA LASAPONARA ◽  
ANTONIO LANORTE
Keyword(s):  
Vegetation Dynamics ◽  
Vegetation Index ◽  
Southern Italy ◽  
Temporal Evolution ◽  
Fluctuation Analysis ◽  
Nonstationary Signal ◽  
Fluctuation Dynamics ◽  
Land Covers ◽  
Detrended Fluctuation ◽  
Vegetational Dynamics

Fluctuation dynamics of time series of satellite SPOT-VEGETATION Normalized Difference of Vegetation Index (NDVI) data from 1998 to 2003 were analyzed to discriminate fire-induced variability in the vegetational dynamics of shrub-land in southern Italy. We used detrended fluctuation analysis (DFA), which permits the detection of persistent properties in nonstationary signal fluctuations. We analyzed two shrub-land covers, one in "healthy conditions" (fire-unaffected) and the other in "ill conditions" (fire-affected). Our findings suggest that fires play an important role in the temporal evolution of the shrub-land, increasing the persistence of the vegetation dynamics.

ANALYSIS OF CORRELATION PROPERTIES IN GEOELECTRICAL DATA

Fractals ◽  
2003 ◽  
Vol 11 (01) ◽  
pp. 27-38 ◽  
Author(s):  
GERARDO COLANGELO ◽  
VINCENZO LAPENNA ◽  
LUCIANO TELESCA
Keyword(s):  
Time Series ◽  
Detrended Fluctuation Analysis ◽  
Southern Italy ◽  
Fluctuation Analysis ◽  
Scaling Exponents ◽  
Long Range Correlations ◽  
The Mean ◽  
Correlation Properties ◽  
Seismic Area ◽  
Detrended Fluctuation

This paper considers four geoelectrical time series, measured in a seismic area of Southern Italy. Lomb Periodogram method, Higuchi analysis, Detrended Fluctuation Analysis (DFA) and the mean distance spanned within time L are used to discuss the correlation properties of these signals. The values of the scaling exponents from these methods of the geoelectrical data indicate that the long-range correlations are present. Furthermore, it is found that these correlations are all linear.

FLUCTUATION ANALYSIS OF THE HOURLY TIME VARIABILITY IN OBSERVATIONAL GEOELECTRICAL SIGNALS

2002 ◽  
Vol 02 (03) ◽  
pp. L235-L242 ◽  
Author(s):  
LUCIANO TELESCA ◽  
VINCENZO LAPENNA ◽  
MARIA MACCHIATO
Keyword(s):  
Significant Variation ◽  
Detrended Fluctuation Analysis ◽  
Southern Italy ◽  
Time Variability ◽  
Fluctuation Analysis ◽  
Long Range Correlations ◽  
Power Law Exponent ◽  
Seismic Area ◽  
Detrended Fluctuation ◽  
Geoelectrical Signals

We investigate, by the Detrended Fluctuation Analysis (DFA), the long-range correlations in the hourly time variability of geoelectrical signals measured by the station Tramutola, located in one of the most seismic area of southern Italy. The DFA power-law exponent, characterizing the temporal fluctuations of these signals, shows significant variation, possibly related with the seismic activity of the area investigated.

scholarly journals Multifractality in local geomagnetic field at Etna volcano, Sicily (southern Italy)

2005 ◽  
Vol 5 (4) ◽  
pp. 555-559 ◽  
Author(s):  
G. Currenti ◽  
C. del Negro ◽  
V. Lapenna ◽  
L. Telesca
Keyword(s):  
Geomagnetic Field ◽  
Southern Italy ◽  
Complex Dynamics ◽  
Fluctuation Analysis ◽  
Etna Volcano ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Nonstationary Signals ◽  
Eruptive Event ◽  
Mt Etna ◽  
Detrended Fluctuation

Abstract. We applied the Multifractal Detrended Fluctuation Analysis (MF-DFA), which allows to detect multifractality in nonstationary signals, to the hourly means of local geomagnetic field recorded at Mt. Etna volcano (southern Italy). We studied the signal measured at one geomagnetic station, installed at the summit of volcano, which was characterized by a strong eruption on 27 October 2002. We analyzed two frames of signals, one measured before the eruption and the other after, in order to evaluate dynamical changes induced by the eruptive event. Our findings show that: i) the geomagnetic time series is multifractal; ii) the multifractal degree of the signal decreases after the occurrence of eruption. This study aims to propose another approach to investigate the complex dynamics of volcano-related geomagnetic field.

scholarly journals Analysis of Multifractal and Organization/Order Structure in Suomi-NPP VIIRS Normalized Difference Vegetation Index Series of Wildfire Affected and Unaffected Sites by Using the Multifractal Detrended Fluctuation Analysis and the Fisher–Shannon Analysis

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 415 ◽  
Author(s):  
Rui Ba ◽  
Weiguo Song ◽  
Michele Lovallo ◽  
Siuming Lo ◽  
Luciano Telesca
Keyword(s):  
Time Series ◽  
Detrended Fluctuation Analysis ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Infrared Imaging ◽  
Temporal Dynamics ◽  
Order Structure ◽  
Fluctuation Analysis ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Detrended Fluctuation

The analysis of vegetation dynamics affected by wildfires contributes to the understanding of ecological changes under disturbances. The use of the Normalized Difference Vegetation Index (NDVI) of satellite time series can effectively contribute to this investigation. In this paper, we employed the methods of multifractal detrended fluctuation analysis (MFDFA) and Fisher–Shannon (FS) analysis to investigate the NDVI series acquired from the Visible Infrared Imaging Radiometer Suite (VIIRS) of the Suomi National Polar-Orbiting Partnership (Suomi-NPP). Four study sites that were covered by two different types of vegetation were analyzed, among them two sites were affected by a wildfire (the Camp Fire, 2018). Our findings reveal that the wildfire increases the heterogeneity of the NDVI time series along with their organization structure. Furthermore, the fire-affected and fire-unaffected pixels are quite well separated through the range of the generalized Hurst exponents and the FS information plane. The analysis could provide deeper insights on the temporal dynamics of vegetation that are induced by wildfire.

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