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Analysis of building deformation in landslide area using multisensor PSInSAR ™ technique

View Article: PubMed Central - PubMed

ABSTRACT

We analyze ground deformation velocities of the buildings in San Fratello (Sicily, Italy).

We analyze satellite PSI data using different sensors, acquired from 1992 to 2012.

We performed a damages assessment map after the landslide occurred on the 14th February 2010.

The obtained data were compared to evaluate the residual risk.

The obtained data were compared to evaluate the residual risk.

No MeSH data available.


Building deformation velocity map using both ascending and descending COSMO-SkyMed datasets. The black lines correspond to the secondary scarps developed during the 2010 landslide.
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fig0045: Building deformation velocity map using both ascending and descending COSMO-SkyMed datasets. The black lines correspond to the secondary scarps developed during the 2010 landslide.

Mentions: CSK images were acquired after the 2010 landslide, thus they can be useful to evaluate possible post-event ground deformation phenomena. The available data were acquired only in descending orbit, making them suitable especially to study the deformation of the western slope. Anyway, the high density of the PS allowed to retrieve also interesting information about the eastern slope deformation. The stability range for CSK data was increased to ±2 mm/y because of the higher average standard deviation of PS velocity, if compared to those of the C-band data. The increase of the standard deviation is related to the short acquisition period (only one year) and to the location of San Fratello, which turns out to be far from the reference point and at the boundary of the used SAR images. In this case, the building deformation velocity map permits to recognize three different areas (Fig. 9), along the 2010 landslide crown, where several buildings are affected by a considerable deformation. These areas correspond, from north to south, to the Stazzone, Riana and San Benedetto quarters, which were intensely damaged during the event. The difference in colors between the Stazzone and San Benedetto quarters, that represent different displacement direction, is related to the different position of the areas within the 2010 landslide. Buildings that are moving toward the satellite characterize Stazzone quarter, whereas in San Benedetto the edifices are moving away with respect to the sensor. The first ones are located inside the landslide body, whereas the second ones are placed along the landslide crown. The fractures patterns developed on the building facades suggest that Stazzone is moving downhill, on the contrary part of the building located within the San Benedetto is characterized by mainly vertical movement. This is consistent with the geometry of the landslide, which is rotational in the upper part and translational downward. Another interesting result is represented by the presence of a strip, located along the crown of the 1922 landslide, characterized by several buildings showing high deformation velocities. These edifices present well developed fractures on their facades, confirming that this area is interested by slow but continuous ground deformation. The comparison between the building deformation velocity map, obtained using CSK data, and the damage assessment map shows a very good agreement, confirming that the most intensely damaged area during the 2010 landslide are, today, characterized by residual movements, which compromise their stability. Several of these buildings were recently evacuated and some of them completely demolished. The measurement of the velocities related to residual movements must be used with caution because of the high standard deviation.


Analysis of building deformation in landslide area using multisensor PSInSAR ™ technique
Building deformation velocity map using both ascending and descending COSMO-SkyMed datasets. The black lines correspond to the secondary scarps developed during the 2010 landslide.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5384476&req=5

fig0045: Building deformation velocity map using both ascending and descending COSMO-SkyMed datasets. The black lines correspond to the secondary scarps developed during the 2010 landslide.
Mentions: CSK images were acquired after the 2010 landslide, thus they can be useful to evaluate possible post-event ground deformation phenomena. The available data were acquired only in descending orbit, making them suitable especially to study the deformation of the western slope. Anyway, the high density of the PS allowed to retrieve also interesting information about the eastern slope deformation. The stability range for CSK data was increased to ±2 mm/y because of the higher average standard deviation of PS velocity, if compared to those of the C-band data. The increase of the standard deviation is related to the short acquisition period (only one year) and to the location of San Fratello, which turns out to be far from the reference point and at the boundary of the used SAR images. In this case, the building deformation velocity map permits to recognize three different areas (Fig. 9), along the 2010 landslide crown, where several buildings are affected by a considerable deformation. These areas correspond, from north to south, to the Stazzone, Riana and San Benedetto quarters, which were intensely damaged during the event. The difference in colors between the Stazzone and San Benedetto quarters, that represent different displacement direction, is related to the different position of the areas within the 2010 landslide. Buildings that are moving toward the satellite characterize Stazzone quarter, whereas in San Benedetto the edifices are moving away with respect to the sensor. The first ones are located inside the landslide body, whereas the second ones are placed along the landslide crown. The fractures patterns developed on the building facades suggest that Stazzone is moving downhill, on the contrary part of the building located within the San Benedetto is characterized by mainly vertical movement. This is consistent with the geometry of the landslide, which is rotational in the upper part and translational downward. Another interesting result is represented by the presence of a strip, located along the crown of the 1922 landslide, characterized by several buildings showing high deformation velocities. These edifices present well developed fractures on their facades, confirming that this area is interested by slow but continuous ground deformation. The comparison between the building deformation velocity map, obtained using CSK data, and the damage assessment map shows a very good agreement, confirming that the most intensely damaged area during the 2010 landslide are, today, characterized by residual movements, which compromise their stability. Several of these buildings were recently evacuated and some of them completely demolished. The measurement of the velocities related to residual movements must be used with caution because of the high standard deviation.

View Article: PubMed Central - PubMed

ABSTRACT

We analyze ground deformation velocities of the buildings in San Fratello (Sicily, Italy).

We analyze satellite PSI data using different sensors, acquired from 1992 to 2012.

We performed a damages assessment map after the landslide occurred on the 14th February 2010.

The obtained data were compared to evaluate the residual risk.

The obtained data were compared to evaluate the residual risk.

No MeSH data available.