International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B4. Istanbul 2004
In figure 2 it is presented a screenshot of a GIS application on
Catania Province territory (Italy) about seismic risk. In
GPS technology is useful also for soil movements monitoring,
indeed, it has been successfully applied on a landslide (in
Internatic
many inf
The mon
particular, it is applied an attenuation law (Sabetta, 1987) for Regalbuto town, in Catania Province) where 2-3 cm disposing
the PGA (Peak Ground Acceleration) estimation, using GRID displacements have been weekly recorded. GPS accuracy is possibilit
layers regarding: geology, distance from the supposed
epicentre, seismic wave transmission model of different types
comparable to traditional approach, but many advantages have
been noticed: shorter surveying time and the immediate
time. Thé
the event
of soil, etc. Once obtained a PGA spatial distribution by the disposal of terns of coordinates. By these it is possible to images).
GRID map calculation function, vector layers about built areas, evaluate roto-translation movements of the studied structure (in eruptions
road network and structural and functional point of interest the case, a retaining wall) using plane equations passing dispose t
(such as bridges and viaducts, airport, barracks, etc..) have been through three not aligned point pertaining to the structure. infrastruc
overlaid. In particular, bridges theme has been realized by GIS application could be useful also for prevention planning The mar
quick-static GPS survey on site. The bridges theme's database, about hydro-geologic risk. Starting from geologic and lithologic especially
moreover, contains several useful data for structural cartography it is possible to estimate the most important Etna and
vulnerability evaluation (such as geometric dimensions, mechanical parameter for soils, such as internal friction angle. In oppos
building materials, design criteria, state of conservation, etc.) Applying GRID function to DTM it is easy to derive a slope examined
and hyper-linked photographic documentation. map and, then, to apply a model to evaluate the slopes’ static scenarios
security factor. By the application of specific geotechnic managem
3.2 Hydro-geologic risk models (Ambraseys, 1988; Newmark, 1965) on these data and of a haza
on a PGA distribution map (such as the one in fig.2) it is This diffe
Hydro-geologic studies generally foresee three scenarios: possible to evaluate the slopes’ seismic security factor and, s Vol
l. Hydro-geologic meltdown: The analysis is based on esentually, ta ealeulate the displacements. Soc
specific local features (lithology, cultivation, etc.) and on Another useful prevention ativity 5 icons ‚and ihe + Ema
propensity to landslide of the soils of the studied areas; geometric Survey of existing landstides inorder torcalize a GIS so th
2. Flood: this hazard scenario gives, downflow condition. in vector theme for useful overlaying with road network or built in tit
the section of major interest in relation to the potential risk areas. For these
condition due to specific features of sites and to volume of 33 Volednickisk evaluatio
water predictable for different period of return; Y* ocantess aim that (
3. Overflów: this scenario gives the perimeter of the ar€à$ — Concerning the volcanic risk, scenarios, elaborated by experts, id
potentially interested by exceptional wave, due to the give the perimeters of the areas characterized by different nr tc
breakdown or collapse of an embankments, or exceptional hazard level due to lavic intrusion. The most interesting eu A
flood.
Besides, the areas with an high hazard can be individuated even
national cases are the territory of Etna, the area of Vesuvio and
the Eolian archipelago.
network a
of volcan
thanks to thermic and pluviometric data and to the census of Recent Etna activities (2002-03) have put in evidence another, Pies
crumbling movements. : : not considered yet, hazard factor, in addition to the lavic one: allowina
The application ofgtechmiques of satellite remote Sensing [07 gas and ashes emission that, if protracted for a long time, may hit b Th
dirget acrial Phntogranmen dod of laser Sera fives, n causes heavy condition for human health and for road system rr
case of event, allows the survey of the accident without any gy tionality (with serious consequences for trading and Havine
teams on the site for surveying the support points. Thanks to production activities). 9 m ê
that it is possible to supply the emergency teams, in very short s Bossi IE
time, all the geographic, territorial and environmental determing
information that are fundamental for the coordination of To this ai
his ai
research and rescue teams to help the involved population and
put the territory into safety conditions.
Towns
zc» Highways
State Roads
Provincial Roads
Built areas
| Siciliy
Er (7 4 Landslides
E Slopes security factor
4 f Very good
Good
Figure 5. Satellite image on central Mediterranean area (July
to the eva
order to d
EN d Medium ; a) s : d
$ 3 f 5 Poor 2002). Etna's gas and ashes emission is evidenced in red false Fi 6
/ A > .
N. > € Very poor colour because of an higher temperature eos
; The survey technique, in this sense, offers.a valid support is the
Figure 4. Particular of specialized GIS on hydro-geologic risk. Mt : ; ; For thi
e peta Yorogen on aerial survey with multispectrum images camera. The 7 =
Contribute
potentiality of infra-red camera allows the direct acquisition of
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