Approccio analitico per la valutazione della pericolosità da frana: l’esempio di un’area di

El Salvador (C.A.)

DATABASE AND ACTVITIES- bibliographic data collection and analysis;- vectorized geological map;- geological and geomorphological field control;- aerial view (helicopter);- vectorized aerial photographs analysis;- vectorized topographic maps;- DTEM (Digital Terrain Elevation Model) extraction;- slope analysis;- GIS (Geographic Information System) data spatial analysis;- hazard zoning criteria definition;- hazard mapping.

- Define causes and typology of landslides- Individuate and map all the landforms indicating instability conditions or that can control slope processes- Define hazard models - Define hazard classes and mapping rules

TASKS

- Geomorphological and Landslide Hazard Maps (scale 1:25.000)- GIS open database setting-up

PRODUCTS

APPLICATIONS

- Civil protection- Land-use planning- Landslide Hazard geotechnical assessment- Landslide Risk Assessment

Santa Tecla2.12.00

Santa Tecla16.01.01

LANDSLIDEANALYSIS

ante (remote) and post (field) landslide events

HAZARDMODELS AND

CLASSES

LANDSLIDECAUSES

REMOTE SENSING(1996 – 1:20.000)

Geomorphological map

DTEM PROCESSING(1980 – 1:25.000 – eq. 10 m)

Slope map

GIS ANALYSIS

HAZARDMAP

DATA

HAZARDGIS DataBase

Hazard class Description

a landslide bodies, alluvial and debris fan

I Very high b areas subtended by landslides and fluvial (b’) scarps

c talus slopes

d highly steep slope areas (>55°)

a areas on the border rim of cliffs and landslide scarps

II High b areas underlying landslide bodies, highly steep slopes, talus slopes, alluvial or debris fans

c steep slope areas (25°÷55°)

III Medium Slightly steep slopes (5°÷25°)

IV Low or Null Planar or sub-planar surfaces (<5°)