Geology Geomorphology and Landslide

Home , Altilia, Cosenza

Programma Operativo Nazionale “Ricerca e Competitività 2007‐2013” Regioni Convergenza ASSE I ––SostegnoSostegno ai mutamenti strutturali Obiettivo Operativo: Aree scientifico‐tecnologiche generatrici di processi di trasformazione del sistema produttivo e creatrici di nuovi settori Azione: Interventi di sostegno della ricerca industriale

GEOLOGY, GEOMORPHOLOGY AND LANDSLIDE SUCEPTIBILITY ALONG A HIGHWAY SECTION IN NORTHERN CALABRIA (ITALY) Working group: Francesco Muto1, Massimo Conforti2, Salvatore Critelli1, Davide Fabbricatore1, Luciana Filomena1, Teresa Pelle1, Valeria Rago1, Gaetano Robustelli1, Fabio Scarciglia1, Vincenzo Tripodi1 1 DiBEST-Università della Calabria, Arcavacata di Rende (CS), Italy 2 CNR–ISAFOM, Rende (CS), Italy Geological and Hydraulic Safety along Motorways and Railways Università della Calabria, Arcavacata di Rende (CS), 25 –26 November 2014 Aula Magna Cosenza Aims Sud

Research project PON01-01503 “Integrated Systems for Hydrogeological Risk Monitoring, Early Warning and Mitigation Along the Main Lifelines” – Multidisciplinary approach Hydrogeological risk mitigation and early warning along 3 highway sections of southern Italy Assessment of landslide susceptibility along the A3 highway section between Cosenza Sud and Altilia in northern Calabria (~26 km) Altilia Geological and structural setting Carbonate rocks N‐S trending Savuto fault system (Mesozoic)

Metamorphic rocks (Palaeozoic)

Clay Unit (Upper Miocene) North Palaeozoic metamorphic and N‐S fault plutonic basement rocks Mesozoic to Paleogene ophiolitic, metasedimentary and sedimentary rocks Miocene to Quaternary Tansi et al. (2007) sedimentary cover Geomorphological features Geological, lithological and structural control; Weathering and morphodynamic processes

Fault scarps, high local relief and stream incision, lateral and vertical juxtaposition of terrains with different behaviour in respect to erosion and mass movements COSENZA sud COSENZA sud

Geological Lithological map map

ALTILIA ‐ GRIMALDI ALTILIA ‐ GRIMALDI Geomorphological map COSENZA sud

ALTILIA ‐ GRIMALDI Landslide inventory maps Legend

Landslide scarp Active Dormant Inactive

Landslide body

Fall

Slide

Flow 1955 Complex PtPresent‐day Shallow landslide Landslides

Calcarenite

Sand and sandstone Sandstone and conglomerate

Phyllite

Altilia Altilia Sand (and soils)

Gneiss

Iassa Mancarelli Geological map Calcarenite Ogliara Sandstone

Conglomerate

Ogliara site Schist and phyllite Geological map Garcito

Garcito Highway Piano d’Infante site Geological map Fiego

Legend

Sand (and soils)

Road Scarp edge Gabions Highway Fiego Bulkhead piles site Soils

Entisols Inceptisols Mollisols Alfisols Pedological discontinuities Fiego site F2

F3 Perched water table Some physical and rheological data

Clay (%) BD (g cm‐3) (ρa) 40,0 1,60 35,0 1,40 30,0 1,20 25,0 1,00 20,0 0,80 15,0 0,60 10,0 0,40 505,0 0200,20 0,0 0,00

A A A A

CB CB AB AB AB AB Bw Bw Bw Bw

2 2

B/A B/A

Bg4 Bg4 Bg3 Bg3 Bg1 Bg1

Btg2 Btg2 2Bt2 2Bt2 2Bt1 2Bt1 2Bt2 2Bt2 2Bt1 2Bt1 2Bt1 2Bt2 2Bt1 2Bt2 2Bt1 2Bt1 2Bt2 2Bt2 2Bt3 2Bt3

GPI GPI F1 F1 F1 F1 2Btg3 2Btg3 F3 F3 Tasca Tasca F2 F2

PD PD F2 F2 F1 F1 F1 F1 F1 F1

GPI GPI F1 F1 F3 F3 F3 F3 F2 F2 F2 F2 PD PD PD PD PD PD A A

GPI GPI GPI GPI F3 F3 D D PP PP

WL% IP% 50 30 45 IP = WL - WP 40 25 35 20 30 25 15 20 15 10 10 5 5 0

0 A A

A A CB AB AB w w

Bw t1 t2 t1 t2 t1 t2 Bw t1 t2 t3

2 tg3 tg2

/A Bt1 Bt2 Bt1 Bt2 Bt1 Bt2 Bt1 Bt2 Bt3 g1 g2 g3 g4 g3 I

CB B/A sca

Bg1 Bg3 Bg4 AB AB ca PI I BB BB

tt tt

BB BB BB BB BB BB 11 BB BB BB 11 BB BB

22 22 22 22 22 22 22 22 22 BB

BB BB BB 33 PP

G F B 2 2 2 2 2 2 F 2 2 2 2 F Ta

P G F1 F2

F1 F1 F1 F1 GP 2B F3 Tas F2

PD F1 F2 F2 F3 F3 F2 F1 F1 F1

GPI PD PD PD A F1 F2 F2 F3 F3

GPI GPI F3 PD PD PD A

GPI GPI F3 PD PD Landslide susceptibility map

Conditional UCUs Analysis tors cc ItIntersecti on of predisposing Landslide factors susceptibility

osing fa Training set map pp (50%) Landslides Predis

Testing set Validation of landslide (50%) susceptibility map

Thematic layers subdivided into classes UCU = Unique Condition Unit

EtiEstimati on ofthf the probabilit y to obtai n a certitain ditdensity of lan ds lides per each UCU, i.e. the probability (%) that a landslide could occur in that specific area Landslide susceptibility map UCUs map construction

7030 UCUs Landslide susceptibility map

Relationship between the UCUs map and the landslide map

Landslide

Training set

Testing set

Highway Landslide susceptibility map

Distribution of susceptibility classes

Validation of the susceptibility map Susceptibility class Susceptibility Landslide Area (()%) Low class testing set (%) Moderate Very high 933 High 80% Very high High 29 47 Highway Moderate 24 17 Low 38 3 Correct classification: most of the landslides is included in the 2 highest susceptibility classes High probability (80%) that a landslide could occur in the red-orange areas (The validation set mimics future landslides) Landslide spatial risk Independent of magnitude and Spatial risk class return period Low Susceptibility of landslides Moderate

Low High Moderate Very High High Very high Highway Vulnerable objects (highway) are overlain on the susceptibility map

Spatial Risk km % Very high 2.9 10.4 High 7.5 26.8 Moderate 828.2 29.4 Low 9.3 33.4 Relatively low spatial risk because vulnerable highway tracks are not included in higher‐risk areas or potential landslides will not involve them (e.g., viaducts) Conclusive remarks

Prominent role of litho-structural (fault scarps, spatial arrangement of different lithologies) and geomorphological features (high local relief, steep slopes, stream dissection) as predisposing factors of landslides and their types

Morphological and physical discontinuities caused on geological terrains by weathering and pedogenetic processes (soil horizon differentiation, argillification, oxidation, development of pedogenic structure, clay illuviation) interfingered with geomorphic dynamics (truncation by erosion, burial by younger sediments, e.g., colluvial material, slope deposits, landslide debris)

Corresppgonding changes in ppyhysical and geomechanical ppproperties of rock types (e.g., particle size distribution, liquid and plastic limits, bulk density, organic carbon content, porosity) in depth, evidenced by laboratory analyses

High reliability of the landslide susceptibility and spatial risk assessment along the pilot section of the A3 highway between Cosenza Sud and Altilia (N Calabria) using the UCUs (Unique Condition Units) method and the conditional analysis Thank you for your attention !