Advanced Search

Indexed by SCI、CA、РЖ、PA、CSA、ZR、etc .

Volume 31 Issue 2
Apr.  2020
Turn off MathJax
Article Contents

Massimo Conforti, Fabio Ietto. Influence of Tectonics and Morphometric Features on the Landslide Distribution: A Case Study from the Mesima Basin (Calabria, South Italy). Journal of Earth Science, 2020, 31(2): 393-409. doi: 10.1007/s12583-019-1231-z
Citation: Massimo Conforti, Fabio Ietto. Influence of Tectonics and Morphometric Features on the Landslide Distribution: A Case Study from the Mesima Basin (Calabria, South Italy). Journal of Earth Science, 2020, 31(2): 393-409. doi: 10.1007/s12583-019-1231-z

Influence of Tectonics and Morphometric Features on the Landslide Distribution: A Case Study from the Mesima Basin (Calabria, South Italy)

doi: 10.1007/s12583-019-1231-z
More Information
  • Identifying the instability areas provides useful information about the recognition of the vulnerable zones and,thus,helps to potentially decrease the harm to the infrastructure and the hazard conditions in inhabited areas. In this regard,morphometric parameters and tectonic setting are widely employed in mapping,modelling and understanding of instability processes. The present study is aimed to analyse the combined effects of slope morphometry (slope gradient,slope curvature,local relief),of lithology,of drainage density and of tectonic setting on the distribution of landslides. The study area is located in the Mesima Basin that lies in the central part of the Calabria region (southern Italy). The morphometric analysis was carried out by geographic information system (GIS) techniques,whereas the geomorphic attributes were computed by a digital elevation model (DEM). The recognized landslides and faults were digitized and stored in a GIS geo-database that allowed the construction of relative density maps. A total of 1 991 landslides and 231 tectonic lineaments were recognized and mapped. The distribution of the collected data suggests that the occurrence of landslides is not random. Indeed,the research highlights as the lithology,the fault density,the slope gradient and the local relief play an important role in determining the landslide occurrence. The used approach is aimed to reinforce the knowledge about the validity of the application of morphometric analysis to the landslide susceptibility. The Mesima Basin is a poorly studied area of the Calabria from a geomorphological viewpoint. Indeed,previous researches focused mainly on geological and on tectonic aspects,as well as on instability phenomena in the Mesima surroundings. Thus,this paper takes a step forward with respect to previous studies because it augments the knowledge about the relationship between faults,morphometric features and the occurrence of landslide.
  • 加载中
  • Agliardi, F., Zanchi, A., Crosta, G. B., 2009. Tectonic vs. Gravitational Morphostructures in the Central Eastern Alps (Italy):Constraints on the Recent Evolution of the Mountain Range. Tectonophysics, 474(1/2):250-270. https://doi.org/10.1016/j.tecto.2009.02.019 doi:  10.1016/j.tecto.2009.02.019
    Altın, B. T., Gökkaya, E., 2018. Assessment of Landslide-Triggering Factors and Occurrence Using Morphometric Parameters in Geyraz Basin, Tokat, Northern Turkey. Environmental Earth Sciences, 77(4):126. https://doi.org/10.1007/s12665-018-7315-8 doi:  10.1007/s12665-018-7315-8
    Amodio-Morelli, L., Bonardi, G., Colonna, V., et al., 1976. L'Arco Calabro-Peloritano Nell'orogene Appenninico-Maghrebide. Mem. Soc. Geol. Ital., 17:1-60 (in Italian)
    Antonioli, F., Ferranti, L., Fontana, A., et al., 2009. Holocene Relative Sea-Level Changes and Vertical Movements along the Italian and Istrian Coastlines. Quaternary International, 206(1/2):102-133. https://doi.org/10.1016/j.quaint.2008.11.008 doi:  10.1016/j.quaint.2008.11.008
    Antonioli, F., Ferranti, L., Lambeck, K., et al., 2006. Late Pleistocene to Holocene Record of Changing Uplift Rates in Southern Calabria and Northeastern Sicily (Southern Italy, Central Mediterranean Sea). Tectonophysics, 422(1-4):23-40. https://doi.org/10.1016/j.tecto.2006.05.003 doi:  10.1016/j.tecto.2006.05.003
    Antronico, L., Borrelli, L., Coscarelli, R., 2017. Recent Damaging Events on Alluvial Fans along a Stretch of the Tyrrhenian Coast of Calabria (Southern Italy). Bulletin of Engineering Geology and the Environment, 76(4):1399-1416. https://doi.org/10.1007/s10064-016-0922-2 doi:  10.1007/s10064-016-0922-2
    Aringoli, D., Cavitolo, P., Farabollini, P., et al., 2014. Morphotectonic Characterization of the Quaternary Intermontane Basins of the Umbria-Marche Apennines (Italy). Rendiconti Lincei, 25(S2):111-128. https://doi.org/10.1007/s12210-014-0330-0 doi:  10.1007/s12210-014-0330-0
    Barca, D., Cirrincione, R., de Vuono, E., et al., 2010. The Triassic Rift System in the Northern Calabrian-Peloritani Orogen:Evidence from Basaltic Dyke Magmatism in the San Donato Unit. Period Miner., 79(2):61-72
    Bonardi, G., de Vivo, B., Giunta, G., et al., 1982. Mineralizzazioni Dell'arco Calabro Peloritano. Ipotesi Genetiche e Quadro Evolutivo. Boll. Soc. Geol. Ital., 101:141-155 (in Italian)
    Borrelli, L., Antronico, L., Gullà, G., et al., 2014. Geology, Geomorphology and Dynamics of the 15 February 2010 Maierato Landslide (Calabria, Italy). Geomorphology, 208:50-73. https://doi.org/10.1016/j.geomorph.2013.11.015 doi:  10.1016/j.geomorph.2013.11.015
    Borrelli, L., Gullà, G., 2017. Tectonic Constraints on a Deep-Seated Rock Slide in Weathered Crystalline Rocks. Geomorphology, 290:288-316. https://doi.org/10.1016/j.geomorph.2017.04.025 doi:  10.1016/j.geomorph.2017.04.025
    Borrelli, L., Perri, F., Critelli, S., et al., 2012. Minero-Petrographical Features of Weathering Profiles in Calabria, Southern Italy. Catena, 92:196-207. https://doi.org/10.1016/j.catena.2012.01.003 doi:  10.1016/j.catena.2012.01.003
    Boschi, E. G., Ferrari, P., Gasperini, E., et al., 1995. Catalogo dei Forti Terremoti in Italia dal 461 a.C. al 1980. Istituto Nazionale di Geofisica-S.G.A., Roma. 973
    Bozzano, F., Lenti, L., Martino, S., et al., 2011. Earthquake Triggering of Landslides in Highly Jointed Rock Masses:Reconstruction of the 1783 Scilla Rock Avalanche (Italy). Geomorphology, 129(3/4):294-308. https://doi.org/10.1016/j.geomorph.2011.02.025 doi:  10.1016/j.geomorph.2011.02.025
    Bucci, F., Santangelo, M., Cardinali, M., et al., 2016. Landslide Distribution and Size in Response to Quaternary Fault Activity:The Peloritani Range, NE Sicily, Italy. Earth Surface Processes and Landforms, 41(5):711-720. https://doi.org/10.1002/esp.3898 doi:  10.1002/esp.3898
    Calcaterra, D., Parise, M., 2000. Debris-Flow-Related Fans in Weathered Crystalline Rocks and the Potential Hazard in Calabria, Italy. In: Proc 2nd Intern Conf. on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment, 16-18 August, Taipei. 203-211
    Calcaterra, D., Parise, M., 2005. Landslide Types and Their Relationships with Weathering in a Calabrian Basin, Southern Italy. Bulletin of Engineering Geology and the Environment, 64(2):193-207. https://doi.org/10.1007/s10064-004-0262-5 doi:  10.1007/s10064-004-0262-5
    Calcaterra, D., Parise, M., 2010. Weathering as a Predisposing Factor to Slope Movements:An Introduction. Geological Society, London, Engineering Geology Special Publications, 23(1):1-4. https://doi.org/10.1144/egsp23.1 doi:  10.1144/egsp23.1
    Capolongo, D., Cecaro, G., Giano, S. I., et al., 2005. Structural Control on Drainage Network of the South-Western Side of the Agri River Upper Valley (Southern Apennines, Italy). Supplementi di Geografia Fisica e Dinamica Quaternaria, 28(2):169-180 http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=7c37438beb713d317a21a5dcf483c71a
    Carlini, M., Chelli, A., Vescovi, P., et al., 2016. Tectonic Control on the Development and Distribution of Large Landslides in the Northern Apennines (Italy). Geomorphology, 253:425-437. https://doi.org/10.1016/j.geomorph.2015.10.028 doi:  10.1016/j.geomorph.2015.10.028
    Carrara, A., Catalano, E., Sorriso Valvo, M., et al., 1977. Landslide Morphometry and Typology in Two Zones, Calabria, Italy. Bulletin of the International Association of Engineering Geology, 16(1):8-13. https://doi.org/10.1007/bf02591433 doi:  10.1007/bf02591433
    Casmez, 1971. Carta Geologica della Calabria (in Scale 1/25 000). Poligrafica & Carte Valori, Ercolano, Napoli (in Italian)
    Catalano, S., de Guidi, G., Monaco, C., et al., 2008. Active Faulting and Seismicity along the Siculo-Calabrian Rift Zone (Southern Italy). Tectonophysics, 453(1/2/3/4):177-192. https://doi.org/10.1016/j.tecto.2007.05.008 doi:  10.1016/j.tecto.2007.05.008
    Cendrero, A., Dramis, F., 1996. The Contribution of Landslides to Landscape Evolution in Europe. Geomorphology, 15(3/4):191-211. https://doi.org/10.1016/0169-555x(95)00070-l doi:  10.1016/0169-555x(95)00070-l
    Chiodo, G., Dramis, F., Gervasi, A., et al., 1999. Frane Sismo-Indotte E Pericolosità di Sito: Primi Risultati Dello Studio Degli Effetti di Forti Terremoti storici in Calabria Centro-Settentrionale. Atti 18° Conv. Ann. Gruppo Naz. Geofis. Terra Solida, Roma (in Italian)
    Ciccacci, S., D'alessandro, L., Fredi, P., et al., 1992. Relations between Morphometric Characteristics and Denudational Processes in Some Drainage Basins of Italy. Zeitschrift fuer Geomorphologic, 36(1):53-57
    Conforti, M., Buttafuoco, G., 2017. Assessing Space-Time Variations of Denudation Processes and Related Soil Loss from 1955 to 2016 in Southern Italy (Calabria Region). Environmental Earth Sciences, 76(13):457. https://doi.org/10.1007/s12665-017-6786-3 doi:  10.1007/s12665-017-6786-3
    Conforti, M., Ietto, F., 2019. An Integrated Approach to Investigate Slope Instability Affecting Infrastructures. Bulletin of Engineering Geology and the Environment, 78(4):2355-2375. https://doi.org/10.1007/s10064-018-1311-9 doi:  10.1007/s10064-018-1311-9
    Conforti, M., Pascale, S., Pepe, M., et al., 2013. Denudation Processes and Landforms Map of the Camastra River Catchment (Basilicata-South Italy). Journal of Maps, 9(3):444-455. https://doi.org/10.1080/17445647.2013.804797 doi:  10.1080/17445647.2013.804797
    Conforti, M., Muto, F., Rago, V., et al., 2014a. Landslide Inventory Map of North-Eastern Calabria (South Italy). Journal of Maps, 10(1):90-102. https://doi.org/10.1080/17445647.2013.852142 doi:  10.1080/17445647.2013.852142
    Conforti, M., Pascale, S., Robustelli, G., et al., 2014b. Evaluation of Prediction Capability of the Artificial Neural Networks for Mapping Landslide Susceptibility in the Turbolo River Catchment (Northern Calabria, Italy). Catena, 113:236-250. https://doi.org/10.1016/j.catena.2013.08.006 doi:  10.1016/j.catena.2013.08.006
    Conforti, M., Pascale, S., Sdao, F., 2015. Mass Movements Inventory Map of the Rubbio Stream Catchment (Basilicata-South Italy). Journal of Maps, 11(3):454-463. https://doi.org/10.1080/17445647.2014.924038 doi:  10.1080/17445647.2014.924038
    Conforti, M., Rago, V., Muto, F., et al., 2016. GIS-Based Statistical Analysis for Assessing Shallow-Landslide Susceptibility along the Highway in Calabria (Southern Italy). Rendiconti Online della Società Geologica Italiana, 39:155-158. https://doi.org/10.3301/rol.2015.184 doi:  10.3301/rol.2015.184
    Conforti, M., Robustelli, G., Muto, F., et al., 2012. Application and Validation of Bivariate GIS-Based Landslide Susceptibility Assessment for the Vitravo River Catchment (Calabria, South Italy). Natural Hazards, 61(1):127-141. https://doi.org/10.1007/s11069-011-9781-0 doi:  10.1007/s11069-011-9781-0
    Cotecchia, V., Guerricchio, A., Melidoro, G., 1986. The Geomorphogenetic Crisis Triggered by the 1783 Earthquake in Calabria (Southern Italy). Proceedings of the International Symposium on Engineering Geology Problems in Seismic Areas, Bari, Italy, 6: 245-304
    Cruden, D. M., Varnes, D. J., 1996. Landslide Types and Processes. In: Turner, A. K., Schuster, R. L., eds., Landslides: Investigation and Mitigation. National Academy Press, Washington
    DC Cucci, L., Tertulliani, A., 2006. I Terrazzi Marini Nell'area di Capo Vaticano (Arco Calabro):Solo un Record di Sollevamento Regionale o Anche di Deformazione Cosismica? II Quaternario, 19:89-101 (in Italian)
    Della Seta, M., del Monte, M., Fredi, P., et al., 2004. Quantitative Morphotectonic Analysis as a Tool for Detecting Deformation Patterns in Soft-Rock Terrains:A Case Study from the Southern Marches, Italy/Analyse Morphotectonique Quantitative Dans Une Province Lithologique Enregistrant Mal Les Déformations:Les Marches Méridionales, Italie. Géomorphologie:Relief, Processus, Environnement, 10(4):267-284. https://doi.org/10.3406/morfo.2004.1224 doi:  10.3406/morfo.2004.1224
    Dewey, J. F., Helman, M. L., Turco, E., et al., 1989. Kinematics of the Western Mediterranean. In: Coward, M. P., Dietrich, D., Park, R. G., eds., Alpine Tectonics. Geological Society London Special Publications, 45: 265-283
    Dramis, F., Sorriso-Valvo, M., 1994. Deep-Seated Gravitational Slope Deformations, Related Landslides and Tectonics. Engineering Geology, 38(3/4):231-243. https://doi.org/10.1016/0013-7952(94)90040-x doi:  10.1016/0013-7952(94)90040-x
    Fabbri, A., Ghisetti, F., Vezzani, L., 1980. The Peloritani-Calabria Range and the Gioia Basin in the Calabrian Arc (Southern Italy):Relationships between Land and Marine Data. Geol Romana, 19:131-150
    Ferranti, L., Antonioli, F., Mauz, B., et al., 2006. Markers of the Last Interglacial Sea-Level High Stand along the Coast of Italy:Tectonic Implications. Quaternary International, 145-146:30-54. https://doi.org/10.1016/j.quaint.2005.07.009 doi:  10.1016/j.quaint.2005.07.009
    Galadini, F., 2006. Quaternary Tectonics and Large-Scale Gravitational Deformations with Evidence of Rock-Slide Displacements in the Central Apennines (Central Italy). Geomorphology, 82(3/4):201-228. https://doi.org/10.1016/j.geomorph.2006.05.003 doi:  10.1016/j.geomorph.2006.05.003
    Galli, P., Bosi, V., 2002. Paleoseismology along the Cittanova Fault:Implications for Seismotectonics and Earthquake Recurrence in Calabria (Southern Italy). Journal of Geophysical Research, 107(B3):1-19. https://doi.org/10.1029/2001jb000234 doi:  10.1029/2001jb000234
    Galli, P., Galadini, F., Pantosti, D., 2008. Twenty Years of Paleoseismology in Italy. Earth-Science Reviews, 88(1/2):89-117. https://doi.org/10.1016/j.earscirev.2008.01.001 doi:  10.1016/j.earscirev.2008.01.001
    Ghisetti, F., 1980. Evoluzione Tettonica dei Principali Sistemi di Faglie Della Calabria Centrale. Boll. Soc. Geol. Ital., 98:387-430 (in Italian)
    Ghisetti, F., 1981. Upper Pliocene-Pleistocene Uplift Rates as Indicators of Neotectonic Pattern:An Example from Southern Calabria (Italy). Z. Geomorphologie, 40:93-118
    Ghisetti, F., Vezzani, L., 1982. Different Styles of Deformation in the Calabrian Arc (Southern Italy):Implications for a Seismotectonic Zoning. Tectonophysics, 85(3/4):149-165. https://doi.org/10.1016/0040-1951(82)90101-9 doi:  10.1016/0040-1951(82)90101-9
    Glade, T., Anderson, M., Crozier, M. J., eds., 2005. Landslide Hazard and Risk. Wiley, New York. 824
    Graessner, T., Schenk, V., Bröcker, M., et al., 2002. Geochronological Constraints on the Timing of Granitoid Magmatism, Metamorphism and Post-Metamorphic Cooling in the Hercynian Crustal Cross-Section of Calabria. Journal of Metamorphic Geology, 18(4):409-421. https://doi.org/10.1046/j.1525-1314.2000.00267.x doi:  10.1046/j.1525-1314.2000.00267.x
    Guerricchio, A., 2005. Tectonics, Deep Seated Gravitational Slope Deformations (DSGSDs) and Large Landslides in the Calabrian Region (Southern Italy). Gior. Geol. Appl., 1:73-90
    Huang, X. J., Niemann, J. D., 2006. Modelling the Potential Impacts of Groundwater Hydrology on Long-Term Drainage Basin Evolution. Earth Surface Processes and Landforms, 31(14):1802-1823. https://doi.org/10.1002/esp.1369 doi:  10.1002/esp.1369
    Hurtrez, J.-E., Sol, C., Lucazeau, F., 1999. Effect of Drainage Area on Hypsometry from an Analysis of Small-Scale Drainage Basins in the Siwalik Hills (Central Nepal). Earth Surface Processes and Landforms, 24(9):799-808. https://doi.org/10.1002/(sici)1096-9837(199908)24:9<799::aid-esp12>3.0.co; 2-4 doi:  10.1002/(sici)1096-9837(199908)24:9<799::aid-esp12>3.0.co;2-4
    Ietto, F., Bernasconi, M. P., 2005. The Cliff Bordering the Northwestern Margin of the Mesima Basin (Southern Calabria) is of Pleistocene Age. Geogr. Fis. Dinam. Quart., 28:205-210 http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=7691fa767522e71cb009d7821207baa9
    Ietto, F., Bernasconi, M. P., 2016. Evidences of Fossil Landslides from the Lower Pleistocene on the Northwestern Margin of the Mesima Basin (Southern Calabria, Italy). Rendiconti Online della Società Geologica Italiana, 38:65-68. https://doi.org/10.3301/rol.2016.19 doi:  10.3301/rol.2016.19
    Ietto, F., Salvo, F., Cantasano, N., 2014. The Quality of Life Conditioning with Reference to the Local Environmental Management:A Pattern in Bivona Country (Calabria, Southern Italy). Ocean & Coastal Management, 102:340-349. https://doi.org/10.1016/j.ocecoaman.2014.10.014 doi:  10.1016/j.ocecoaman.2014.10.014
    Ietto, F., Donato, F. F., Ietto, A., 2007. Recent Reverse Faults and Landslides in Granitoid Weathered Profiles, Serre Mountains (Southern Calabria, Italy). Geomorphology, 87(3):196-206. https://doi.org/10.1016/j.geomorph.2006.03.042 doi:  10.1016/j.geomorph.2006.03.042
    Ietto, F., Perri, F., 2015. Flash Flood Event (October 2010) in the Zinzolo Catchment (Calabria, Southern Italy). Rendiconti Online della Società Geologica Italiana, 35:170-173. https://doi.org/10.3301/rol.2015.92 doi:  10.3301/rol.2015.92
    Ietto, F., Perri, F., Cella, F., 2016. Geotechnical and Landslide Aspects in Weathered Granitoid Rock Masses (Serre Massif, Southern Calabria, Italy). Catena, 145:301-315. https://doi.org/10.1016/j.catena.2016.06.027 doi:  10.1016/j.catena.2016.06.027
    Ietto, F., Perri, F., Cella, F., 2018. Weathering Characterization for Landslides Modeling in Granitoid Rock Masses of the Capo Vaticano Promontory (Calabria, Italy). Landslides, 15(1):43-62. https://doi.org/10.1007/s10346-017-0860-5 doi:  10.1007/s10346-017-0860-5
    Ietto, F., Perri, F., Fortunato, G., 2014. Lateral Spreading Phenomena and Weathering Processes from the Tropea Area (Calabria, Southern Italy). Environmental Earth Sciences, 73(8):4595-4608. https://doi.org/10.1007/s12665-014-3745-0 doi:  10.1007/s12665-014-3745-0
    Jacques, E., Monaco, C., Tapponnier, P., et al., 2001. Faulting and Earthquake Triggering during the 1783 Calabria Seismic Sequence. Geophysical Journal International, 147(3):499-516. https://doi.org/10.1046/j.0956-540x.2001.01518.x doi:  10.1046/j.0956-540x.2001.01518.x
    Keaton, J. R., DeGraff, J. V., 1996. Surface Observation and Geologic Mapping. In: Turner, A. K., Schuster, R. L., eds., Landslides: Investigation and Mitigation. National Academy Press, Washington, DC
    Keefer, D. K., 2002. Investigating Landslides Caused by Earthquakes——A Historical Review. Surv. Geophys, 23(6):473-510 doi:  10.1023/A:1021274710840
    Keller, E. A., Pinter, N., 2002. Active Tectonics: Earthquakes, Uplift, and Landscape. Prentice Hall, New Jersey. 432
    Khazai, B., Sitar, N., 2004. Evaluation of Factors Controlling Earthquake-Induced Landslides Caused by Chi-Chi Earthquake and Comparison with the Northridge and Loma Prieta Events. Engineering Geology, 71(1/2):79-95. https://doi.org/10.1016/s0013-7952(03)00127-3 doi:  10.1016/s0013-7952(03)00127-3
    Klose, M., Damm, B., Terhorst, B., 2015. Landslide Cost Modeling for Transportation Infrastructures:A Methodological Approach. Landslides, 12(2):321-334. https://doi.org/10.1007/s10346-014-0481-1 doi:  10.1007/s10346-014-0481-1
    Kusre, B. C., 2013. Hypsometric Analysis and Watershed Management of Diyung Watershed in North Eastern India. Journal of the Geological Society of India, 82(3):262-270. https://doi.org/10.1007/s12594-013-0148-x doi:  10.1007/s12594-013-0148-x
    Larsen, I. J., Montgomery, D. R., 2012. Landslide Erosion Coupled to Tectonics and River Incision. Nature Geoscience, 5(7):468-473. https://doi.org/10.1038/ngeo1479 doi:  10.1038/ngeo1479
    Lee, S., Dan, N. T., 2005. Probabilistic Landslide Susceptibility Mapping in the Lai Chau Province of Vietnam:Focus on the Relationship between Tectonic Fractures and Landslides. Environmental Geology, 48(6):778-787. https://doi.org/10.1007/s00254-005-0019-x doi:  10.1007/s00254-005-0019-x
    Lee, S., Min, K., 2001. Statistical Analysis of Landslide Susceptibility at Yongin, Korea. Environmental Geology, 40(9):1095-1113. https://doi.org/10.1007/s002540100310 doi:  10.1007/s002540100310
    Liu, Z. F., Colin, C., Huang, W., et al., 2007. Climatic and Tectonic Controls on Weathering in South China and Indochina Peninsula:Clay Mineralogical and Geochemical Investigations from the Pearl, Red, and Mekong Drainage Basins. Geochemistry, Geophysics, Geosystems, 8(5):1-18. https://doi.org/10.1029/2006gc001490 doi:  10.1029/2006gc001490
    Lucà, F., Robustelli, G., Conforti, M., et al., 2011. Geomorphological Map of the Crotone Province (Calabria, South Italy). Journal of Maps, 7(1):375-390. https://doi.org/10.4113/jom.2011.1190 doi:  10.4113/jom.2011.1190
    Malamud, B. D., Turcotte, D. L., Guzzetti, F., et al., 2004. Landslide Inventories and Their Statistical Properties. Earth Surface Processes and Landforms, 29(6):687-711. https://doi.org/10.1002/esp.1064 doi:  10.1002/esp.1064
    Malik, J. N., Mohanty, C., 2007. Active Tectonic Influence on the Evolution of Drainage and Landscape:Geomorphic Signatures from Frontal and Hinterland Areas along the Northwestern Himalaya, India. Journal of Asian Earth Sciences, 29(5/6):604-618. https://doi.org/10.1016/j.jseaes.2006.03.010 doi:  10.1016/j.jseaes.2006.03.010
    Mancini, F., Ceppi, C., Ritrovato, G., 2010. GIS and Statistical Analysis for Landslide Susceptibility Mapping in the Daunia Area, Italy. Natural Hazards and Earth System Science, 10(9):1851-1864. https://doi.org/10.5194/nhess-10-1851-2010 doi:  10.5194/nhess-10-1851-2010
    Mayer, L., Menichetti, M., Nesci, O., et al., 2003. Morphotectonic Approach to the Drainage Analysis in the North Marche Region, Central Italy. Quaternary International, 101-102:157-167. https://doi.org/10.1016/s1040-6182(02)00098-8 doi:  10.1016/s1040-6182(02)00098-8
    Miyauchi, T., Dai Pra, G., Sylos Labini, S., 1994. Geochronology of Pleistocene Marine Terraces and Regional Tectonics in Tyrrhenian Coast of South Calabria, Italy. II Quaternario, 7:17-34
    Moglen, G. E., Eltahir, E. A. B., Bras, R. L., 1998. On the Sensitivity of Drainage Density to Climate Change. Water Resources Research, 34(4):855-862. https://doi.org/10.1029/97wr02709 doi:  10.1029/97wr02709
    Molin, P., Fubelli, G., Dramis, F., 2012. The Tectonic Influence on Drainage Evolution in an Uplifting Area: The Case of the Sila Greca (Calabria, Italy), Geogr. Fis. Dinam. Quart., 35: 49-60
    Monaco, C., Tortorici, L., 2000. Active Faulting in the Calabrian Arc and Eastern Sicily. Journal of Geodynamics, 29(3/4/5):407-424. https://doi.org/10.1016/s0264-3707(99)00052-6 doi:  10.1016/s0264-3707(99)00052-6
    Oguchi, T., 1997. Drainage Density and Relative Relief in Humid Steep Mountains with Frequent Slope Failure. Earth Surface Processes and Landforms, 22(2):107-120. https://doi.org/10.1002/(sici)1096-9837(199702)22:2<107::aid-esp680>3.3.co; 2-l doi:  10.1002/(sici)1096-9837(199702)22:2<107::aid-esp680>3.3.co;2-l
    Ozdemir, H., Bird, D., 2009. Evaluation of Morphometric Parameters of Drainage Networks Derived from Topographic Maps and DEM in Point of Floods. Environmental Geology, 56(7):1405-1415. https://doi.org/10.1007/s00254-008-1235-y doi:  10.1007/s00254-008-1235-y
    Parise, M., Sorriso-Valvo, M., Tansi, C., 1997. Mass Movements Related to Tectonics in the Aspromonte Massif (Southern Italy). Engineering Geology, 47(1/2):89-106. https://doi.org/10.1016/s0013-7952(96)00125-1 doi:  10.1016/s0013-7952(96)00125-1
    Peckham, R. J., Jordan, G., 2007. Digital Terrain Modeling. Development and Applications in a Policy Support Environment. Series: Lecture Notes in Geoinformation and Cartography. Springer, Berlin
    Pellegrino, A., Prestininzi, A., 2007. Impact of Weathering on the Geomechanical Properties of Rocks along Thermal-Metamorphic Contact Belts and Morpho-Evolutionary Processes:The Deep-Seated Gravitational Slope Deformations of Mt. Granieri-Salincriti (Calabria-Italy). Geomorphology, 87(3):176-195. https://doi.org/10.1016/j.geomorph.2006.03.032 doi:  10.1016/j.geomorph.2006.03.032
    Pérez-Peña, J. V., Azor, A., Azañón, J. M., et al., 2010. Active Tectonics in the Sierra Nevada (Betic Cordillera, SE Spain):Insights from Geomorphic Indexes and Drainage Pattern Analysis. Geomorphology, 119(1/2):74-87. https://doi.org/10.1016/j.geomorph.2010.02.020 doi:  10.1016/j.geomorph.2010.02.020
    Perri, F., Ietto, F., le Pera, E., et al., 2014. Weathering Processes Affecting Granitoid Profiles of Capo Vaticano (Calabria, Southern Italy) Based on Petrographic, Mineralogic and Reaction Path Modelling Approaches. Geological Journal, 51(3):368-386. https://doi.org/10.1002/gj.2635 doi:  10.1002/gj.2635
    Petrea, D., Stefan, B., Roșca, S., et al., 2014. The Determination of the Landslide Occurrence Probability by GIS Spatial Analysis of the Land Morphometric Characteristics (Case Study:The Transylvanian Plateau). Carpathian Journal of Earth and Environmental Sciences, 9(2):91-102 (in Arabic with English Abstract)
    Pike, R. J., Wilson, S. E., 1971. Elevation-Relief Ratio, Hypsometric Integral, and Geomorphic Area-Altitude Analysis. Geological Society of America Bulletin, 82(4):1079. https://doi.org/10.1130/0016-7606(1971)82[1079:erhiag]2.0.co; 2 doi:  10.1130/0016-7606(1971)82[1079:erhiag]2.0.co;2
    Pirrotta, C., Barbano, M. S., Monaco, C., 2016. Evidence of Active Tectonics in Southern Calabria (Italy) by Geomorphic Analysis:The Examples of the Catona and Petrace Rivers. Italian Journal of Geosciences, 135(2):1-45. https://doi.org/10.3301/ijg.2015.20 doi:  10.3301/ijg.2015.20
    Radaideh, O. M. A., Grasemann, B., Melichar, R., et al., 2016. Detection and Analysis of Morphotectonic Features Utilizing Satellite Remote Sensing and GIS:An Example in SW Jordan. Geomorphology, 275:58-79. https://doi.org/10.1016/j.geomorph.2016.09.033 doi:  10.1016/j.geomorph.2016.09.033
    Rapisarda, F., 2009. Morphometric and Landsliding Analyses in Chain Domain:The Roccella Basin, NE Sicily, Italy. Environmental Geology, 58(7):1407-1417. https://doi.org/10.1007/s00254-008-1643-z doi:  10.1007/s00254-008-1643-z
    Ribolini, A., Spagnolo, M., 2008. Drainage Network Geometry Versus Tectonics in the Argentera Massif (French-Italian Alps). Geomorphology, 93(3/4):253-266. https://doi.org/10.1016/j.geomorph.2007.02.016 doi:  10.1016/j.geomorph.2007.02.016
    Roda-Boluda, D. C., D'Arcy, M., McDonald, J., et al., 2018. Lithological Controls on Hillslope Sediment Supply:Insights from Landslide Activity and Grain Size Distributions. Earth Surface Processes and Landforms, 43(5):956-977. https://doi.org/10.1002/esp.4281 doi:  10.1002/esp.4281
    Saha, A. K., Gupta, R. P., Arora, M. K., 2002. GIS-Based Landslide Hazard Zonation in the Bhagirathi (Ganga) Valley, Himalayas. International Journal of Remote Sensing, 23(2):357-369. https://doi.org/10.1080/01431160010014260 doi:  10.1080/01431160010014260
    Sanchez, G., Rolland, Y., Corsini, M., et al., 2010. Relationships between Tectonics, Slope Instability and Climate Change:Cosmic Ray Exposure Dating of Active Faults, Landslides and Glacial Surfaces in the SW Alps. Geomorphology, 117(1/2):1-13. https://doi.org/10.1016/j.geomorph.2009.10.019 doi:  10.1016/j.geomorph.2009.10.019
    Santangelo, M., Gioia, D., Cardinali, M., et al., 2013. Interplay between Mass Movement and Fluvial Network Organization:An Example from Southern Apennines, Italy. Geomorphology, 188:54-67. https://doi.org/10.1016/j.geomorph.2012.12.008 doi:  10.1016/j.geomorph.2012.12.008
    Scotti, V. N., Molin, P., Faccenna, C., et al., 2014. The Influence of Surface and Tectonic Processes on Landscape Evolution of the Iberian Chain (Spain):Quantitative Geomorphological Analysis and Geochronology. Geomorphology, 206:37-57. https://doi.org/10.1016/j.geomorph.2013.09.017 doi:  10.1016/j.geomorph.2013.09.017
    Sorriso-Valvo, M., Tansi, C., Antronico, L., 1996. Relazioni tra Frane, Forme del Rilievo e Strutture Tettoniche Nella Media Valle del Fiume Crati (Calabria). Geogr Fis Dinam Quater, 19:107-117 (in Italian)
    Sreedevi, P. D., Owais, S., Khan, H. H., et al., 2009. Morphometric Analysis of a Watershed of South India Using SRTM Data and GIS. Journal of the Geological Society of India, 73(4):543-552. https://doi.org/10.1007/s12594-009-0038-4 doi:  10.1007/s12594-009-0038-4
    Stark, C. P., Hovius, N., 2001. The Characterization of Landslide Size Distributions. Geophysical Research Letters, 28(6):1091-1094. https://doi.org/10.1029/2000gl008527 doi:  10.1029/2000gl008527
    Strahler, A. N., 1952. Hypsometric (Area-Altitude) Analysis of Erosional Topography. Geological Society of America Bulletin, 63(11):1117. https://doi.org/10.1130/0016-7606(1952)63[1117:haaoet]2.0.co; 2 doi:  10.1130/0016-7606(1952)63[1117:haaoet]2.0.co;2
    Strahler, A. N., 1964. Quantitative Geomorphology of Drainage Basins and Channel Networks. In: Chow, V. T., ed., Handbook of Applied Hydrology, Section 4, Mac Graw-Hill, New York
    Tansi, C., Muto, F., Critelli, S., et al., 2007. Neogene-Quaternary Strike-Slip Tectonics in the Central Calabrian Arc (Southern Italy). Journal of Geodynamics, 43(3):393-414. https://doi.org/10.1016/j.jog.2006.10.006 doi:  10.1016/j.jog.2006.10.006
    Terranova, O. G., Gariano, S. L., 2014. Rainstorms Able to Induce Flash Floods in a Mediterranean-Climate Region (Calabria, Southern Italy). Natural Hazards and Earth System Sciences, 14(9):2423-2434. https://doi.org/10.5194/nhess-14-2423-2014 doi:  10.5194/nhess-14-2423-2014
    Tortorici, G., Bianca, M., de Guidi, G., et al., 2003. Fault Activity and Marine Terracing in the Capo Vaticano Area (Southern Calabria) during the Middle-Late Quaternary. Quaternary International, 101-102:269-278. https://doi.org/10.1016/s1040-6182(02)00107-6 doi:  10.1016/s1040-6182(02)00107-6
    Tortorici, L., 1982. Lineamenti Geologico-Strutturali Dell'arco Calabro-Peloritano. Rend. Soc. Geol. It. Miner. Petrol., 38(3):927-940 (in Italian)
    Tortorici, L., Monaco, C., Tansi, C., et al., 1995. Recent and Active Tectonics in the Calabrian Arc (Southern Italy). Tectonophysics, 243(1/2):37-55. https://doi.org/10.1016/0040-1951(94)00190-k doi:  10.1016/0040-1951(94)00190-k
    Vai, G. B., 1992. Il Segmento Calabro-Peloritano Dell'orogene Ercinico. Disaggregazione Palinspastica. Boll. Soc. Geol. Ital., 111:109-129 (in Italian)
    van Westen, C. J., Castellanos, E., Kuriakose, S. L., 2008. Spatial Data for Landslide Susceptibility, Hazard, and Vulnerability Assessment:An Overview. Engineering Geology, 102(3/4):112-131. https://doi.org/10.1016/j.enggeo.2008.03.010 doi:  10.1016/j.enggeo.2008.03.010
    Vennari, C., Gariano, S. L., Antronico, L., et al., 2014. Rainfall Thresholds for Shallow Landslide Occurrence in Calabria, Southern Italy. Natural Hazards and Earth System Sciences, 14(2):317-330. https://doi.org/10.5194/nhess-14-317-2014 doi:  10.5194/nhess-14-317-2014
    Versace, P., Ferrari, E., Gabriele, S., et al., 1989. Valutazione Delle Piene in Calabria. C.N.R.-I.R.P.I. Geodata, 30: 232
    Wasowski, J., del Gaudio, V., Pierri, P., et al., 2002. Factors Controlling Seismic Susceptibility of the Sele Valley Slopes:The Case of the 1980 Irpinia Earthquake Reexamined. Surv. Geophys., 23:563-593 doi:  10.1023/A:1021230928587
    Westaway, R., 1993. Quaternary Uplift of Southern Italy. Journal of Geophysical Research:Solid Earth, 98(B12):21741-21772. https://doi.org/10.1029/93jb01566 doi:  10.1029/93jb01566
    Willgoose, G., Hancock, G., 1998. Revisiting the Hypsometric Curve as an Indicator of Form and Process in Transport-Limited Catchment. Earth Surface Processes and Landforms, 23(7):611-623. https://doi.org/10.1002/(sici)1096-9837(199807)23:7<611::aid-esp872>3.0.co; 2-y doi:  10.1002/(sici)1096-9837(199807)23:7<611::aid-esp872>3.0.co;2-y
    Wilson, J. P., Gallant, J. C., 2000. Terrain Analysis Principles and Applications. Wiley, Toronto. 479
  • 加载中
通讯作者: 陈斌, bchen63@163.com
  • 1. 

    沈阳化工大学材料科学与工程学院 沈阳 110142

  1. 本站搜索
  2. 百度学术搜索
  3. 万方数据库搜索
  4. CNKI搜索

Figures(11)  / Tables(3)

Article Metrics

Article views(83) PDF downloads(6) Cited by()

Related
Proportional views

Influence of Tectonics and Morphometric Features on the Landslide Distribution: A Case Study from the Mesima Basin (Calabria, South Italy)

doi: 10.1007/s12583-019-1231-z
    Corresponding author: Fabio Ietto

Abstract: Identifying the instability areas provides useful information about the recognition of the vulnerable zones and,thus,helps to potentially decrease the harm to the infrastructure and the hazard conditions in inhabited areas. In this regard,morphometric parameters and tectonic setting are widely employed in mapping,modelling and understanding of instability processes. The present study is aimed to analyse the combined effects of slope morphometry (slope gradient,slope curvature,local relief),of lithology,of drainage density and of tectonic setting on the distribution of landslides. The study area is located in the Mesima Basin that lies in the central part of the Calabria region (southern Italy). The morphometric analysis was carried out by geographic information system (GIS) techniques,whereas the geomorphic attributes were computed by a digital elevation model (DEM). The recognized landslides and faults were digitized and stored in a GIS geo-database that allowed the construction of relative density maps. A total of 1 991 landslides and 231 tectonic lineaments were recognized and mapped. The distribution of the collected data suggests that the occurrence of landslides is not random. Indeed,the research highlights as the lithology,the fault density,the slope gradient and the local relief play an important role in determining the landslide occurrence. The used approach is aimed to reinforce the knowledge about the validity of the application of morphometric analysis to the landslide susceptibility. The Mesima Basin is a poorly studied area of the Calabria from a geomorphological viewpoint. Indeed,previous researches focused mainly on geological and on tectonic aspects,as well as on instability phenomena in the Mesima surroundings. Thus,this paper takes a step forward with respect to previous studies because it augments the knowledge about the relationship between faults,morphometric features and the occurrence of landslide.

Massimo Conforti, Fabio Ietto. Influence of Tectonics and Morphometric Features on the Landslide Distribution: A Case Study from the Mesima Basin (Calabria, South Italy). Journal of Earth Science, 2020, 31(2): 393-409. doi: 10.1007/s12583-019-1231-z
Citation: Massimo Conforti, Fabio Ietto. Influence of Tectonics and Morphometric Features on the Landslide Distribution: A Case Study from the Mesima Basin (Calabria, South Italy). Journal of Earth Science, 2020, 31(2): 393-409. doi: 10.1007/s12583-019-1231-z
  • The Mesima Basin is located in the south-western sector of the Calabria region (southern Italy) and flows into the Tyrrhenian Sea (Fig. 1). The basin extends on a surface of 806.41 km2, spanning from 42°84′981″N to 42°43′059″N of latitude and from 58°00′99″E to 61°59′26″E of longitude. The elevation of the area ranges between 0 and 1 265 m.a.s.l., with an average value of 403 m.a.s.l..

    The rainfall values in the Mesima Basin range between 840 and 2 080 mm/year, proceeding from the coast towards the internal mountainous area, with an average value equal to 1 100 mm/year (Versace et al., 1989). Cyclones, influenced by the west-wind-zone, bring heavy rainfalls in autumn and winter, with sporadic phenomena in spring. Thus, between October and March the short and heavy rainfalls may be frequent reaching abundant or extreme values, which may trigger landslides and severe water erosion processes (Antronico et al., 2017; Ietto et al., 2015; Terranova and Gariano, 2014; Vennari et al., 2014).

  • The Calabria-Peloritani Arc (CPA), in southern Italy, is a prominent arc-shaped structure of the Mediterranean orogenic belt. This structure represents the maximum deformation of the Apennine–Maghrebian chain, correlated with a chain-foredeep-foreland system because of the convergence of the Africa-Europe plates (Pellegrino and Prestininzi, 2007; Vai, 1992; Tortorici, 1982; Amodio-Morelli et al., 1976). The overall architecture of the CPA is made up of a series of crystalline basement nappes, some of them covered by Meso–Cenozoic sediments. The tectonic evolution of the CPA is mainly related to a trend with a prevalent compressional movement. The latter is linked to the subduction process involving the African paleomargin (Tortorici et al., 1995; Vai, 1992; Dewey et al., 1989; Bonardi et al., 1982). Thrusting, occurring since the Miocene age, has been associated with a regional strike-slip tectonic regime, whilst in the Late Pliocene–Early Quaternary an extensional phase caused the fragmentation of the arc. Quaternary fault systems are represented by NE-SW, N-S and E-W trending extensional lineaments that develop, more or less continuously, along the inner side of the arc (Tansi et al., 2007; Monaco and Tortorici, 2000; Tortorici et al., 1995; Westaway, 1993; Fabbri et al., 1980; Ghisetti, 1980). The normal transfer fault systems were the consequence of a relevant tectonic uplift that is still active (Miyauchi et al., 1994; Ghisetti and Vezzani, 1982). In Capo Vaticano area (Fig. 1), the rates of uplift were estimated equal to ∼1 mm/year if averaged since the Middle Pleistocene and up to 2 mm/year if averaged to the Holocene (Antonioli et al., 2009, 2006; Westaway, 1993; Ghisetti, 1981). The extent of the uplift progressively decreases towards the Mesima Basin, from West to East (Ietto et al., 2015). This process created on the Tyrrhenian border of the Capo Vaticano a succession of normal transfer faults directed in the first-third and second-fourth quadrant (Fig. 2). The neotectonic framework make the Calabria one of the most seismically active sectors of the Italian peninsula, where several historical earthquakes occurred with magnitudes between 6 and 7.4 (Cucci and Tertulliani, 2006; Boschi et al., 1995). Direct effect of the strong regional uplift was also the formation of reliefs with high erosive energy, carved by steep and short watercourses with steep riverbed (Ietto and Perri, 2015).

    Figure 2.  (a) Lithostructural map of the Mesima Basin; (b) rose diagram of the fault directions detected in the Mesima Basin.

  • The main river course flowing in the central part of the Calabria is the Mesima River. The lithology of the Mesima drainage area is mainly made up of Plio-Pleistocenic deposits that unconformably lie over the Paleozoic plutonic rocks or over the Miocenic sedimentary succession (Fig. 2). In particular, the upper sedimentary sequence is constituted, from the bottom to the top, by silty clays deposits of batial environment followed by sandwave deposits alternating with sandy turbidite (Pliocene). These deposits locally pass upward to a Pleistocenic conglomerate. The lower deposits are represented by evaporitic limestones (Miocene) that overlap, in discontinuity, to the crystalline basement. The latter is constituted by gneiss and granite rock masses (Paleozoic) that undergone severe weathering processes (Ietto et al., 2017, 2016, 2015; Perri et al., 2016). Quaternary deposits, composed of eluvial-colluvial or alluvial layers (Holocene), unconformably cover the sedimentary marine sequence or, directly, the crystalline rocks.

  • The landscape of the study area is strongly controlled by the tectonic structures and by the variety of outcropping lithologies, as well as by the intense uplift process (Ferranti et al., 2006; Tortorici et al., 2003; Westaway, 1993). Indeed, in the studied area, the high tectonic activity gave rise to morphostructural landforms mainly represented by the Serre Massif and Capo Vaticano Promontory. These morphostructures are bounded by fault scarps with trends NE-SW and WNW-ESE, dipping towards the Mesima Basin (Fig. 1). Minor morphotectonic structures (e.g., straight channels, saddles and straight ridges) are aligned along other structural patterns oriented in N-S and E-W directions.

    Plateaus dominate the top slopes of the Serre Massif as well as of the Capo Vaticano Promontory. These plain morphologies are bounded by steep slopes strongly dissected by deep and narrow valleys marked by instability phenomena (Antronico et al., 2017; Ietto et al., 2017, 2016; Calcaterra and Parise, 2005). Peneplanation areas are also present and linked to the strong uplift process as the result of continental erosion surfaces of the crystalline basement rocks (Ietto et al., 2016; Tortorici et al., 2003). Furthermore, the gently rolling topography of the summit plateaus favours the development of great thickness of regolith, which correlates to intense weathering processes that affect deeply the crystalline bedrock (Ietto et al., 2017, 2007; Perri et al., 2016; Borrelli et al., 2012). Corestones and boulders of highly weathered rock are also present as the result of spheroidal weathering with subsequent removal from the original place and immersion in a sandy-textured regolith (Ietto et al., 2017, 2016; Calcaterra and Parise, 2005).

    The Mesima Basin extends mainly along a NE-SW direction, following the western border fault of the Serre Massif, and it separates the last one from Capo Vaticano promontory (Fig. 1). The basin is characterized by rounded hilly morphology, with elevations rarely higher than 500 m.a.s.l., where soft sediments outcrop. In the areas where harder rocks are dominant the landforms are more rugged and the valleys are deeper and narrow. Several orders of fluvial terraces can be observed along the valleys of the Mesima Basin and, locally, they represent the remnant of dissected alluvial fans. The terraced surfaces morphologies testify the aggradation and dissection phases of valley floor because of climatic changes and Quaternary tectonics activity (Antonioli et al., 2006; Ferranti et al., 2006). The valley bottoms become wide and flat only near the mouths of the main tributaries of the Mesima River and along the alluvial and coastal plain.

    In the study area the denudation processes are mainly represented by fluvial processes, slope wash processes and landslides. These processes are frequently triggered during heavy and prolonged rainfall causing considerable damage to inhabited areas (Conforti and Ietto, 2019; Antronico et al., 2017; Ietto et al., 2017, 2015; Ietto and Perri, 2015; Calcaterra and Parise, 2005). Indeed, flash-flood events periodically occur, often making heavy damage in the urbanized littoral areas (Antronico et al., 2017; Ietto and Perri, 2015; Calcaterra and Parise, 2000).

  • The methodological approach for the structural and landslide recognition was based on an integration of the available topographic, geological and geomorphological information and on data arising from air-photo interpretation (black and white aerial photos from September 1990 at 1 : 33 000 scale), orthophotos dating to July 2008 (1 : 10 000 scale) and Google Earth satellite images dated, respectively, May 2010, April 2011, July 2014, August 2015 and June 2016. In addition, field investigations were carried out from November 2017 to December 2018. The recognized tectonic lineaments and landslides were mapped at a 1 : 10 000 scale. The azimuthal analysis of the collected tectonic data, useful for the recognition of each fault system, was carried out using the GeoRose software.

    The inventory of mass movements enclose location, area, perimeter and typology. The latter was classified following the scheme proposed by Cruden and Varnes (1996). In the study area were mapped mainly recent landslides, using several geomorphological criteria based on the morphological freshness of landslides (Keaton and DeGraff, 1996), such as: presence of bare scarps or with poor vegetation cover, depletion and deposition areas well developed, irregular slope profiles, ground cracks, slope ruptures. Finally, the collected data were digitized and stored in a GIS geo-database that allowed the construction of the landslide and fault density maps. The maps were created by means kernel density algorithm with a spatial resolution of 10 m and search area of 1 km2, using Esri ArcGIS 10.1 software. The landslide density (LD) represents the percentage of landslide area occurring in each km2; while the fault density (FD) represents the total length of tectonic lineaments affecting each km2 (Table 1).

    Parameters Formula Unit
    Landslide density (LD) LD=(La/A)×100 (%)
    Fault density (FD) FD=Fl/A (km-1)
    Local relief (LR) LR=hmaxhmin (m)
    Drainage density (DD) DD=Sl/A (km-1)
    Hypsometric integral (HI) HI=(hmeanhmin)/(hmaxhmin) (-)
    La. Total area of landslides within unit area; A. unit area of 1 km2; Fl. total length of faults (km); Sl. total length of streams (km); hmax. altitude max (m); hmin. altitude min (m); hmean. altitude mean (m).

    Table 1.  Mathematical formulas of the parameters used in this study

  • The morphometric analysis, performed with GIS techniques, was used to calculate some relief features as slope gradient, plan curvature and local relief, which are considered the main parameters influencing landslides occurrence (Scotti et al., 2014; Conforti et al., 2012; Molin et al., 2012; Lee and Min, 2001; Pike and Wilson, 1971). The spatial distribution of these geomorphic attributes was elaborated by a DEM, with a spatial resolution of 5 m, using the Spatial Analyst tools of the ArcGIS software. The used DEM was downloaded from the website of the Centro Cartografico della Regione Calabria (http://geoportale.regione.calabria.it/opendata). The slope gradient and plan curvature maps were automatically derived from DEM. In particular, the plan curvature, which represents the shape of topography, is theoretically defined as the rate of change of slope gradient or aspect in a particular direction (Wilson and Gallant, 2000). The curvature value can be evaluated calculating the value of the radius of curvature of the specific direction and was obtained directly from the derivatives of a topographic surface (Wilson and Gallant, 2000). Plan curvature is described as the curvature of a contour line formed by intersecting a horizontal plane with the topographic surface. The influence of plan curvature on landslides is the control of the surface and subsurface hydrological regime of the slope. Positive (> 0) values of plan curvatures define convexity in the downslope direction, negative (< 0) values of plan curvatures characterize concavity of slope curvature in the downslope direction. Values of plan curvatures around zero indicate that the surface is flat. These three values allowed to classify the plan curvature map in three classes: convex, concave and flat, respectively.

    The map of local relief highlights the maximum difference in height for unit area (Table 1). This parameter provides an evaluation of tectonic uplift and fluvial erosive action (Aringoli et al., 2014; Molin et al., 2012; Della Seta et al., 2004). The map, computed from DEM, was produced by subtracting the maximum value of elevation from the minimum one within a moving window sized 1 km2 (Aringoli et al., 2014; Scotti et al., 2014; Molin et al., 2012; Agliardi et al., 2009).

  • The drainage network was automatically extracted from the DEM, with the support of the Hydrology tool of ArcGIS and following the methodology described by Peckham and Jordan (2007). Subsequently, the drainage lines were hierarchically ordered according to the Strahler (1964) hierarchic scheme. Because the drainage network pattern and its orientation are highly influenced by structural features of the area (Ietto and Perri, 2015; Molin et al., 2012; Capolongo et al., 2005; Della Seta et al., 2004), a statistical azimuthal analysis of stream orientations was carried out using the GeoRose software. This step allowed the assessment of tectonic characteristics on the geometries of the drainage channels. Furthermore, a map of the drainage density was constructed with the aim to observe the texture of the stream network and the degree of dissection of the drainage basin (Molin et al., 2012; Della Seta et al., 2004). The map of the drainage density, defined by the total length of stream channels per unit area (1 km2 in this study, Table 1), was obtained using the line density analysis tool in ArcGIS software (Moglen et al., 1998).

  • The spatial relationships between tectonic lineaments, morphometric parameters (slope gradient, plan curvature, local relief and drainage density) and landslide occurrence were evaluated by comparing the landslide inventory map with fault density map and each morphometric parameter showed in its specific map. The comparison process was carried out by the zonal statistic function in the ArcGIS spatial analysis toolbox. Therefore, spatial correlations between landslide density map and each selected morphometric parameter were determined using the Pearson correlation coefficient. The correlation was considered statistically significant at p < 0.01. The statistical analyses were done using the software SPSS 19.0.

  • The tectonic data were obtained integrating the existing geological information (Cucci and Tertulliani, 2006; Tortorici et al., 2003, 1995; Casmez, 1971) with the interpretation of aerial photos and field survey. The spatial pattern of the tectonic features is showed in Fig. 2a, in which the study area appears to be affected by several fault lineaments. The structural survey mapped 231 tectonic lineaments in the Mesima Basin area, mainly oriented in NE-SW and WNW-ESE directions, as showed by the rose diagram in Fig. 2b. A minor frequency of tectonic lineaments with NNE-SSW trending was identified and mapped as well. Finally, a number of minor faults were recognized with N-S and E-W directions (Fig. 2b). All these fault systems, are linked to the Quaternary tectonic extensional phase that characterize the whole Calabria region (Cucci and Tertulliani, 2006; Tortorici et al., 2003, 1995).

    The system of NE-SW trending normal faults is part of a large tectonic structure occurring in the Southern Calabria along the boundary between the uplifted Serre and Aspromonte mountain ranges and the Late Pliocene–Pleistocene basins of Mesima and Gioia Tauro (Pirrotta et al., 2016). This tensive structure played a key control on the morphostructure of the Monte Poro Plateau and of the Capo Vaticano Promontory (Ietto and Bernasconi, 2005). Furthermore, the NE-SW fault system has given rise to catastrophic historical earthquakes with epicentres within the study area, including the ones that occurred in 1 783 with magnitudes greater than 6 (Cucci and Tertulliani, 2006; Jacques et al., 2001; Boschi et al., 1995). Several authors (Bozzano et al., 2011; Keefer, 2002; Chiodo et al., 1999; Cotecchia et al., 1986) argued for a relationship between the high seismicity of the Mesima Basin area and the widespread instability phenomena triggered during the 1 783 seismic sequence.

    In the southern sector of the Mesima Basin, the boundary between the Paleozoic crystalline rocks and the Plio-Pleistocene sediments is marked by WNW-ESE tectonic lineaments (Fig. 2). This fault system mainly dips toward SW.

    The NE-SW and WNW-ESE extensive tectonic systems affect the morphology of the study area, which is arranged at steps on right and on left sides of the Mesima Graben. Both fault systems produce well-developed ridges and fault escarpments, with triangular and/or trapezoidal facets and juxtapose the Neogene–Quaternary sediments with the underlying Paleozoic crystalline basement. Furthermore, the extensive tectonic systems transversely cut and dislocate several orders of terraced surfaces towards the Mesima Valley (Tortorici et al., 2003).

    Starting from the Lower–Middle Pleistocene the extensional processes were accompanied by a strong regional uplift (Antonioli et al., 2009, 2006; Cucci and Tertulliani, 2006). Direct effects of the tectonic uplift produced high local relief with strong erosive energy, narrow and fault-aligned valleys with steep slopes and deepening of the drainage networks (Ietto et al., 2015).

    The map of fault density, constructed on the basis of the cumulative length of faults per unit area, is showed in Fig. 3a. The fault density values range from 0 to 2.7 km-1, with an average value of 0.55 km-1. Higher values of fault density (> 1.5 km/km2) were recorded along the horst structure of the Serre Massif and the Capo Vaticano Promontory, both crossed by the NE-SW fault system (Fig. 2). Lower values (< 0.25 km-1) were mainly observed along the alluvial and coastal plain, in the southernmost sector of the Mesima Basin (Fig. 3a).

    Figure 3.  (a) Fault density map; (b) slope gradient map; (c) local relief map; (d) plan curvature map.

  • The maps of the morphometric parameters concerning the slope gradient, the slope curvature and the local relief are given in the Fig. 3. The analysis of the data shows that the Mesima Basin is characterized by a significant geomorphic heterogeneity linked to the lithological and structural characteristics of the area. Mountain and hill landscapes affect about the 80% of the territory, in which the slope gradients range from 0 to 71.2 degrees, with an average value equal to 15 degrees (Fig. 3b).

    Landsurfaces falling between 0 and 5 slope gradient value account for the 24% of the total area. Such landsurfaces mainly occur in the lower part of the basin and, subordinately, in the summit part of the flat or gently-sloping highlands. Slopes falling within the 5–10 slope gradient class are also relatively diffused (18% of the total area) and are scattered in the local landscape. More than 27% of the study area displays slope gradients ranging from 10 to 20 degrees; whereas about 31% of the basin is affected by steep slopes with values of slope gradient more than 20° (Fig. 3b). The steep slopes mainly occur along the Serre Massif mountain ridge, dominated by a granitic complex (Graessner et al., 2000 and references therein), which borders the left flank of the basin. Subordinately, slope gradient with values > 30° occurs in the central sector of the basin (Fig. 3b). Usually, they form steep erosional scarps carved in the sand and sandstone deposits.

    The local relief map (Fig. 3c) provides a useful tool to show the spatial variation of the fluvial cuts in the study area. The obtained values of local relief range from 0 to 382.9 m, with an average value equal to 146 m. The highest values of local relief are achieved in the left flank of the basin (Fig. 3c), in which lies the area of maximum altitudes (Fig. 1). The lowest values were mainly observed on the floodplain and, secondly, on the gently rolling upland surfaces of the Serre Massif and Capo Vaticano Promontory (Fig. 3c). The spatial distribution of the local relief data, however, shows that high values (> 200 m) are recorded in the areas characterized by hard rocks, by steep slopes (> 20° in average) and by deep-narrow valleys. In addition, comparison analysis between the map of local relief and fault distribution highlights that the highest values of local relief are achieved in the fault-dominated landscapes.

    Concerning the morphology of the Mesima Basin landscape, the concave slopes dominate on the 35% of the entire area, whereas 21% of it is affected by slopes with a convex shape (Fig. 3d). Finally, flat curvature characterizes the remaining 44% of the basin area. Concave and planar topographies were mainly found on gentle slopes. Conversely, steep slopes are affected by a convex morphology. Valleys floor are mainly dominated by a concave shape and, subordinately, by a flat morphology. In the areas constituted by clayey lithologies, the slopes morphology is very articulated, where concave-convex shapes are dominant.

  • The upstream part of the Mesima catchment is a fluvial network made up of deep and narrow incisions, with river gradients up to 9%, excavated in bare rock. The gradient percentages decrease notably only towards the mouth, where the fluvial axes cross the Neogene and Quaternary sedimentary cover that characterize the hilly sub-basins and coastal plain. In these areas the watercourses are wide and the valleys have a floor slightly concave. The geometrical analysis of the Mesima River Basin shows a drainage network well developed with a maximum hierarchy order (Strahler, 1964) equal to 8. This value testifies that the basin has a quite complex configuration (Fig. 4a) because of a strong influence of the topography, lithology and tectonic systems. The hypsometric curve of the entire Mesima Basin, computed on the basis of Strahler's methodology (Strahler, 1964, 1952), shows a concave-convex shape (Fig. 4b). According to several authors (Scotti et al., 2014; Huang and Niemann, 2006; Hurtrez et al., 1999; Willgoose and Hancock, 1998; Pike and Wilson, 1971), this curve profile highlights a strong influence of the tectonic uplift on the geomorphic evolution, causing intense denudation processes on the slopes and a deep dissection of the drainage network (Kusre, 2013; Ciccacci et al., 1992). The hypsometric integral (HI) value of the curve (Table 1), is equal to 0.32 and shows a Monadnock stage (HI < 0.35 in Strahler, 1952).

    Figure 4.  (a) Drainage network map; (b) hypsometric curve of the Mesima River; (c) main stream parameters.

    In the study area the analysis of other quantitative geomorphic parameters proves that the total number of the fluvial axes was 6 949, the total length of the hydrographic network was about 2 656 km (Fig. 4c) and the stream frequency amount to about 8.6 km-1. According to Sreedevi et al. (2009), these values are indicative of a high rate of dissection. Overall, the drainage pattern is sub-dendritic, though in the upstream areas of the catchment an angular and locally sub-parallel pattern is very common in the first- and second-order sub-basins. This kind of pattern arise from faults and fractures affecting the high-competence rocks (Fig. 2a). A trellis-like pattern affects the hilly sub-basins, which are carved in clayey deposits. Instead, a pinnate pattern is common in the lower part of the basin that is dominated by the presence of a number of short and low-order tributaries. Further, the drainage network is less developed in the basin areas dominated by conglomerate deposits.

    The drainage density map of the Mesima River Basin displays significant variability with values ranging from 0.8 up to 8.2 km-1 (Fig. 5). The average value of drainage density is 3.3 km-1 and more than 60% of the study area shows values between 3 and 5 km-1. Drainage density values strictly depend by rock erodibility and by slope steepness (Sreedevi et al., 2009; Ciccacci et al., 1992). In the study area, high values (> 5 km-1) of drainage density were collected in the areas constituted by crystalline rocks and clayey deposits, where high values of local relief occur. Contrary, low drainage density values (< 2 km-1) were observed in the alluvial plain and in the areas dominated by conglomerate and sand deposits, which are characterized by high permeability and low values of local relief (Fig. 3d). In according to Radaideh et al. (2016), the spatial distribution of drainage density is also influenced by tectonic lineaments distribution. The comparison between drainage density and fault density (Table 2) showed a direct and meaningful relationship (r=0.48). The analysis also showed that slope gradient distribution and drainage density have a direct and significant relationship (r=0.71) (Table 2).

    Figure 5.  Drainage density map.

    LD (%) FD (km-1) SG (°) LR (m) DD (km-1)
    LD (%) 1.00 - - - -
    FD (km-1) 0.58 1.00 - - -
    SG (°) 0.87 0.56 1.00 - -
    LR (m) 0.75 0.39 0.89 1.00 -
    DD (km-1) 0.66 0.48 0.71 0.62 1.00
    Significant at p < 0.01.

    Table 2.  Pearson's correlation among landslide density (LD), fault density (FD), slope gradient (SG), local relief (LR), and drainage density (DD) analysed in the study area

    The fluvial organization is strongly influenced by the structural-geological characters of the study area. Several authors (Ietto et al., 2015; Capolongo et al., 2005; Mayer et al., 2003; Tortorici et al., 2003) asserted that the fluvial axes disposed perpendicular to the axis of the mountain ranges and parallel to fault alignments indicate an evolution of the drainage network controlled primarily by local tectonics and subsequently by regional Quaternary uplift. In the Mesima Basin many geomorphological anomalies, indicating fault activity and tectonic disturbance, were observed (Fig. 4a). Indeed, many fluvial channels run parallel to the direction of the tectonic lineaments and of the main geological structures. Deflected branches, alignment of deflections and variance among river branches were observed in the drainage network as well. Finally, fluvial axes lying along the fault lines are entrenched and show meander-shape. For these reasons, the influence of tectonics on drainage network was investigated through the azimuthal comparison between streams and faults. The rose diagrams in Fig. 6 show the drainage preferential trends from first to eighth hierarchic orders, as following: NE-SW trend is present on all the orders; WNW-ESE trend mainly affected the streams from third to fifth order; NNE-SSW trend is present mostly on the main streams (6th, 7th, 8th order) and, secondly, in the first and second order; N-S trend mostly influences the first and the second order; finally, the E-W fault direction mainly controls the streams belonging to the third and fourth order (Fig. 6).

    Figure 6.  Rose diagrams of the drainage trend corresponding to the recognized hierarchic orders (from 1st to 8th order).

    According to several authors (Pérez-Penã et al., 2010; Ribolini and Spagnolo, 2008; Malik and Mohanty, 2007, and many others), the obtained results show that the azimuthal distribution of higher order of fluvial streams is strongly controlled by local tectonic systems, conversely, a weak control of the fault lineaments was observed on lower order of drainage network. This characteristic suggests that other factors may play a more important role on the azimuthal arrangement. Therefore, lithologies and denudation processes, like landslides and water erosion, can be relevant on the geomorphological evolution of the drainage network. Consequently, in accordance with several authors (Santangelo et al., 2013; Rapisarda, 2009), the role of denudation processes in the low degree of hierarchical organization of the drainage network is highlighted.

  • The geomorphological analysis provided information about the spatial distribution, geometry and typology of the landslides (Fig. 7a). The results point out that the study area is affected by widespread instability phenomena, which contribute significantly to control the present-day landscape evolution of the Mesima Basin. Many landslides were observed along the deeply carved fluvial valleys or close to the main tectonic lineaments. The latter, cause pre-existing weakness zones in the rock masses encouraging the groundwater drainage and the deep weathering processes, either held responsible of instability processes (Conforti and Ietto, 2019; Borrelli and Gullà, 2017; Liu et al., 2007; Parise et al., 1997; Sorriso-Valvo et al., 1996; Dramis and Sorriso-Valvo, 1994).

    Figure 7.  (a) Landslide inventory map; (b) landslide density map.

    The geomorphological survey allowed to map (Fig. 7a) a total of 1 991 landslides (Table 3). The cumulative area affected by all mapped landslides is 63.3 km2, which constitute the 7.9% of the whole study area, with a landslide frequency roughly equal to 2.5 landslide/km2. The size of landslide body ranges from 25.1 m2 to 757 312.8 m2, with an average value of 27 798.8 m2 (Fig. 8a). In particular, Fig. 8b shows that landslide sizes greater than 10 000 m2 are the 50% of the total number of instability phenomena and only 5% exceeds 100 000 m2. The analysis of cumulative area-frequency distribution of the landslides shows that the frequency decreases for the instability phenomena with size less than 200 m2 (Fig. 8b). This result suggest that the smaller landslides are underestimated in our landslide inventory system, because of the low image resolution used for mapping mass movements (Malamud et al., 2004; Stark and Hovius, 2001).

    Landslide type N (-) Landslide size (km2) Total landslide area (%)
    Min Max Mean
    Fall 37 25.1 65.5×103 17.5 ×103 0.6 1.0
    Slide 1 351 63.7 631.1×103 32.8 ×103 44.3 70.1
    Flow 341 56.5 228.0×103 20.3 ×103 6.9 10.9
    Complex 262 107.3 397.1×103 43.4 ×103 11.4 18.0
    Total 1 991 25.1 631.1×103 27.8 ×103 63.2 100

    Table 3.  Distribution of type, number and area of landslides for the landslide inventory of the Mesima River Basin

    Figure 8.  (a) Box plot of the landslide area distribution: the lower and upper limits of each box are the 25th and 75th percentiles, the whiskers show the data range, the vertical line in the box represent the median value; (b)frequency-area distribution of the landslide inventory.

    The recognized landslides include shallow (depth < 2 m) and deep-seated (depth > 2 m) failures. The deep-seated failures involve the cover materials and/or the bedrock; whereas most of the shallow landslides are triggered in the cover materials of soil or surficial weathered bedrock. Some shallow landslides are also represented by a partial reactivation of pre-existing deep landslides.

    According to the Cruden and Varnes (1996) classification scheme, the types of landslide were classified into slide, flow, and complex (Table 3 and Fig. 9). Slide-type landslides, mainly constituted by rotational slides, are the most frequent kind of instability because they represent more of the 66.4% of the mapped landslides (Table 3). Flow-type landslides, constitute about 12.5% of the checked unstable phenomena; whereas 18.3% is the percentage reaches for the complex movements. The complex landslides, consisting of multiple types of landslide, are mainly formed by slide that evolve in flow-type. The fall-type of landslide is very rare and often un-mappable because of its relatively small dimensions. This kind of instability represents only the 2.8% of the mapped landslides and mainly occurs along steep scarps cut in granitic or gneissic rocks and on sandstone deposits, which overlie the highly erodible clayey deposits.

    Figure 9.  Examples of landslide typologies affecting study area: (a) rock-fall; (b) rock-slide; (c) earth-flow; (d) complex landslide (slide-earth flows).

    The map of landslide density portrays the sectors of the study area characterized by a different concentration of instability phenomena (Fig. 7b). The landslide density values ranging from 0.1% to 71%, with mean value of 10.5%. The map shows that high values (> 20%) of the landslide density are achieved on the foothills areas of the Serre Massif, on the mountain slopes of the Aspromonte Massif and along the slopes surrounding the Capo Vaticano Promontory (Fig. 7b). Very high values of landslide density (> 40%) are concentrated along strike-slip faults, where the relative tectonic uplift and the local relief values reach high rates (Ietto and Bernasconi, 2016; Ietto and Perri, 2015; Catalano et al., 2008; Tortorici et al., 2003). On the contrary, the alluvial and coastal plain and the summit part of the flat or gently-sloping highlands are characterized by very low values (< 5%) of landslide density (Fig. 7b). The landslides distribution suggests that the occurrence is not random, but lithology, tectonic setting and morphometric features, play an important role in determining the landslide disposition (Conforti and Ietto, 2019; Roda-Boluda et al., 2018; Borrelli et al., 2014). Indeed, the comparison between the landslide and lithology maps shows that the highest landslide concentration occurs in the silty clay deposits and in the granitic rocks highly tectonized and weathered. In these areas, it was recognized and mapped more than 62% of the total number of landslides (Fig. 10a). Instead, the 17% of mass movements affect slopes carved in the sand and sandstone deposits (Fig. 10a).

    Figure 10.  Areal distribution of landslides compared to (a) lithology (in which 1. alluvial deposit, 2. eluvial/colluvial deposit, 3. silty clays, 4. conglomerates and sands, 5. sand and sandstones, 6. evaporitic limestones, 7. gneiss, 8. granite); (b) plan curvature.

    The landslide index, expressed as the ratio in percentage between the landslide area and the area of each lithology class in the Mesima Basin, shows values equal to 12.9%, 12.4%, and 10.9% for gneissic rocks, silty clay deposits and eluvial/colluvial deposits respectively (Fig. 10a). Lowest values of landslide index were obtained for conglomeratic and sandy deposits (2.2%) and alluvial materials (0.6%). Finally, field observations demonstrated that eluvial/colluvial deposits, which often cover the igneous and metamorphic basement rock, are mainly involved by shallow landslides (such as earth flow), in agreement with several researches in similar contexts (Conforti and Ietto, 2019; Ietto et al., 2017; Calcaterra and Parise, 2005).

  • The fault density map and the maps regarding the investigated morphometric parameters (slope gradient, plan curvature, local relief and drainage density) were compared with the landslide inventory map (Figs. 10b, 11). The comparisons suggest that the landslide distribution is strongly influenced by local variations of the observed geo-morphometric features. In particular, the comparison between landslide inventory and fault density maps shows that the landslide frequency increases with the growth of fault density (Fig. 11a). The finding shows that more than 50% of the mapped landslides fall in the areas with fault density > 1 km-1. Indeed, several landslide scarps are aligned with the major fault lineaments. Therefore, many landslides are closely related to the local tectonic setting, in agreement with several authors (Conforti and Ietto, 2019; Borrelli and Gullà, 2017; Conforti et al., 2015; Calcaterra and Parise, 2010; Parise et al., 1997; Sorriso-Valvo et al., 1996; Dramis and Sorriso-Valvo, 1994) that claim the role of the faults as responsible for intense fracturing and deformation of the rocks, steep slopes and fluvial undercutting of the slope. In addition, the comparison between landslide and fault density maps shows a positive significant correlation (r=0.58, Table 2). This result testifies that the landslide occurrence increases with the increasing of the fault density. Indeed, in the basin areas constituted by weathered granitic rocks the value of fault density is greater and a higher landslide density occurs (Fig. 7b).

    Figure 11.  Relative and cumulative frequency distribution of landslides compared to: (a) fault density, (b) slope gradient, (c) local relief and (d) drainage density. Box-plots showing distribution of landslides with respect to fault density and morphometric parameters. The lower and upper limits of each box are the 25th and 75th percentiles, the whiskers show the data range, the horizontal line in each box represents the median and the black point represents the mean values.

    Slope gradient carries out a significant influence on landslide occurrence: all things being equal, steeper slopes are more inclined to failure than gentler slopes. Figure 11b shows the relationship between the slope gradient and the distribution of mass movements. The comparison suggests that the landslides frequency reaches high values on the steep topographies. Indeed, more than 85% of landslides trigger on slopes with gradients more than 20°, which characterize only the 31% of the study area. These results infer that slope gradient plays a key role on the control of landslide occurrence (Fig. 11b). Similar results were reported by Conforti and Ietto (2018), Khazai and Sitar (2003) and Wasowski et al. (2002). In addition, the same comparison between slope gradient and landslide occurrence shows that the last one increases up to a slope gradient value of 45°. If this value is exceeded, landslide occurrence generally decreases. However, the frequency of the steeper slope gradient (over 45°) is underrepresented. Fewer instability phenomena occur with the increasing of steepness (Fig. 11b), because the more weathered layers are thinner or absent along the steep slopes (Ietto et al., 2017). A strong spatial correlation was found between landslide density and slope gradient (r=0.87, Table 2). Indeed, the slope angle is the main parameter of the slope stability, because an increase of shear stress occurs with a progressive rise of the slope gradient (Saha et al., 2002).

    The comparison between the local relief map and the landslide inventory map shows that more than 80% of the landslides occur in the areas characterized by high values of local relief (> 160 m) (Fig. 11c). The highest landslide concentration was found along slopes with values of local relief between 190 and 240 m. Relatively few landslides (less than 4%) were identified in the areas with moderate or low local relief values (< 100 m) (Fig. 11c), because of the gentle morphologies of the area. Further, the same comparison of maps shows a significant positive Pearson correlation (Table 2).

    The analysis of the plan curvature shows a fairly homogeneous distribution of landslides on concave and on flat slopes, with a slight predominance of the first ones (Fig. 10b). The landslides occurrence in the convex slopes is represented by only the 7.3% of the total landslides mapped. The Fig. 10b shows that the landslide index is equal to 7.5% for concave slopes, 6.1% for flat slopes and 2.1% for areas with convex morphology. On concave slopes the dominant types of landslide are mainly complex- and flow-type; whereas on convex slopes the slide-type mass movements are prevalent. In addition, on convex morphologies, characterized by steep slopes, rare phenomena of rock-fall occur as well.

    The comparison between landslide occurrence and drainage density is shown in Fig. 11d. The latter, points out that landslide phenomena increase with the growth of the drainage density up to a value of 5 km-1. If this value is exceeded, the landslide occurrence gradually diminishes. The highest value of the landslide frequency is achieved within areas with a drainage density of 4 km-1. With regards to cumulative landslide (Fig. 11d), the analysis highlight that about 65% of landslides occur in areas with drainage density values between 3 and 6 km-1. Finally, the correlation analysis between drainage density and landslide density shows a good relationship (r=0.66) (Table 2). This sharp relationship could be linked to the geomorphologic modification of the area mainly caused by gully erosion and fluvial undercutting, as well as by water saturation of the shallower horizon. These phenomena are able to influence the triggering landslides (Ietto et al., 2017; Conforti et al., 2016; Vennari et al., 2014; Sanchez et al., 2010).

    Previous researches regarding relationship between the morphometric features and landslides are very rare in Calabria. For example, Carrara et al. (1977) argued about the comparison of some morphometric attributes of landslides occurring in the Crati and Ferro basins (North Calabria); they declared a sharp relationship between the slope instability and the lithologies outcropping in either basin areas. Other researches carried out in Daunia region (Apulian Apennines, Central Italy) by Mancini et al. (2010) found out that land cover, lithology and slope exposure are strongly related to the occurrences of slope failure. Similar results were obtained by several authors in worldwide researches, such as: in Japan by Oguchi (1997), in France by Ribolini and Spagnolo (2008), in Spain by Pérez-Peña et al. (2010), in Romania by Petrea et al. (2014) and in India by Malik and Mohanty (2007). All these researchers affirmed that the analysis of morphometric features constitutes a key factor for determining the probability of landslide occurrence in an area.

  • More knowledge about the processes that lead to instability phenomena provides fundamental information about the evolution of landscapes. The main goals of this study were achieved in two phases. The first one: to analyse, evaluate and compare the effects of the tectonic setting on landscape evolution. The second one: to understand the influence of the tectonic systems and morphometric features on the distribution of landslides in the Mesima River Basin (Calabria, southern Italy).

    Strong rates of tectonic uplift affected the Calabria and gave rise to the current complex morphology. The strong uplift stage was accompanied by extensional processes represented by NE-SW and WNW-ESE directed normal faults. These tectonic lineaments conditioned the river network pattern and the morphostructural ridges. Other minor tectonic structures affected the landscape modelling in very localized areas. A total of 231 tectonic lineaments were recognized and mapped in the Mesima Basin. The analysis of data confirmed the importance of the tectonic pattern in the development and evolution of the catchment drainage network. Indeed, a deeply incised river network, because of the relative changes of the river base level, was recognized within the central and higher parts of the basin. In these areas slopes steepening and geomorphic instability are very common.

    A number of 1 991 landslides were mapped in the Mesima Basin. The main typologies of the landslides that affect the slopes are rotational slides, complex slides (e.g., slide earth-flow) and flow-types. Rare rock-falls involve the straight and steep slopes dominated by more resistant rocks. The landslides area, conceived as the sum of the total mapped landslides, occupy an surface equal to 63.3 km2, which is more than 7% of the study area (806.41 km2). The observation of the occurrence, abundance and distribution pattern of the landslides showed a complex interplay with lithological features, tectonic pattern, slope morphology and drainage density. The lithology is an important factor in the spatial distribution of the landslide phenomena. Most of the landslides (65.1%) occurred on slopes carved in silty clays and crystalline rocks (granites and gneiss). The latter are pervasively affected by discontinuities, deeply weathered and characterized by a high local relief. The highest landslide index (12.9%) was observed in the gneiss rocks; granitic rock masses, however, are the lithology with the greatest number of the mass movements. A strong relationship was found between tectonic pattern and the distribution of landslides. Several landslides were recognized close to the high fault concentration areas characterized by a wide cataclastic zone producing highly fractured and weathered rocks. Indeed, the analysis of data showed that the landslide density increases with increasing of the fault density and the 73% of the landslides occur within the areas with a high fault density (0.5–2.4 km-1). The comparison between the spatial distribution of landslides and the slope morphology testified that concave and flat configuration of the slopes are the most frequently areas affected by landslides (45.1% and 47.6% of the landslide areas, respectively). Furthermore, about 70% of the mapped landslides trigger on the slopes with a steepness between 20 and 45 grade. Exceeded these slope gradient values, landslide frequency generally decreases, because the weathering of the rocks decreases or is absent along the steep slopes. Finally, an increase of instability phenomena was also observed with the increasing of drainage density, because the growth of river incisions coupled with bank erosion cause a steepening of hillslopes making the slopes unstable.

    Moreover, the relationship between landslide density, fault density, slope gradient, local relief, and drainage density were statistically evaluated. The results showed significant positive correlations among landslide density, fault density and morphometric parameters.

    The achieved results suggest that the landslide distribution and its comparison with lithological features, tectonic pattern, slope morphology and drainage density provide valuable information for the study of morphodynamic evolution. In particular, the results supply useful information about the understanding of the landscape evolution processes in a poorly studied area of the Calabria. They provide a useful knowledge for the implementation of effective methods for the assessment, prediction and reduction of the landslide hazard. In general, the approach used in this research could provide a model of guidance for an assessment of landslide susceptibility in other Mediterranean areas characterized by similar morphodynamic processes.

  • This work was supported by the MIUR-ex 60% Project (Responsibility of Fabio Ietto). The authors wish to thank the two anonymous Reviewers for their critical comments and suggestions, which greatly improved the quality of the manuscript. The final publication is available at Springer via https://doi.org/10.1007/s12583-019-1231-z.

Reference (117)

Catalog

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return