Environmental Hazards and Society: Landsliding in Basilicata, Italy, with Specific Reference to Grassano
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1 Environmental Hazards and Society: Landsliding in Basilicata, Italy, with Specific Reference to Grassano by Stuart Oliver A dissertation submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy at the The London School of Economics and Political Science May 1993 UMI Number: U091966 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. Dissertation Publishing UMI U091966 Published by ProQuest LLC 2014. Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 POLITICAL \ JL> oo O oo N) CA 2 A b s tra c t This dissertation takes a realist approach to examine landsliding in the Basilicata region of Italy, with specific reference to the municipality of Grassano, in order to understand humankind’s role in contributing to environmental hazards. It concludes that environmental hazards such as landslides have partiy-social causes, which are characteristic of the societies they affect, and any real accommodation with environmental hazards must involve radical social change. The dissertation analyzes the differing explanations for environmental hazards given by previous schools of thought. Passing to the empirical material to be examined using these ideas, it describes the current pattern of landslides in Basilicata and discusses whether the reported landslide hazard has increased during the twentieth century. It then examines the physical environment of the region, and discusses the extent to which recent reported changes in the intensity of landslides are correlated to changes in the use of the land. The example of the municipality of Grassano allows an examination of the causative mechanisms behind the regional trends. The dissertation examines the vulnerability of Grassano’s physical environment to landslides, and the social factors which have influenced landsliding there. It then discusses the history of landslides in the municipality, and the extent to which they have intensified during the twentieth century. Finally it questions the degree to which reported changes in the level of landslides in Grassano have been the result of a growing sensitivity to landslides. The dissertation’s conclusion summarizes the work done, then evaluates the contribution to academic knowledge. It ends with an assessment of the viability of likely future approaches to reducing the landslide hazard in Basilicata. 3 / C ontents The text 8 P re fa c e 9 Acknowledgements 10 Qbhapter 1: Introduction 1 1 1.1 Introduction 1 1 1.2 Definition of the research problem 1 1 1.2.1 Humankind and the environment 1 1 1.2.2 Environmental hazards 1 1 1.2.3 Mass movement and landslides 1 3 1.2.4 The case-study area 1 5 1.3 The research’s ontology, epistemology, and methodology 1 7 1.4 Overview of the research 2 1 Chapter 2: Environmental hazards 2 4 2.1 Introduction 2 4 Q 2.2 Approaches to the environment 2 5 ^ 2 . 3 Hazards 2 6 2.3.1 Approaches to hazards 2 7 2.3.2 Behaviouralist research on environmental hazards 2 8 2.3.3 Structuralist research on environmental hazards 3 1 2.4 Landslides as an example of an environmental hazard 3 6 2.4.1 Introduction 3 6 2.4.2 The approaches to landslides 4 2 2.4.3 Landslides in the Mediterranean 4 4 2.5 Conclusions 5 1 Chapter 3: Landslides in Basilicata 5 3 3.1 The current pattern of landslides 5 3 3.2 Historical trends in landsliding 6 3 3.3 Conclusions 7 6 4 Chapter 4: The reasons for landslides in Basilicata 7 8 4.1 Introduction 7 8 4.2 The physical factors 7 9 4.2.1 Introduction 7 9 4.2.2 Relief 8 0 4.2.3 Geology 8 3 4.2.4 Tectonism and seismicity 8 7 4.2.5 Climate 8 8 4.2.6 Vegetation 9 2 4.2.7 Conclusions 9 6 4.3 The social factors 9 7 4.3.1 Indirect impacts on the land 9 7 4.3.1.1 Introduction 9 7 4.3.1.2 Deforestation 9 9 4.3.1.3 Agriculture 102 4.3.1.4 Urbanization 111 4.3.1.5 Industrialization 114 4.3.2 Direct impacts on the land 1 1 4 4.4 Conclusions 1 2 3 Chapter 5: Landslides at Grassano 125 5.1 Introduction 1 2 5 5.1.1 The landslides 1 2 5 5.1.1.1 The urban landslides 1 2 5 5.1.1.2 The town-centre paleoslide 1 2 7 5.1.1.3 Other landslides 1 3 7 5.2 The physical factors 1 3 8 5.3 The social factors 1 4 6 5.3.1 Deforestation 1 4 6 5.3.2 Agriculture 147 5.3.3 Construction 1 5 6 5.3.4 Land management 1 58 5.4 Conclusions 1 58 Chapter 6: The history of landslides at Grassano 161 6.1 Introduction 161 6.2 Environmental change before the twentieth century 161 5 6.3 Landslides in the twentieth century 1 6 5 6.3.1 Landslides from 1900 until the 1930s 1 6 7 6.3.1.1 The 1902 Cinti landslides 1 6 7 6.3.1.2 The 1903 Via San Sofia landslide 1 6 8 6.3.1.3 The 1907 landslide 1 6 8 6.3.1.4 Later landslides, 1907 to 1930 1 69 6.3.2 Other minor landslides 1 7 0 6.3.3 Urban landslides 171 6.3.3.1 The Cinti landslide 171 6.3.3.2 The Via Capolegrotte landslide 1 7 2 6.3.3.3 The Petrino landslides 17 2 6.3.3.4 Other landslides 1 7 3 6.3.4 The Calvario landslide 17 3 6.3.5 The cemetery landslide 181 6.4 Conclusions 1 8 5 Chapter 7: Managing landslides at Grassano 187 7.1 Introduction 1 8 7 7.2 The response to landslides 1 8 7 7.3 The management of hazards 1 9 0 7.3.1 The political response 1 9 0 7.3.2 Local people 1 9 3 7.3.3 Politics and research 2 0 3 7.3.4 The cemetery problem 2 08 7.4 Conclusions 21 3 Chapter 8: Summary and conclusions 215 8.1 Introduction 2 1 5 8.2 Summary of work done 2 1 5 8.3 Evaluation of work done and statement of limitations 2 20 8.3.1 The work done and its limitations 2 20 8.3.2 Further research 2 22 8.4 Contribution to knowledge 2 23 8.5 Discussion of significance of the findings and their application 2 2 6 Appendix A: The landslide-inventory maps 2 29 Appendix B: The regional landslide data 2 3 5 6 B.1 The historical data 2 3 5 B.2 Chi-square tests 2 3 5 B.2.1 Contingency comparisons of 1906 to 1910 2 3 6 B.2.2 Contingency comparisons of 1906 to 1986 2 3 6 B.2.3 Contingency comparisons of 1910 to 1986 2 3 7 Appendix C: Spending on landslides 2 3 9 C.1 Introduction 2 39 C.2 Urban landslides 2 41 C.3 General land reclamation projects 2 4 8 Appendix D: Geotechnical data on Grassano 254 Appendix E: The placenames of Grassano 2 57 Appendix F: Political power in Grassano 2 59 F.1 Introduction 2 5 9 F.2 Interviews with the mayors 2 6 3 F.3 Interviews with the councillors 2 6 4 Appendix G: The semi>structured interviews 2 66 Bibliography 275 Archives consulted 2 7 5 Sources 2 7 5 F ig u re s 1.1 Basilicata 1 6 3.1 Basilicata: settlements 5 4 3.2 Oliveto Lucano 5 5 3.3 Basilicata: superficial instability 5 8 3.4 Basilicata: deep instability 5 9 3.5 Basilicata: landslides 61 3.6 Basilicata: urban landslides 6 2 3.7 Basilicata: consolidation orders forurban centres 6 8 3.8 Basilicata: urban landslides in 1906 7 0 7 3.9 Basilicata: urban landslides in 1910 71 3.10 Basilicata: urban landslides in 1986 7 2 4.1 Basilicata: relief 81 4.2 Basilicata: major rivers 8 2 4.3 Basilicata: geology 8 5 4.4 Basilicata: seismicity 8 9 4.5 Basilicata: precipitation 91 4.6 Basilicata: landuse 9 3 4.7 Italy: population 1 0 4 4.8 Basilicata: population 1 0 5 4.9 Basilicata: settlement sites 1 1 2 5.1 Grassano 1 2 6 5.2 Grassano: street plan 1 2 8 5.3 Grassano: slope instability 12 9 5.4 Grassano: urban landslides 1 3 0 5.5 Grassano: drainage and relief 13 9 5.6 Grassano: lithology 1 41 5.7 Grassano: geology 14 2 5.8 Grassano: districts 1 4 5 5.9 Grassano in 1662 1 4 8 5.10 Grassano: deforestation from 1860 to 1910 1 4 9 5.11 Grassano: population 151 6.1 Grassano: the Calvario district 1 7 6 6.2 Grassano: the cemetery 1 8 2 7.1 Grassano: consolidation (1988 Lire) 1 8 9 7.2 Grassano: land plots around the site of the proposed new cemetery 2 0 9 A.1 Basilicata: outline of landslide-inventory maps 2 3 0 C.1 Italy: price inflation 2 4 0 T a b les 2.1 Factors affecting potential slope instability 38 8 3.1 Basilicata: proportion of the land affected by slope instability 5 6 3.2 Landslide-inventory maps: superficial and deep instability 6 0 3.3 Basilicata: urban landslide data 6 4 3.4 Basilicata: selected urban landslides 7 3 3.5 Basilicata: consolidation orders 7 6 4.1 Basilicata: the relationship between slope steepness and type of 8 3 slope instability 4.2 Ferro Basin: the relationship between lithology and the type of landslide 8 6 4.3 North Calabria: the relationship between lithology and the size of landslide 8 6 4.4 Basilicata: selected climatic data for 1926 to 1955 9 0 4.5 Basilicata: landuse 9 4 4.6 Basilicata: landuse and landslides 9 5 4.7 Ferro Basin: landuse and landslides 9 6 4.8 Basilicata: changes in forest tenure from 1809 to 1870 1 01 4.9 Basilicata: reforestation from 1950 to 1980 1 0 2 4.10 Southern Italy: landuse from 1861 to 1970 1 09 4.11 Ferro Basin: artefacts and slope instability 1 13 5.1 Grassano: earthquake-damaged buildings in 1857 1 3 4 5.2 Tricarico: climatic data for 1926 to 1955 1 4 3 5.3 Tricarico: weather details 1 4 4 5.4 Grassano: proportion of land cultivated from 1929 to 1970 1 5 5 5.5 Grassano: landuse from 1814 to 1942 1 5 6 7.1 Grassano: spending at 1988 prices on urban landslides from 1 9 0 the 1840s to the 1980s The text The dissertation’s text follows the general prescriptions set out in Maney and Smallwood (1981), with spelling conventions following Fowler (1965).