Processes, mechanisms and parameters significant to instability have been identified from an investigation which has included 1) Geomorphological mapping and appraisal. 2) Field Monitoring. 3) Quantitative assessement of rock mass geometry, mineralogy, engineering properties and physical/physico-chemical behaviour. The north coast of the Bristol Channel is exposed to severe marine attack. Weak lithologies are exploited and the cliffs undermined. Principal failure modes recognised were toppling and vertical translation. Thermal gravimetry indicated allotropy of sulphide minerals. The least stable forms were identified in the more calcareous mudrocks, and a laboratory leaching experiment demonstrated that weatherability was greatest in such mudrocks. Pyrite oxidation was shown not only to enhance carbonate leaching, but to degrade the clay minerals and induce rehydration of the double layer. Uniaxial compressive strengths of representative mudrocks were determined for a range of moisture contents. Mean values varied between 5 and 64 MPa. An investigation into deformation anisotropy of a clay shale is also recorded. Meso and micro scale carbonate filled discontinuities are apparent in the limestones. Hoek & Brown's criterion was used to characterise results of a programme of strength testing. Average uniaxial compressive strength of the intact limestone was 234 MPa. In the field, many major discontinuities were identified as tensile in origin. Results from shear tests along limestone tension fractures could not be adequately represented by Barton's equation. A power relationship between shear strength and normal stress gave good correlation. Leaching, moisture and temperature movements, freeze-thaw and pressure release all act to impair stability. Extreme weather was shown to trigger failure. Limiting equilibrium analyses of toppling showed that torsional shear strength mobilized along the failure surface in the plane of toppling contributed significantly to forces resisting toppling. Both local masonry protection and pre-split blasting are recommended as viable expedients in protection and stabilization works.

LEITE, Nicolly Santos. Zoneamento paisagístico das falésias do litoral de Fortim/Ceará: subsídios ao planejamento e à gestão ambiental. 2016. 180 f. Dissertação (Mestrado em geografia)- Universidade Federal do Ceará, Fortaleza-CE, 2016. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-07-28T19:05:04Z No. of bitstreams: 1 2016_dis_nsleite.pdf: 8465160 bytes, checksum: 447da076a29a73429fc33d0159f0cdfb (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-08-02T14:23:31Z (GMT) No. of bitstreams: 1 2016_dis_nsleite.pdf: 8465160 bytes, checksum: 447da076a29a73429fc33d0159f0cdfb (MD5) / Made available in DSpace on 2016-08-02T14:23:31Z (GMT). No. of bitstreams: 1 2016_dis_nsleite.pdf: 8465160 bytes, checksum: 447da076a29a73429fc33d0159f0cdfb (MD5) Previous issue date: 2016 / The sea cliffs are important morphologies in the coastal landscape of Ceará, setting in steep and unstable slopes in coastal areas affected by wind, rain and especially marine flow, and its associated training mainly to the deposition of the Barreiras Group sediments. On the coast of Fortim, the sea cliffs are distributed in the coastal plain and along the left bank of the river Jaguaribe, where you can see the highest population density and concentration of infrastructure associated with the tourism. The research is inserted in the municipality of Fortim, the main spatial extent its sea cliffs coastline, compartmentalized into three sectors of study, occupying in total an area of 7.089.3 hectares (70, 89 km²), for which was held analysis of landscape dynamics in an integrated way, linking the environmental aspects of the socioeconomic conditions in order to contribute to environmental planning and management that are consistent with the reality in question. The research is headed in the analysis of the dynamics and typology of the landscape, following thus systemic assumptions from the theoretical and methodological foundations of Geoecology landscape. The research stages permeated the field research for application checklist and collection of environmental data, granulometric analysis of sediments, water analysis and cartographic products, which used RapidEye 2013 satellite images on the scales of 1: 40,000 and 1: 80,000. They were, in the stages mentioned, the sea cliffs of Fortim are formed by rocks of the Barreiras Group and in some sectors are associated with Formation Tibau rocks; generally they consist of medium sands and strongly cemented sandstones. Regarding the forms of use and occupation of coastal, activities were identified developed in Permanent Preservation Areas, such as shrimp farming in fluviomarinha plain of the river Pirangi, allotments and second homes, mainly on the tops of sea cliffs, contributing mainly to the mischaracterization of the landscape and the privatization of space. In some sectors, there is no occupation of the sea cliffs, however the small stretch of beach strip makes the vulnerable side to wave action. It was also noted, through physical, chemical and microbiological analyzes, the quality of water from community wells is committed to consumption, especially in areas of high population density. In this sense, one should promote the management of the area, being necessary to know the coastal carrying capacity with cliffs with a view to preventing and minimizing possible negative influence on natural systems and human populations that live in the surrounding areas of these environments. / As falésias são importantes morfologias no contexto paisagístico costeiro cearense, configurando-se em escarpas abruptas e instáveis nas zonas costeiras, influenciadas pelo fluxo eólico, pluvial e, principalmente, marinho, tendo sua formação associada, principalmente, à deposição dos sedimentos do Grupo Barreiras. No litoral de Fortim, as falésias estão distribuídas na planície litorânea e ao longo da margem esquerda do rio Jaguaribe, onde se pode notar maior adensamento populacional e concentração de infraestruturas associadas ao veraneio e ao turismo. A pesquisa se insere no Município de Fortim, tendo como principal abrangência espacial o seu litoral de falésias, compartimentado em três setores de estudo, que ocupam no total uma área de 7.089,3 hectares (70, 89 km²), para a qual se realizou análise da dinâmica paisagística de modo integrado, relacionando os aspectos físico-ambientais às condições socioeconômicas, a fim de contribuir para um planejamento e gestão ambiental que sejam compatíveis com a realidade em questão. A pesquisa se encaminhou na análise da dinâmica e tipologia da paisagem, seguindo, assim, pressupostos sistêmicos desde as bases teórico-metodológicas da Geoecologia da Paisagem. As etapas da pesquisa perpassaram os levantamentos de campo para aplicação de checklist e coleta de dados ambientais, análise granulométrica de sedimentos, análises de água e de produtos cartográficos, em que se utilizou imagens de satélite RapidEye 2013 nas escalas de 1:40.000 e 1:80.000. Verificou-se, nas etapas mencionadas, que as falésias de Fortim são formadas por rochas do Grupo Barreiras e em alguns setores estão associadas às rochas da Formação Tibau; em geral, são constituídas por areias médias e arenitos fortemente cimentados. Em relação às formas de uso e ocupação no litoral, foram identificadas atividades desenvolvidas em Áreas de Preservação Permanente, como a carcinicultura na planície fluviomarinha do rio Pirangi, loteamentos e segundas residências, principalmente, nos topos de falésias, que contribuem, sobretudo, para a descaracterização da paisagem e na privatização do espaço. Em alguns setores, não há ocupação nas falésias, contudo a pequena extensão da faixa de praia torna a vertente vulnerável à ação das ondas. Verificou-se, também, por meio de análises físico-químicas e microbiológicas, que a qualidade da água de poços comunitários encontra-se comprometida para consumo, principalmente nas áreas de maior adensamento populacional. Nesse sentido, deve-se promover o gerenciamento da área, sendo preciso conhecer a capacidade de suporte de litorais com falésias, com vistas a prevenir e minimizar possíveis influxos negativos aos sistemas naturais e às populações humanas que habitam o entorno desses ambientes.

Cette thèse a pour but de comprendre quels processus contrôlent l'érosion des falaises côtières à deux échelles spatiales. Nous avons d'abord réalisé une étude locale de la falaise de flysch de Socoa (Pays Basque), dont la spécificité est un fort contrôle structural. Elle a été suivie annuellement par photogrammétrie pendant 6 ans. Cette falaise résistante recule lentement, à 3,4 mm/an. Son erosion est le fait de départ de blocs, majoritairement au niveau des arêtes libres. Ensuite, afin d'aborder l'échelle globale, une base de données (GlobR2C2, Global Recession Rates of Coastal Cliffs) a été créée. Elle est la première à recenser les taux d'érosion publiés et à les comparer à des forçages météo-marins issus de grilles mondiales. Nous l'avons traitée par analyse statistique exploratoire et par random forest. La résistance de la roche parait être le premier facteur contrôlant le taux d'érosion. Au second ordre, apparaissent le nombre de jours de gel par an et le marnage. / The aim of this PhD is to understand factors controlling sea cliff erosion at both local scale, based on Socoa cliff (Basque country) and at global scale. The specificity of Socoa's flysch cliff is its strong structural control. A 6 year photogrammetric study from annual records was conducted. This resistant cliff erodes slowly at 3.4 mm/yr and rockfalls occur mostly at cliff edge. A database called GlobR2C2 (Global Recession Rates of Coastal Cliffs) was set up. It is the first one to compile erosion rate data extracted from literature and to compare it to marine and continental forcing, extracted from worldwide grids and reanalyses. It was statistically analysed through exploratory analysis and random forest. At global scale, rock resistance appears to be the primary factor controlling cliff erosion. Second orders factors are the number of frost day per year and the average tidal range.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / As falÃsias sÃo importantes morfologias no contexto paisagÃstico costeiro cearense, configurando-se em escarpas abruptas e instÃveis nas zonas costeiras, influenciadas pelo fluxo eÃlico, pluvial e, principalmente, marinho, tendo sua formaÃÃo associada, principalmente, à deposiÃÃo dos sedimentos do Grupo Barreiras. No litoral de Fortim, as falÃsias estÃo distribuÃdas na planÃcie litorÃnea e ao longo da margem esquerda do rio Jaguaribe, onde se pode notar maior adensamento populacional e concentraÃÃo de infraestruturas associadas ao veraneio e ao turismo. A pesquisa se insere no MunicÃpio de Fortim, tendo como principal abrangÃncia espacial o seu litoral de falÃsias, compartimentado em trÃs setores de estudo, que ocupam no total uma Ãrea de 7.089,3 hectares (70, 89 kmÂ), para a qual se realizou anÃlise da dinÃmica paisagÃstica de modo integrado, relacionando os aspectos fÃsico-ambientais Ãs condiÃÃes socioeconÃmicas, a fim de contribuir para um planejamento e gestÃo ambiental que sejam compatÃveis com a realidade em questÃo. A pesquisa se encaminhou na anÃlise da dinÃmica e tipologia da paisagem, seguindo, assim, pressupostos sistÃmicos desde as bases teÃrico-metodolÃgicas da Geoecologia da Paisagem. As etapas da pesquisa perpassaram os levantamentos de campo para aplicaÃÃo de checklist e coleta de dados ambientais, anÃlise granulomÃtrica de sedimentos, anÃlises de Ãgua e de produtos cartogrÃficos, em que se utilizou imagens de satÃlite RapidEye 2013 nas escalas de 1:40.000 e 1:80.000. Verificou-se, nas etapas mencionadas, que as falÃsias de Fortim sÃo formadas por rochas do Grupo Barreiras e em alguns setores estÃo associadas Ãs rochas da FormaÃÃo Tibau; em geral, sÃo constituÃdas por areias mÃdias e arenitos fortemente cimentados. Em relaÃÃo Ãs formas de uso e ocupaÃÃo no litoral, foram identificadas atividades desenvolvidas em Ãreas de PreservaÃÃo Permanente, como a carcinicultura na planÃcie fluviomarinha do rio Pirangi, loteamentos e segundas residÃncias, principalmente, nos topos de falÃsias, que contribuem, sobretudo, para a descaracterizaÃÃo da paisagem e na privatizaÃÃo do espaÃo. Em alguns setores, nÃo hà ocupaÃÃo nas falÃsias, contudo a pequena extensÃo da faixa de praia torna a vertente vulnerÃvel à aÃÃo das ondas. Verificou-se, tambÃm, por meio de anÃlises fÃsico-quÃmicas e microbiolÃgicas, que a qualidade da Ãgua de poÃos comunitÃrios encontra-se comprometida para consumo, principalmente nas Ãreas de maior adensamento populacional. Nesse sentido, deve-se promover o gerenciamento da Ãrea, sendo preciso conhecer a capacidade de suporte de litorais com falÃsias, com vistas a prevenir e minimizar possÃveis influxos negativos aos sistemas naturais e Ãs populaÃÃes humanas que habitam o entorno desses ambientes. / The sea cliffs are important morphologies in the coastal landscape of CearÃ, setting in steep and unstable slopes in coastal areas affected by wind, rain and especially marine flow, and its associated training mainly to the deposition of the Barreiras Group sediments. On the coast of Fortim, the sea cliffs are distributed in the coastal plain and along the left bank of the river Jaguaribe, where you can see the highest population density and concentration of infrastructure associated with the tourism. The research is inserted in the municipality of Fortim, the main spatial extent its sea cliffs coastline, compartmentalized into three sectors of study, occupying in total an area of 7.089.3 hectares (70, 89 kmÂ), for which was held analysis of landscape dynamics in an integrated way, linking the environmental aspects of the socioeconomic conditions in order to contribute to environmental planning and management that are consistent with the reality in question. The research is headed in the analysis of the dynamics and typology of the landscape, following thus systemic assumptions from the theoretical and methodological foundations of Geoecology landscape. The research stages permeated the field research for application checklist and collection of environmental data, granulometric analysis of sediments, water analysis and cartographic products, which used RapidEye 2013 satellite images on the scales of 1: 40,000 and 1: 80,000. They were, in the stages mentioned, the sea cliffs of Fortim are formed by rocks of the Barreiras Group and in some sectors are associated with Formation Tibau rocks; generally they consist of medium sands and strongly cemented sandstones. Regarding the forms of use and occupation of coastal, activities were identified developed in Permanent Preservation Areas, such as shrimp farming in fluviomarinha plain of the river Pirangi, allotments and second homes, mainly on the tops of sea cliffs, contributing mainly to the mischaracterization of the landscape and the privatization of space. In some sectors, there is no occupation of the sea cliffs, however the small stretch of beach strip makes the vulnerable side to wave action. It was also noted, through physical, chemical and microbiological analyzes, the quality of water from community wells is committed to consumption, especially in areas of high population density. In this sense, one should promote the management of the area, being necessary to know the coastal carrying capacity with cliffs with a view to preventing and minimizing possible negative influence on natural systems and human populations that live in the surrounding areas of these environments.