Climate extremes related with rainfall in the State of Rio de Janeiro,Brazil: a review of climatological characteristics and recorded trends

This paper presents a synthesis of the main characteristics of precipitation in the State of Rio de Janeiro (Brazil) based on extreme rainfall indicators. Daily precipitation data are derived from 56 rainfall stations during the second half of the twentieth century and the 2000s. Eight indices related to extreme precipitation were analyzed. The Mann–Kendall nonparametric test and the Sen's Curvature were employed to evaluate the significance and magnitude of trends. The primary climatological aspects and identified trends throughout the last decades are discussed, besides the hydrometeorological impacts associated with them. Lower values of annual total precipitation are recorded in northern Rio de Janeiro (around 800 mm) and higher in the southern State (up to 2,200 mm). The Serra do Mar affects the frequency of heavy precipitation, and the areas near the sea and high relief present the highest values of consecutive days with expressive rainfall (more than 150 mm in 5 days). These areas also showed a high concentration of flood and landslides events. Most of Rio de Janeiro exhibits precipitation intensity of about 13 mm/day. The maximum number of consecutive dry days shows a gradient from the coast (about 30 days) to the State's interior (around 50 days). Regarding trends, there is a growth of accumulated extreme precipitation in various stations near the ocean. The extreme rainfall in 24 h displays an increase in most Rio de Janeiro (+?1 to?+?5 mm/decade). The consecutive dry and rainy days present similar signs of decreasing trends, suggesting irregularly distributed precipitation in the State. This study is especially relevant for decision-makers who need detailed information in the short and long term to prevent natural hazards like floods and landslides and the related impacts in the environmental and socioeconomic sectors of the Rio de Janeiro.

     

The use of geoprocessing to assess vulnerability on the east coast aquifers of Rio de Janeiro State,Brazil

The east coast of Rio de Janeiro State, Brazil, shows a worrying overlap between areas with intrinsic groundwater vulnerability and the most significant urban expansion zones. It experienced a rapid population growth in recent years, mainly due to the tourism industry, resulting in a significant pressure on drinking groundwater resources. In this regard, development and use of techniques to control and protect areas susceptible to contamination is crucial. The elaboration of aquifer vulnerability maps is thus extremely helpful to support water resources management. The aim of the work is to present the methodological approach in the use of Geoprocessing techniques to obtain a suitable groundwater vulnerability model in Rio de Janeiro east coast. Considering the existing problems and the current land use and characteristics of the study region, it is clear that the most vulnerable areas (that is, “extreme” and “very high” vulnerability areas), coincide with the most significant zones of urban occupation, corresponding to 11% of the total study area, demanding adoption of urgent measures in the near future. Geoprocessing tools and remote sensing for characterization of Rio de Janeiro’s east coast aquifer vulnerability gave good results, representing a satisfactory method for management actions at low cost.     

Hot spot volcanic tracks and their implications for south American plate motion,Campos basin (Rio de Janeiro state), Brazil

The spatial and temporal arrangement of volcanism produced by hot spots potentially can reveal the history of lithosphere plate drift. From the age of these igneous bodies, it is possible to estimate not only the drift speed of plates but also the timing of eventual route changes. This article concentrates on the apparent link between both the Poços de Caldas–Cabo Frio alkaline rocks alignment (Rio de Janeiro state) and the Vitória–Trindade chain (situated on the oceanic crust adjacent to Espírito Santo state, Brazil) to a single fixed hot spot. On the basis of geological, geomorphological, and geochronological evidence, the authors propose that the South American continent may have experienced a clockwise rotation during the Eocene, which resulted in the relative displacement of hot spot volcanic manifestations from Cabo Frio (Rio de Janeiro state) to the western border of the Vitória–Trindade chain. At this time, several tectonic, sedimentary, and magmatic events took place that were capable of causing the inferred Eocene displacement. It is worth noting the coincidence between the northeastern trend of the oil fields of the Campos basin and the suggested path of the basin as it moved over the hot spot.     

Evaluation of community leaders’ perception regarding Alerta Rio,the warning system for landslides caused by heavy rains in Rio de Janeiro

Warning systems help reduce damage and save lives in disasters; however, there is a lack of research analyzing the population perception of these systems. In Rio de Janeiro (Brazil), because the city slums face the risk of landslides caused by heavy rains, a siren early warning system named “Alerta Rio” was installed in 102 areas. The purpose of this paper was to understand the perception of community leaders regarding this alert system. To this end, a survey was conducted with community leaders to collect data on whether and why the public do or do not attend to the alert. Results indicated that (1) public adherence to Alerta Rio is low despite the generally positive view of the system, (2) local violence was reported as the reason for staying at home to protect one’s property, and (3) problems with temporary shelters and the routes to them result in lack of people’s involvement in the system. Whereas these factors are similar to population perception regarding other warning systems, the community leaders also raised the public’s lack of trust in the city hall’s adopted concept of risk and in the politicians as a relevant factor in the population perception of Alerta Rio. These factors, together with the lack of prevention policies complementary with the alert system, led to perception of reduced importance of the system. For potential solutions to enhance alarm compliance, this study recommends improvement in communication, educational programs, and public engagement strategies tailored for each target group.     

Climate and global change in relation to sustainable development: The challenge to science

In the light of the current worldwide concern on climate and global change and the outcome of the United Nations Conference on Environment and Development held in Rio de Janeiro, Brazil in 1992, the paper relates climate and global change to sustainable development. It emphasizes the importance of scientific research in the advancement of knowledge in the related areas. The role of science to socio-economic development is discussed in the context of the symbiotic relationship between science and society. In this connection, the four areas identified by the Rio Conference are discussed.     

Disaster education for landslide risk reduction: an experience in a public school in Rio de Janeiro State,Brazil

Public policies for reducing the disaster risk associated with landslides in Brazil, based almost solely on the implementation of engineering works to stabilise hillsides, have proved ineffective, with this type of disaster becoming more common and more severe. There is therefore an urgent need to form a culture that encourages the public to participate directly in disaster management and develops community capacity, which requires a broad disaster education programme on formal, non-formal and informal levels. Given the recent approach to the topic, this study aims to contribute to the development of a disaster education methodology for landslides, based on an experience that was coordinated by the authors within formal education. The experience was implemented in a state school in the city of Niterói (Rio de Janeiro State, Brazil) which is recurrently affected by disasters associated with landslides. The issue of disasters associated with landslides was addressed in a one-semester course, using the theory of meaningful learning and a range of pedagogical tools in both theory and practical classes, for a total period of 16 h. The educational activities were preceded by a landslide risk perception survey and teacher training. The study concluded that the course promoted interactive and participatory learning, a connection to the real problem in the field and an affective relationship with the issue.     

Reviewing urban revitalisation strategies in Rio de Janeiro: from urban project to urban management approaches

This paper describes key urban development strategies pursued during the last seven years by the Municipality of Rio de Janeiro, the second largest city in Brazil. It discloses internal processes, organisational restructuring of the municipality and institutional changes geared to increase effective urban management and resource mobilisation required to implement multiple sector programmes and key projects in several locations in the city like Favela Bairro and Rio Cidade Programmes, The Rio Strategic Plan, etc. It is argued that the formation of interdepartmental working groups for better horizontal articulation of policy making and implementation, the creation of the financial and accounting unit, the decentralisation of authority towards sub-municipality levels, and capacity strengthening of its personnel – among other things – have made a positive impact on the performance of local government. The paper further highlights a significant change towards policies of urban consolidation and revitalisation of declined areas of the city supported by heavy public investments and the effort towards broader civil society involvement in municipal projects. Municipal autonomy, problem-solving and result-oriented type of planning and management and organisational change are some of the lessons pinpointed by the paper for a city of that size and complexity.     

Towards a better understanding of the evolution of the flood risk in Mediterranean urban areas: the case of Barcelona

This contribution explores the evolution of the flood risk in the Metropolitan Area of Barcelona (MAB; Northeast Spain) from 1981 to 2015, and how it has been affected by changes in land use, population and precipitation. To complete this study, we analysed PRESSGAMA and INUNGAMA databases to look for all the information related to the floods and flash floods that have affected the chosen region. The “Consorcio de Compensación de Seguros”, a state insurance company for extraordinary risks, provided data on economic damage. The extreme precipitation trend was analysed by the Fabra Observatory and El Prat-Airport Observatory, and daily precipitation data were provided by the State Meteorological Agency of Spain (AEMET) and the Meteorological Service of Catalonia (SMC). Population data were obtained from the Statistical Institute of Catalonia (IDESCAT). Changes in land use were estimated from the land use maps for Catalonia corresponding to 1956, 1993, 2000, 2005 and 2009. Prevention measures like rainwater tanks and improvements to the drainage system were also been considered. The specific case of Barcelona is presented, a city recognised by United Nations International Strategy for Disaster Reduction as a model city for urban resilience to floods. The evolution of flood events in the MAB does not show any significant trend for this period. We argue that the evolution in floods can be explained, at least in part, by the lack of trend in extreme precipitation indices, and also by the improvements in flood prevention measures.     

Multicriterial analysis in the investigation of favorable areas for edifications with shallow and deep foundations in the Municipality of Campos dos Goytacazes — Rio de Janeiro, Brazil

The Municipality of Campos dos Goytacazes is located on the northern coast of Rio de Janeiro, Brazil. The city developed on a floodplain and as a consequence of this occupation it has experienced problems with the water table level, drainage system, soil carrying capacity and aquifers' contamination. The purpose of this paper was to accomplish a geological and environmental study, producing interpretive and derived geotechnical maps to analyze the degree of aptitudes or restrictions of the physical environment for urban expansion. In order to do this, the methodology of multicriterial analysis was used, combined with pedological indicators resulting in the elaboration of the Favorability Maps for Buildings (Shallow and Deep Foundations). The remote sensing tools, GIS and GPS, sped up the elaboration of the Information Plans. The maps generated in this work allow us to indicate problems in the physical environment serving as a guide to urbanization. It was verified that the city expands into unsuitable areas and it is recommended as areas for expansion those considered favorable in the outcomes of this research.     

Poverty tourism: theoretical reflections and empirical findings regarding an extraordinary form of tourism

During the mid-1990s, a new form of tourism was established in metropolises of several developing countries or emerging nations. This type of tourism consists in visits to the most disadvantaged parts of the respective city. Poverty tours or slum tours are offered on a relatively large scale in the South African cities of Johannesburg and Cape Town, Rio de Janeiro in Brazil, as well as in Indian metropolises, to name some important examples. The target group of these tours consists primarily of international tourists. It is estimated that 40,000 such tourists visit favelas in Rio de Janeiro each year, around 300,000 the townships in Cape Town. This contribution refers to and comments on these developments and insights regarding poverty tourism or slumming, based on empirical research and experiences in South Africa, Brazil, and India. It will be shed light on the phenomenon from an observational-theoretical perspective. It is aimed to open a discussion on the ways poverty tours or slumming observes and simultaneously programmatically charges poverty. And, it will be considered in which way poverty tourism is observed.     

Paradoxes of modernity: imperial Rio de Janeiro, 1808–1821

This paper examines the spatial dynamics of urbanism in Rio de Janeiro during the early nineteenth century. Conventional narratives of modernisation fail to capture the complexities of this moment, between 1808 and 1821, when the city replaced Lisbon as the capital of the Portuguese empire. The position of colony and metropolis were inverted, Portuguese absolutism was bolstered by British liberalism, and a market-economy arose alongside the expansion of slavery. As the newly-created imperial capital, Rio felt the effects of these various transformations: the physical boundaries of the city rapidly expanded, its economy diversified and the cultural life of the city was re-shaped. Our aim in this paper is to understand this particular moment of urban transformation as a product of the intersection of global networks of trade, slavery and industrial capitalism. Rather than depicting the historical geography of the city as a passive space for European conquest and expansion, we consider the extent to which its urban dynamics were shaped by a distinct local geography of globalisation. In particular, we examine the interrelated spatialities that are part and parcel of the modernising process.     

Taphonomic aspects of the Pleistocene vertebrate assemblage of Itaboraí, state of Rio de Janeiro,southeastern Brazil

Pleistocene vertebrates from Itaboraí Basin have not been taphonomically studied prior to this work, limiting the understanding of the deposition and preservation of the only Pleistocene vertebrate accumulation known for the state of Rio de Janeiro. In this work, the taphonomic signatures of the Pleistocene vertebrate assemblage of Itaboraí are identified and interpreted in order to increase the knowledge about the formation of this fossil association and the paleoecology of the region of Rio de Janeiro during the late Pleistocene. Our analysis shows that the thanatocoenosis was exposed to the biostratinomic processes during a small time span; that it is parautochthonous; and experienced short transport distances by normal fluvial streams and floods. Subsequently, the fossiliferous horizon was quickly covered by the superjacent soil. Yet, the skeletal elements were fractured and deformed during the sedimentary compaction. The differential preservation of megamammal bones is associated to the bone resistance against those destructive processes and to the specific anatomical features. Comparison between Itaboraí and other Brazilian Pleistocene vertebrate accumulations shows that the Itaboraí fossil accumulation was less affected by taphonomic processes, although it is also a time-averaged fossil concentration. Finally, some of the taphonomic features indicate an arid paleoclimate.     

Long-term monitoring of the behavior of a talus-colluvium deposit

Landslides - This article describes the behavior of a talus-colluvium deposit up to 70-m thick located in the Serra dos Orgaos, Rio de Janeiro/RJ, Brazil. The monitoring dataset of 13 years...     

Resilience and brittleness in the ALERTA RIO system: a field study about the decision-making of forecasters

Natural disasters, particularly those triggered by heavy rainfall, may cause major damage and death. However, if an accurate early warning is issued, the damage can be mitigated. In Latin America and Brazil, characteristics of socioeconomic development often lead to a disorderly growth of cities and, consequently, occupation and irregular construction in risk areas. Therefore, forecasts of heavy rainfall, as well as preventative and mitigatory actions based on meteorological data/alerts, are essential to saving lives and minimizing material loss. An event that would have benefited from such actions is that which occurred in the mountainous region of Rio de Janeiro in January 2011, when over 800 people lost their lives. This work describes the first research initiative on resilience engineering domain in systems to forecast heavy rains in Rio de Janeiro. The results indicate important sources of brittleness in the system that supports the work of meteorologists, mainly related to the technical and organizational framework, and suggests that the main source of resilience in dealing with critical situations is the tacit knowledge of experts.     

The favelas of Rio de Janeiro: A temporal and spatial analysis

A spatial and temporal analysis, at a city wide scale, is given of the main type of informal housing (favelas) in Rio de Janeiro. Rapid change in the number and distribution of favelas and their inhabitants (favelados) over time is seen as the outcome of two opposing sets of factors. Demand-led housing factors, including population growth and variations in levels of poverty in the city, have constantly outstripped the supply side of the housing equation where inadequate housing policies and investment, together with restricted building land have been characteristic. Added to these factors are a set of more specific developments which shape the favela geography, including the timing and location of urban redevelopment, favela eradication and recognition, transport development and access by the favelados to employment sources. Evidence shows that the contemporary distribution of favelas in the city does not conform to spatial models of this urban form, and that any interpretation of the Rio favelas, including their growth, development and diversity, needs to be space and time specific. This revised version was published online in July 2006 with corrections to the Cover Date.     

On the Effect of Thermally Induced Stresses in Failures of Some Rock Slopes in Rio de Janeiro, Brazil

Previous studies have indicated that many rock slope failures in Rio de Janeiro, Brazil, occur during relatively dry periods when there is little, if any, rainfall. In the present paper, we describe these events and propose possible mechanisms for their occurrence. It is believed that daily fluctuations in temperature may create thermally induced stresses of enough magnitude to propagate fractures already existing in the rock mass. Laboratory experiments were conducted in order to measure temperature variations in a fractured rock system. Using the experimentally obtained data, we carried out numerical analyses in order to verify whether temperature-related stresses were indeed able to propagate fractures existing in the rock mass. The results obtained indicate that cycles of temperature change over time, especially during the colder months of the year can indeed create stress conditions in the rock mass able to propagate existing non-persistent joints, and ultimately lead to failure of the rock slope.     

Supportive elements to the decision-making process in the emergency planning of the Angra dos Reis Nuclear Power Complex,Brazil

Accidents in nuclear power plants are problems of great complexity, mainly due to their consequences, such as the population evacuation from the enterprise influence area. The decision-making and emergency plans must be well articulated and require good local geographic space knowledge and the interactions of their environments. This study is a contribution to the emergency plans for the Almirante Álvaro Alberto Nuclear Power Plant, currently the only nuclear complex in Brazil, located in Angra dos Reis, Rio de Janeiro. The study confirmed the region’s main geoenvironmental aspects as winds and rainfall, landslides and population density were evaluated as important elements in the local emergency process. Their integrated analysis supported scenario identification and critical regional points and highlighted population evacuation escape routes. These important results characterized the support to local emergency management actions and guidelines. Furthermore, the geographic information systems was configured as an integrated spatial and temporal analysis platform to associate meteorological, geological/geomorphological and socio-economic data, playing a key role to support the evacuation planning in the event of nuclear power plant accidents.     

浅析甘肃小流域分布特性及山洪灾害成灾特点

暴雨洪水是自然界的主要灾害之一,它是水文现象的极端事件。山洪给国民经济和人民的生命财产造成很大损失,它是甘肃经济社会发展的重要制约因素之一。随着经济发展,人口增加,山洪给国民经济和社会发展带来的损失将越来越大,因此,防洪减灾任务仍十分艰巨。本文对甘肃省小流域分布特性及山洪成灾特点进行了分析,并提出了山洪灾害防治的建议。