Adaptações e percepção da população a eventos de ressaca do mar no litoral de Maricá, Rio de Janeiro, Brasil Translated title: Adaptation and perception of extreme storm events at Maricá's Coast, Rio de Janeiro, Brazil

Abstract

O presente artigo destaca a importância do estudo da percepção e das adaptações das pessoas e do poder público local frente ao impacto de eventos de ressaca do mar tendo como estudo de caso o litoral de Maricá, Rio de Janeiro. Este município situado a 60 km a leste da Baía de Guanabara é formado por duplos cordões litorâneos e lagunas à retaguarda. A orla estudada apresenta-se de modo geral muito exposta às fortes ondulações do quadrante sul. Três fortes ressacas desde a década 1990 causaram graves impactos em diversos segmentos deste litoral, com destaque para a uma ocorrida em maio de 2001 quando diversas construções foram destruídas, o que gerou elevado prejuízo financeiro. Considerando tais epsódios o presente trabalho buscou analisar as diferentes respostas adaptativas realizadas, assim como a percepção sobre os riscos de danos, causas e soluções relacionadas com esse fenômeno. Estudos prévios demonstraram que o grau do estrago sofrido variou de acordo com as principais características oceanográficas (relacionadas à refração das ondas), geomorfológicas (granulometria, morfodinâmica praial e presença de dunas vegetadas ou não) e urbanas (densidade de ocupação e posição das casas, em relação ao perfil praial). Danos muito intensos, com destruição total de casas, quiosques e da avenida beira-mar ocorreram, principalmente, na praia e Barra de Maricá. Os prejuízos foram estimados em 200.000 reais/km. Para caracterizar as principais adaptações, após a ressaca de maio de 2001, realizaram-se trabalhos de campo, entre 2002 e 2005, quando foram feitas observações in loco, registros fotográficos e localização, por meio de GPS, das medidas realizadas. Para avaliar a percepção, aplicaram-se 65 questionários, à população da orla de Maricá, nos anos de 2003, dois anos após a considerável ressaca, de maio de 2001, e no presente ano, ou seja, 14 depois. Os resultados do atual trabalho demonstraram que as respostas adaptativas foram feitas, exclusivamente pelos moradores, donos de casas de veraneio ou donos de quiosques, sem qualquer apoio do poder público local. Identificaram-se diversos tipos de obras, tais como muros de proteção, enrocamentos e aterros. As entrevistas revelaram que o perigo do mar, a agressividade das ondas e as ressacas são percebidos como o principal problema da praia de Maricá, pela maioria das pessoas entrevistadas. Além disso, tanto em 2003 como em 2015, grande parte dos entrevistados afirmou acreditar que suas propriedades encontrar-se-ão em risco, caso haja novas ocorrências. Quase todos citam as mudanças climáticas, a subida do nível do mar ou outros fatores naturais, como causas do problema. O sentimento de risco ocasionou ainda um processo de desvalorização imobiliária, principalmente nos dois anos seguintes à ressaca do ano de 2001. Tal processo não é mais apontado, atualmente, como um problema por grande parte, dos respondentes, embora alguns alertem que as casas na beira mar não conseguem ser vendidas facilmente. Os dados encontrados, associados à análise espacial da vulnerabilidade física do litoral e dos danos sofridos em eventos de tempestade, são considerados essenciais para o desenvolvimento do planejamento e gestão costeira integrada.

Translated abstract

This paper highlights the importance of researching people's perception of the impacts caused by extreme storms on beaches as well as their adaptation strategies to adjust to such events. The assessment of people's level of consciousness about the problem, as well as their responses to it, helps us understand their ability to adapt and recover from the stress suffered. Therefore, the adaptation degree and the concept of social resilience are considered essential aspects of coastal zone management. The present study focuses on the city of Maricá, which sits east of the Guanabara Bay, 60km (37 miles) from Rio de Janeiro City. The Maricá coastal zone is formed by double beach barriers and barrier-enclosed lagoons. The inner barrier was formed in the second to last Pleistocene marine transgression. The other barrier is associated with the Holocene transgression. The east-west coastline orientation exposes the beaches to high southern waves and strong winds associated with cold fronts. Maricá's urban growth began in the 1970s. Between 1990 and 2000, this city experienced one of the biggest urban growth in the state of Rio de Janeiro. Today, Maricá has 125,532 inhabitants, a 66% growth in comparison to 2000. Weekend getaways tourism is the major incentive for this expansion. These second homes are concentrated on beaches and around the lagoons. Nowadays, despite the demographic pressure, Maricá's coastline is becoming a strategic geographic area because of two events with economic impacts that are scheduled to take place in the near future. The first will be the construction of a port at Jaconé Beach, which included sea defenses structures. Second, a vacation resort is to be installed at the Environment Protected Area located at Barra de Maricá Beach. Three storm events occurred in 1995, 1996, and 2001. These events caused several impacts on Maricá beaches, damaging houses, avenues, and commercial kiosks located at the coast. The strongest storm in decades took place in 2001; the impacts on Maricá's shore were one of the most severe in the state of Rio de Janeiro. The results of Maricá coastline's vulnerability assessment found in previous studies showed that the degrees of wave exposure, beach fragility, and damages varied according to geomorphologic, oceanographic, and urban characteristics. These studies also evaluated the resulting financial losses and depressed housing prices. In this context, this paper aims to assess different forms of adaptation, as well as people's perceptions of storms impacts on Maricá coastline. Twenty-five people were interviewed in 2003 and others fourteen in 2015 at the beaches or proximities in Maricá. Twenty eight of which were local residents, owned vacation homes, twelve worked at commercial kiosks, and six were housekeepers. Fieldwork consisted of observation of damages as well as repair or protection strategies. The interviews showed that people consider the dangers of the sea as the major problem in Maricá's beaches. Other common urban coastal problems, such as sea pollution and conflicts over the use of resources were not mentioned at all. Moreover, results showed that adaptation actions were done privately. There were neither prevention measures nor public financial support. People worked to mend and protect their homes in distinct ways. Predominantly, they used coastal hard engineering solutions, like seawalls. These seawalls were built using a variety of materials, such as concrete, culverts, and riprap. Besides seawalls, some residents built an embankment, filling areas with sand. Residents also took responsibility for repairing the ocean drive avenue. They focused their efforts in front of the impacted area advancing over the beach berm. As noted, non-professionals carried out several adaptation strategies and actions without any planning at all. Hence, other solutions, such as moving the urban settlements back or the establishment of a protected area, were not even considered. With no guidance whatsoever, people felt insecure about the efficiency of the structures. The interviews also revealed that people's perceptions of the causes of storm impacts were strongly influenced by the climate change and sea level rising debates. This point of view can be perceived as a problem, because it indicates a disconnection from other causes that might be influencing the current process, such as local geographic characteristics. Moreover, the lack of advocacy is also tied to this perception since the locals tend to see these events as of exclusively natural causes. Therefore, they believe political measures will not solve the issue. Finally, the fieldwork campaigns contributed to identify the spatial positions of the adaptation actions that were made. In addition to this identification, spatial analysis of the physical vulnerability and damages suffered at storms resulted on the following findings. In heavily damaged areas, 50% built seawalls, 12% embankment, 17% only repaired the damages, and 2% carried out mixed actions. In moderately damaged areas, only 26% built seawalls and 27% embankment, while 47% only repaired the damages. Hence, when the damages suffered were heavy, the preferred option was for “hard” engineering solutions. The results indicate specific demands for appropriate coastal management. The local government needs to offer financial support and take responsibility for leading and guiding preventive as well as repairing actions. Moreover, educating locals to increase their knowledge about the problem is essential. Furthermore, in order to obtain a complete and integrated coastal vulnerability assessment, studies about adaptation strategies and people's perception should be incorporated to spatial analysis of the physical vulnerability. This is especially important on coastal cities such as Maricá that has become a strategic place for new economic activities, and where local beaches are going through an intense urban growth.