More than 40% of areas are highly vulnerable. Irregular land occupation worsens the situation
The natural beauty and biodiversity of coastal regions can hide a highly fragile scenario from an environmental point of view. Sensitive to physical changes and human action in places, these are areas that require detailed study and planning, so that flora, fauna and human communities can live in harmony, without bringing risks to the environment or being harmed by it. In the State of São Paulo, the South Coast region, which covers the cities of Iguape, Cananéia and Ilha Comprida, is a clear example of this reality. The place is one of the poorest in the State and, since the country's colonization period, has suffered from the effects of extractivism and the lack of planning for the occupation of its lands.
To assist public authorities and institutions responsible for this type of organization, a doctoral research, carried out at the Unicamp Institute of Geosciences, investigated the natural and human reality of these cities and crossed geographic and social data to map the environmental risks to which the region faces. is submitted. The author of the thesis is Edson Antonio Mengatto Junior, which was guided by the teacher Regina Celia de Oliveira (IGE) and teacher co-guidance João dos Santos Vila da Silva (Embrapa). In addition to identifying the points of greatest environmental risk, the research also draws attention to the advantages of using geoprocessing information for this planning and the importance of local residents knowing this data, so that they themselves can be agents of preservation. of the area.
Environmental vulnerability: union of factors
Edson is a geographer graduated from Unicamp and has a master's degree in Geography also from the university. He chose to work with mapping the areas of the southern coast of São Paulo after learning more about the work carried out by the Center for Studies in Coastal Areas (NEAL). Together with the group, he decided to apply the knowledge about georeferenced information systems, gathered throughout his career developing research at Embrapa Informática Agropecuária. According to Edson, the option to analyze the southern coast of the state was mainly due to the possibility of studying and contributing to an area that still has little data gathered on the physical aspects and social development of the population, with existing data being difficult to access. .
The research proposal was then to offer the local population and those responsible for making decisions on regional development a mapping of the areas of greatest environmental vulnerability in the region. To achieve this, it was necessary to give the locality a broad look, which involved both the physical aspects of the region, such as topography, geology and relief compartmentalization, as well as the social characteristics of the community, such as education, employability and access to basic services such as running water. and sewage collection. This is because environmental vulnerabilities are measured based on the assessment of physical and social data.
"We work with the concept of physical susceptibility so that we can understand the period of formation of this area, which makes erosion processes more accelerated due to the recent period of formation. When we work with social vulnerability, we speak specifically about man located in these regions, and when we think about these places we talk about a process of occupation of these regions in a disorderly manner, where there is no adequate planning and then some regions can suffer extremely serious consequences", explains Edson.
Plains present more risks
The South Coast region of São Paulo comprises an area of around 3,4 km², being predominantly flat. The highest altitudes are found in the north of the municipality of Iguape, still in the Serra do Mar region, and on the border with Paraná. Faced with relief like this, those who are used to seeing hillside regions suffer from the risk of landslides, as happens in cities on the North Coast, in Baixada Santista and in other regions of the Brazilian coast, may think that the area is practically immune to the effects. of erosion. But the opposite is true: the plains are precisely the most sensitive to erosion, making the entire region susceptible to physical processes.
This is due to the fact that it is a place of recent geological formation, with little time for the materials to consolidate. "On the South coast, the steepest areas are made up of older formations, derived from the Precambrian period, which means that erosion processes occur more intensely in the flatter areas, in the coastal plains. This occurs because they are areas of formation recent, from the Quaternary period, which makes these regions extremely susceptible, they suffer erosive and depositional processes with much more intensity", explains Edson, who also points out as risks to the region the increase in tides and the advancement of the coastline, especially in sea undertow events, which has especially harmed residents of the northeast zone of Ilha Comprida.
Another determining factor for the risks suffered by the region is the way in which it has been explored over the years. Edson comments that the occupation of these areas dates back to the country's colonization period, a time when rice cultivation for the colony, after the empire, represented 90% of the local economy. The damage to the environment worsened after the opening of the artificial canal Valo Grande, in 1852, connecting the Ribeira River to the Port of Iguape. It was built to facilitate the flow of production to the ocean and allow larger ships to enter the region. However, the intervention increased the risks of erosion on the coast and damaged mangrove areas. "It is important for us to remember that, in addition to physical training itself being a recent process, which makes it quite susceptible, we also associate man, who accelerates the processes within the occupation of this area", highlights the researcher.
Effects on human development and environmental vulnerability
Today the occupation of the coast of São Paulo is governed by Law 10.019 / 1998, which establishes the State Coastal Management Plan. According to him, the State's coast is divided into four distinct regions: North Coast, Baixada Santista, Vale do Ribeira and Iguape-Cananéia Estuarine-Lagunar Complex. Unlike the North Coast and Baixada Santista, the zoning of Vale do Ribeira and the Iguape-Cananéia region are still being developed, leaving the area vulnerable to irregular occupations and undue exploitation of natural resources.
Data from the Municipal Human Development Index (HDI) surveyed by the research show that the three cities - Cananéia, Iguape and Ilha Comprida - have been going through a development process from 1991 to 2010, to which the data refer. Cananéia went from an IDHM of 0,450 to 0,720, Iguape went from 0,473 to 0,726 and Ilha Comprida went from 0,451 to 0,725. According to the scale, the human development of cities is calculated from 0 to 1, the greater the development, the closer the index is to 1.
However, the municipalities are still behind other regions on the coast of São Paulo. According to the Brazilian Human Development Atlas, São Vicente, in Baixada Santista, had an MHDI of 0,768 in 2010. Caraguatatuba, on the North Coast, had the index calculated at 0,759.
The thesis also evaluates data that calculates the vulnerability of the three municipalities, taking into account characteristics such as the average income of residents, longevity and education. Information was compiled from two indices, the São Paulo Social Responsibility Index (IPRS) and the São Paulo Social Vulnerability Index (IVPS). Both classify cities into classes and groups, from the most developed to the most deprived. According to the IPRS, Cananéia has good social indicators, despite low wealth. However, Iguape has indicators considered intermediate and Ilha Comprida, unsatisfactory indicators. The IPVS points out areas of medium and high vulnerability in the three municipalities.
Thus, crossing data relating to the physical aspects of the region with information on the human development of the place, the researcher arrived at the result of the area's environmental vulnerability index, organized on a map. According to him, 42% of the entire region presents high vulnerability, 27% medium vulnerability, 19% low vulnerability and 11,7% very high vulnerability. Only 0,05% of the region has a very low vulnerability index.
Access is important for planning
The research carried out by Edson brings important contributions to city halls, departments and government spheres responsible for developing urban planning and land occupation policies. However, he argues that it is also necessary to guarantee this access to the population, through open data systems, such as WebGIS systems. According to him, as people become familiar with information about the region where they live, they begin to contribute to more conscious land use and also demand concrete policies and actions from public authorities.
"It is important that these surveys do not just remain at work, but that they expand across these regions and by public authorities, as it is a region very lacking in information. And, the more information that is made available, through scientific articles or work carried out in these regions, it will be possible to make progress in planning and decision-making conditions on the part of public authorities, using data produced by universities", reflects Edson, who hopes to see his work helping in the development of the South Coast of the State.
