Using the information system and multi criteria


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utilização dos resultados do mapeamento na priorização dos programas habitacionais de São Paulo

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Using the information system and multi criteria

  1. 1. Proceedings of the Second World Landslide Forum – 3-7 October 2011, Rome Eliene Coelho(1), Luciana Pascarelli(2) Using the information system and multi-criteria analysis in the geological risk management in São Paulo (1) PMSP, São Paulo City Hall, Habisp, Sao Paulo, Brazil. (2) Consultancy Services and Technical Works Department, Sao Paulo City Hall, Rua Libero Badaro, 425, BrazilAbstract Since 1980´s the surveys space could not 355 km2 to 1.370 km2 in approximately five decades.definitely follow the growth and the density of favelas, Due to the method adopted by real estate speculationand some communities started to trigger the first when it came to dividing the land in the city, “urbanrecords of accidents in areas hitherto stable. The vacuums” were generated and subsequently occupied bymapping made in 2010 is today the largest geological- shanty towns and irregular land occupation. Areas ofrisk database in the country. Today, all these greater environmental fragility, such as slopes andinformation are included in the “Habisp”. Habisp is a banks of streams also began to be occupied, above all atmapping system of precarious settlements in the city of the end of the 1970´s. At the end of the 1980`s, thereSao Paulo, which contains valuable information to face exists a record of the first accidents on slopes and in thethe urban poverty. Poverty which is materialized in Sao mid 1990´s, these become ever more frequent and lessPaulo in many ways of informal settlements: slums, localized, revealing that a considerable part of theirregular settlements, tenement housing, temporary population occupies these areas of risk.housing and degraded sets. The Habisp stores,organizes, processes and produces high quality Mapping the risk areas in the city of São Paulogeographic information, which serves as support for thetechnicians of the Housing department in making At the end of the 1990´s, geotechnical companies carried out an analysis of the risk on the slopes of 240decisions. The results have been making possible shanty towns, identifying about 60% of the situations atreassessment and adjustment of the low-incomeintervention projects by the government, prioritizing risk for landslides. Although such information has been used for the planning and execution of localhousing, social-educational infrastructure, and basic- interventions, activities to control and prevent suchsanitation actions in areas of greatest susceptibility. risks per se have been negligible for about a decadeKeywords: mapping, susceptibility, geographic (1993 to 2001), whilst at the same time the occupation of the hills grew significantly. Cartographic registries andinformation, priority those of occurrences were also rare, making it impossible to carry out any sort of planning with theThe risk of landslides in large urban centers necessary efficacy.Mass movement processes are natural and a part of the In 2010, the City Hall of São Paulo, along with thecycle/depositional erosion responsible for determining Institute for Technological Research (IPT) came to thethe scenery of the Earth’s surface. Nevertheless, when as conclusion of the need for “Analysis and risk mappingthe result of a geological process there is an impact on associated to landslides in the areas of slopes and thehuman beings or their property, what comes to light is banks of rivers and streams in shanty towns in the Sãothe concept of a geological accident, implying that Paulo municipality”. More than a geotechnical survey,besides the physical process some causes of instability the mapping geared its focus on the areas of precariousalso lead to the consequences observed. The first tales occupation, where the population’s vulnerability wasof accidents of this sort in the city of São Paulo relate to the steepest. In such sites, any type of event, even theurban expansion. More fragile areas, such as slopes and minor ones could entail significant damage for theriver banks began to be occupied without the community, vis-a-vis their low perception of risk andappropriate planning, and the growing number of the inability to set forth a speedy response and recovery.people affected by the landslides revealed that there was The risk estimates were analyzed quantitatively,a considerable part and parcel of the population living based on field observations, integrating the analysisin risky settlements. parameters contained on a risk card, with the support of In the city of São Paulo, the first tales of accidents aerial images.of this nature are directly linked to the urban expansion The 407 areas investigated were subdivided intorecorded since the beginning of the 1930´s. According to risk sectors, due to the fact that the characteristics ofNogueira (2002), the urban spot in the city grew from the land and above all of the occupations posed
  2. 2. E. Coelho, L. Pascarelli - Using the information system and multi-criteria analysis in the geological risk management in São Pauloenormous variations within a single shanty town. For land settlements, tenements or slums and housingeach of the sectors, what was evaluated was (1) natural enterprises conceived for the population that lives inparameters referring to the type of soil topography, those areas.natural structures that conditioned land movements, To understand how it operates, it is necessary totypology of water courses and type and breadth of explore some conceptual issues regarding thevegetation and (2) occupational parameters such as the importance of Information and Communicationlevel of interference in the land, the presence of basic Technology (ICT) in our present day society. It is alsoinfrastructure to supply water, garbage collection and necessary to refer to the issue of making decisions, thesewage treatment, the condition of public roads and construction of indicators and their content, objectivesstructure of the homes themselves. Additionally to the and the dynamism relating to the problem of which it issigns of instability observed, the parameters assessed a part: popular housing.ended up in the creation of 1.179 risk sectors, with Habisp arose from an initiative to draw up aspecific levels of criticality according to Table 1. strategic plan for social housing, within the realm of the project with Alliance with Cities, and throughout theTable 1: Criteria to rank the degree of risk (simplified from the studies, it turned into a proposal to draft a MunicipalIPT- 2006) Housing Plan (MHP). Without the Habisp and the Degree of Description System of Priorities, both planning instruments, the probability MHP would not have attained its present day level of Slopes with little inclination (<17º), natural and sophistication and detail. The proposal encompasses R1 on stable soils with low probability of having goals and objectives to service housing needs until the landslides. Absence of indices of instability. This is the least critical condition. year 2024, including the cost for urbanization Slopes with slight inclination with a medium interventions and land ownership regularizing and the probability of having a landslide. There is construction of new housing units, settlement per evidence already of incipient instability. If the settlement (consult the Municipal Housing Plan: R2 existing conditions are maintained, there is a document for debate,, Figure 1). slight probability that there will be destructive Data, information, indicators, knowledge episodes occurring during intense rainfall. generation, decision making, geographic spaces, Inclined slopes (>30º) point towards a high popular housing, regularization of land ownership, potential for developing landslide processes. spatial analysis, maps, registries and population surveys R3 There is a large amount of evidence regarding are some of the issues that Habisp relates to. To classify instability (cracks on the soils, levels of subsidence of the soil, etc.) it into a single system modality is not an easy task, these Evidence of instability is expressive (quantity subdivide into categories, in accordance to the activity and magnitude). This is the most critical they support, but Habisp does not fit into a single R4 condition. Under such conditions, it is highly category, and can be deemed to be a system for probable that there will be destructive events managerial information; a transactional processing during intense episodes of rainfall. system or a decision making support tool (BIDGOLI, 1989, apud BARBOSA, 2002). More than a geotechnical survey, this broader As part of this classification set forth by Bidgolimapping already carried out in Brazil focused (1989, apud BARBOSA, 2002), we can state that Habispexclusively on settlement areas where the population’s is mostly a management information system, that cansocial vulnerability was high. In these sites, any type of be used for planning, control and decision makingevent, albeit the smallest ones could cause significant purposes; condensing or summarizing the informationdamage to the community, given their low perception obtained from the transactional data processingof risk and limited ability to respond to the event and systems, with routine and exception reports. The parcelrecover from it. of transactional processing systems in Habisp refers to In real time, the data collected on the field, which the housing services part supported by this same systemincluded the perimeters of the areas analyzed, was (payment of benefits and issuing land ownershipentered into the Habisp system used the São Paulo regularization deeds for public areas). Nonetheless, oneCity Hall since 2006. of its most relevant components, the system to prioritize interventions, brings it closer or evenThe Habisp system qualifies it as a system that supports the decision making process, although this category so far does notHabisp is an information system that works through the have a broadly accepted definition.web, with the ability to store and process alphanumericand geographic information. The focus is popularhousing and the “loci” are the shanty towns, irregular
  3. 3. Proceedings of the Second World Landslide Forum – 3-7 October 2011, Rome with an extremely low compensation; consequently, this means scant opportunities to have access to the formal funding initiatives and their own housing. Furthermore, the real estate market in São Paulo has attained surreal levels of appreciation. The steep prices are mainly due to the scarcity of supply or land at compatible prices and locations. For those who are poor in São Paulo (families generally with incomes falling below three minimum wages), there are few opportunities, and those that exist at present arise precisely in precarious housing.Figure 1: Picture of the first page on the Habisp System.Source: Housing problem in the large urban centersHousing, in a very broad sense, is frequently deemed tobe key for the problem of poverty; a shanty town orslum is the environment of a poor man according to theoperational definition officially adopted at a UNmeeting in Nairobi, 2002. It is characterized by anexcess of population, precarious or informal housing, Figure 2: Picture of the Jaguaré Slum. Archives of theinadequate access to drinking water and sanitary Municipal Housing Secretariat – Sehab. City Hall of the Sãoconditions and insecurity as part of the ownership of Paulo Municipality.this house. Throughout the third world, the choice of housing What can be observed as a result of thisis a complicated calculation of ambiguous informality, is the greater occupation of areas that areconsiderations. Like the famous phrase of the anarchist subject to environmental restrictions, areas of risk witharchitect John Turner. “Housing is a verb”. The urban steep slopes or subject to flooding, contaminated soils,poor need to resolve a complex equation upon areas close to sanitary landfills or garbage deposits,attempting to optimize the cost of housing, guarantee among others, besides the concentration of a largeownership, the quality of the shelter, distance from number of social problems, especially those linked towork and oftentimes their own safety. And for all, the unsanitary conditions resulting from the absence ofworst situation is a poor and expensive area lacking in basic infrastructure, aggravated vis-à-vis thepublic services and without the warranty of ownership vulnerability of its inhabitants, caused by factors(DAVIS, 2006, p. 39). relating to informal employment, school abandonment In São Paulo, occupation in precarious settlements or drop outs, early pregnancy, domestic violence and- slums, irregular land plots or tenements – has been a drug trafficking.part of the urban scenery for quite some time (Figure 2). If, for the low income population, there are fewThe largest city in Latin America has one of the most alternatives and choosing becomes truly difficult, forcomplex housing problems in the country; and for public management, this problem is further aggravated,decades, facing up to this problem has posed a huge making intervention policies ever more complex. Tochallenge for those in government. Concern with the have an anchor for public policies, what is needed, inpoor, urban poverty and popular housing mixes old and the first place, is detailed knowledge of which are thenew ideas during each period of history, and successive problems that will be faced, in the quest to qualify andgenerations of reformists have struggled for the quantity the true needs. What does it mean toelimination of slums. The difficulties, in the field of understand each of these low-income occupations inhousing management, land market and funding for their totality, but also in terms of their specificities,housing for the low income population become evaluate the resources that are necessary to invest inaggravated day after day, thanks to the economic and each of the housing projects or programs, so as to selectsocial problems that exclude the less specialized those which will make it possible to optimize publicpopulation from labor markets, evermore demanding investment and attain the greater number of peopleand that offer – when they offer – informal employment possible among the destitute population. 3
  4. 4. E. Coelho, L. Pascarelli - Using the information system and multi-criteria analysis in the geological risk management in São Paulo For the Sehab, the intervention strategies were shanty towns, as in principle the program cannotclear, since work began to draft the MHP: urbanization regularize precarious situations, the focus shifted toand regularization of shanty towns and irregular land acting upon areas with the best indices (COELHO andplots occupied by low-income populations. However PÉREZ MACHADO, 2009).there existed the need to particularize that extensiveuniverse of settlements, to know where to truly begin Table 3: Precarious settlements in the city of São Paulo:each of the actions: that is to say, which slums to Conceptualization. Own draft. Altered by the CITY HALL OFurbanize in the coming years? In the coming month? THE MUNICIPALITY OF SÃO PAULO; ALLIANCE OF CITIES, 2008, p. 50.With resources available at present? Because of this it Informal occupations, self-built on the fringe ofwas necessary to have surveys and more concrete data, urban legislation, predominantly disorderly andbesides using analytical instruments with the ability to Favelas with a highly precarious infrastructure. Occupied byoffer more precise answers on where and how this low-income families that are social vulnerable.housing precariousness manifests itself. The Irregular occupations where the division of landgeographical aspect of the problem benefitted from the presents a layout that allows for the identificationuse of spatial analytical instruments of proven efficacy, of a plot in comparison to a route of access. These Irregularand it became necessary to build a model that could Settlements are done mainly on land that is predominantlyguide decision making, based on the existing data. privately owned and acquired through some sort of The path chosen was to set forth indicators that marketing and may encompass all of the familycould be evaluated individually and offer immediate income brackets. Multi-family collective housing made up of one orresponses, such as: degree of urbanization of a more buildings subdivided into several rooms.settlement, the population’s vulnerability, geological Tenements Sanitary facilities, circulation and precariousconditions etc., and that could be combined into a infrastructure, and generally overcrowded.single index. Through this procedure, the intention wasto attain a goal to set up a decision making model that The report “Characterization, Classification,would take into account the large diversity of variables Eligibility and Prioritization System for Interventions inthat existed in the context, and mainly the multiple Precarious Settlements in the Municipality of Sãoobjectives that had to be reached. Four stages were Paulo/ Brazil (2007)” highlights two principles set forthcreated to define the priority to service a specific for the selection of indicators and indices that jointlysettlement through a specific housing program: make up the prioritization index: (1) protection of thecharacterization, classification, eligibility and population’s life and the enhancement of livabilityprioritization, each with its own objective, as can be conditions to acceptable levels; and (2) protection of theobserved in Table 2. most vulnerable population socially. The same report points out that the first formulations carried out by theTable 2: Basic objectives of the phases proposed by theCharacterization, Classification, Eligibility and Prioritization Sehab divided the priorities stepwise into three levels:System. Own draft. (COELHO and PÉREZ MACHADO, 2009) high, medium and low, an approach that proved to be Characterization Classification Eligibility Priorization lacking, as the universe of settlements demands a much Characterize Classify these Select the Prioritize the larger scale, which led to the creation of a the areas into areas that activities in “prioritization index”, that attributes a score between 0 precarious groups that will undergo those areas and 1 to each settlement, being that 0 is the absence of settlements will guide the intervention, that fulfil the precariousness and 1 maximum precariousness based on in the type of already eligibility a multi-criteria analysis model. municipality intervention establishing criteria The prioritization index is a summarized index of São Paulo that is needed at this phase that aggregates other indices through a weighted a cut-off for the actions method. Habisp has a logical matrix where the weights are configured to calculate each of the indices that are part of the system, thus allowing the administrator to The first and foremost stage in the system is that interact with and validate the process, and also to adaptof characterization, as the results found in future stages it to any change in the situations that may have anwill be ramifications of the information collected impact on the decision making process. In Formula [1]:herein. Subsequently the work of updating the data (COELHO and PÉREZ MACHADO, 2009) we present abegan, as well as the conceptual definition of the types mathematical formula to calculate the prioritizationof settlements that would be serviced by the housing index for the urbanization program and for thepolicy, described in Table 3 below. precarious settlement regularization program. The principle adopted was simple: according to The indices used arise from several sources orthe objective of the action, the SEHAB defined the focus origins. Those of Health and Social Vulnerability wereof prioritization. For urbanization projects, the focus of appropriated by the Sehab from other initiatives, whichthe action was the most precarious areas in all of the means to say they were not produced exclusively for theissues analyzed. However, for the regularization of prioritization interventions, but serve as a benchmark
  5. 5. Proceedings of the Second World Landslide Forum – 3-7 October 2011, Romefor sectoral policies in health and social assistance, atthe municipal sphere. The Paulista Social VulnerabilityIndex (PSVI) bases itself on data from the 2000 IBGECensus and the Health Index is based on data from themunicipal health system for 2006. The urbanizationindex is calculated based on the data collected on thefield and inserted into Habisp, and updated wheneverthe field team identifies changes in the situationinformed; this falls entirely under Sehab´sresponsibility. Figure 3: Example of the overlay of the layer with the risk IP = [(Y – IF) x nf]+(IR x nr)+(IV x nv)+[(Y – IS) x ns] mapping (2010) and the shanty town layer. Santa Madalena (nf + nr + nv + ns) Park Slum. Source: [1]Being that: Being that:IF = urban infrastructure nf = weight of the urbanindex infrastructure indexIR = index for risks of bank nr = weight of the washout andwashouts and landslides landslide indexIV = social vulnerability index nv = weight of the socialIS = health index vulnerability index ns = weight of the health indexY = Priority Ordainment Factor. (of growing order = 1) (ifdecreasing order = 0) Figure 4: Example of the interface to update data on the riskTreatment of the landslide risk index in the sectors (2010). Source: system Considering that the geological risk is aThe risk of washouts and landslides is founded on determinant factor to grant that condition of livabilitysurvey carried out by the Foundation for Support to the to an area, the use of Habisp as an aid in the newUniversity of São Paulo (FUSP), through a partnership mapping has offered not only the possibility to create awith the Institute for Technological Research (IPT), consistent data base on the risks in the city , but hasunder the title of “Mapping the risks associated to also allowed for the speedy transfer of that knowledge.washouts and landslides in slope areas and washout of Nowadays, delimiting the areas surveyed and the mainbanks in streams in the shanty towns of the attributes that were part of the evaluation ismunicipality of São Paulo, 2003”, in which the Housing information that can be accessed by technicians, as wellSecretariat participated in indicating those areas that as managers of municipal administration. The locationshould be subject to analysis by the IPT team, along of the risk sectors and the degree of probability thatwith the technical people (geologists, engineers and there will be a landslide is also available to universities,architects) from the sub districts. research centers, non-government organizations The Risk Index for the precarious settlements (NGO´s) and other stakeholders of this issue, throughnevertheless was conceived in the context of the Habisp.prioritization system, and is calculated for eachsettlement by using overlay operations (Figures 3 and IR=(Prb x nrb)/100+(Prm x nrm)/100+(Pra x nra)/100+(Prma x nrma)/1004). The Habisp identifies, for each settlement, the nrma 2percentage of its area (m ) that lies within each risk area [2]and then, through a calculation formula [2], whichattributes a weight to each degree of risk, presenting the Being that: Being that:risk index for wash outs and landslides for the specific Prb = % low risk nrb = weight of low risk Prm = % medium risk nrm = weight of medium risksettlement. ra Pra = % high risk n = weight of high risk Prma = % very high risk nrma = weight of very high risk 5
  6. 6. E. Coelho, L. Pascarelli - Using the information system and multi-criteria analysis in the geological risk management in São Paulo The result of using HABISP can already be seenin the major of government programs in progress. Themain one is the Municipal Housing Plan which can beretrofitted quickly and the interventions, could bereordered according to the risk areas in order to includethe elimination of the most serious risks by 2016(including also the provision of financial resources forsuch actions). Although the elimination of risks only inthe year 2016 may seem an unpromising scenario, therecognition of this critical situation is optimisticbecause it drives the municipality in search of moreresources and appropriate technical solutions that allowshortening the schedule.ReferencesBRASIL. Ministério das Cidades / Instituto de Pesquisas Tecnológicas – IPT. Mapeamento de Riscos em Encostas e Margem de Rios. Carvalho, C.S.; Macedo, E.S.; Ogura, A.T. (org). Brasília: Ministério das Cidades; Instituto de Pesquisas Tecnológicas – IPT, 2007.COELHO, E. C. R. Sistema de Caracteização, Classificação Elegibilidade e Priorização de Intervenções em Assentamentos precários no município de São Paulo/ Brasil. Prefeitura do Município de São Paulo. São Paulo, p. 181. 2007. Disponível em: Per_Review_oficial.PDF. Acesso em: 20 Jan. 2011.COELHO, E. C. R.; PÉREZ MACHADO, R. P. O Sistema de Priorização do Habisp: um estudo de caso. 12 Encontro de geógrafos da América Latina. Montevidéo: [s.n.]. 2009. p. 15. Disponível em: Acesso em: 12 Mar. 2011.DAVIS, M. Planeta Favela. Tradução de Beatriz Medina. São Paulo: Boitempo, 2006. 272 p. ISBN 85-7559-087-I.NOGUEIRA, F. R. Gerenciamento de Riscos Ambientais Associados à Escorregamento: Contribuição às Políticas Municipais Para Áreas de Ocupação Subnormal. Rio Claro, São Paulo, 2002, 269 p. Tese (Doutorado em Geociências) – UNESP.IPT/SMSP. Análise e mapeamento de riscos associados a escorregamentos em áreas de encostas e solapamentos de margens de córregos em favelas do município de São Paulo. Laboratório de Riscos Ambientais (LARA/Cetae/IPT) e Assessoria Técnica de Obras e Serviços (ATOS/SMSP/PMSP), 2010PREFEITURA DO MUNICÍPIO DE SÃO PAULO; CITIES ALLIANCE. Habitação de interesse social em São Paulo: desafios e novos instrumentos de gestão. São Paulo: Janeiro Projetos Urbanos, 2008. 96 p.PREFEITURA DO MUNICÍPIO DE SÃO PAULO. Plano Municipal de Habitação PMH 2009-2024: documento para debate público. Disponível em: Acesso em: 06 Jun. 2011.UNESP/FUSP/IPT. Mapeamento de risco associado a áreas de encosta e margens de córregos nas favelas do Município de São Paulo (2003/2004)
  7. 7. Proceedings of the Second World Landslide Forum – 3-7 October 2011, Rome