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In this thesis, topics in chemical hazard and risk assessment are explored through the use of multimedia mass balance models and high-throughput chemical property prediction methods. Chemical hazard metrics, as calculated by environmental fate and transport simulations, are investigated to determine the validity of two common simplifying assumptions in the underlying models; the use of octanol as a surrogate for organic matter and the use of environmental parameters that do not vary in time. A major finding is that the use of these common simplifying assumptions in multimedia mass balance models has little effect on chemical risk assessment, provided that chemicals are ranked relative to each other rather than a predetermined cutoff value. Chemical properties relevant to hazard and risk are collected, and applied in a large-scale chemical hazard assessment to derive a short list of potential Arctic contaminants. Several further data needs are identified; these are widely applicable and easily calculable metrics for chemical biodegradation, toxicity and emissions. A new method of predicting chemical properties is presented to assist in meeting these data needs. The method automatically creates predictive, quantitative relationships between the structures and properties of chemicals that are comparable to similar relationships created with expert judgement.

In this thesis, topics in chemical hazard and risk assessment are explored through the use of multimedia mass balance models and high-throughput chemical property prediction methods. Chemical hazard metrics, as calculated by environmental fate and transport simulations, are investigated to determine the validity of two common simplifying assumptions in the underlying models; the use of octanol as a surrogate for organic matter and the use of environmental parameters that do not vary in time. A major finding is that the use of these common simplifying assumptions in multimedia mass balance models has little effect on chemical risk assessment, provided that chemicals are ranked relative to each other rather than a predetermined cutoff value. Chemical properties relevant to hazard and risk are collected, and applied in a large-scale chemical hazard assessment to derive a short list of potential Arctic contaminants. Several further data needs are identified; these are widely applicable and easily calculable metrics for chemical biodegradation, toxicity and emissions. A new method of predicting chemical properties is presented to assist in meeting these data needs. The method automatically creates predictive, quantitative relationships between the structures and properties of chemicals that are comparable to similar relationships created with expert judgement.

ENVIRONMENTAL MODELLING OF LAND USE CHANGES IN THE NEIGHBOURHOOD OF COAL MINES WITH THE GIS Abstract Human society causes an increasing pressure on land and its use. The requirements and demands of humanity has significantly changed in the last few decades. This is the foundation of continuous environmental impacts, particularly in those areas where mining companies exploit natural resources on a large scale for personal and economic well-being, and thus significantly transform the land surface. The objective of this thesis is to refer to changes in land use in the vicinity of surface coal mines in the districts of Chomutov, Most, Teplice and Sokolov where these coal mines take up large areas. We do so with the help of remote-sensing-based documentation and GIS applications. Mining dramatically transforms the appearance of surrounding landscapes and has a high impact on the environment. The thesis shows the change of land use based on both the images from the Landsat satellite and the inclusion in basic Corine categories in which was created layer of land cover for 1990, 2000, 2006 and 2012, and further shows the ecological stability of the landscape from 1986 up to now. The evolution and changes of ecological stability are analyzed with the help of ecological coefficient, cluster analysis, linear...

Scientific datasets from global-scale scientific models and remote sensing instruments are becoming available at greater spatial and temporal resolutions with shorter lag times. These data are frequently gridded measurements spanning two or three spatial dimensions, the time dimension, and often several data dimensions which vary by the specific dataset. These data are useful in many modeling and analysis applications across the geosciences. Unlike vector spatial datasets, raster spatial datasets lack widely adopted conventions in file formats, data organization, and dissemination mechanisms. Raster datasets are often saved using the Network Common Data Format (NetCDF), Gridded Binary (GRIB), Hierarchical Data Format (HDF), or Geographic Tagged Image File Format (GeoTIFF) file formats. Several of these are entirely or partially incompatible with common GIS software which introduces additional complexity in extracting values from these datasets. We present a method and companion Python package as a general-purpose tool for extracting time series subsets from these files using various spatial geometries. This method and tool enable efficient access to multidimensional data regardless of the format of the data. This research builds on existing file formats and software rather than suggesting new alternatives. We also present an analysis of optimizations and performance.

Revegetation is required to conserve the biological diversity of over-cleared and fragmented agricultural regions. This dissertation represents an application of spatial information technologies to environmental management. It makes a significant contribution to the integration of general landscape-scale principles into restoration ecology. New and established quantitative, spatial analytical techniques are used in environmental modelling, ecological assessment and in setting geographic priorities for strategic revegetation planning in the Mt. Lofty Ranges in South Australia. This is one of the first assessments of the adequacy and representativeness of remnants in an agricultural region and one of the first attempts to apply these landscape-scale conservation principles to the field of restoration ecology. The adequacy of the remnant ecological system is assessed in terms of the landscape structure. Landscape ecological principles provide a basis for setting geographic priorities for the revegetation of an adequate remnant ecological system. Although seldom quantified, it is often thought that remnants in agricultural regions are not representative of the regional physical environmental heterogeneity. The representativeness of remnant vegetation is assessed in the study area and a complex effect of land clearance and reserve selection on representativeness is revealed which has significant implications for strategic revegetation planning. Land clearance has precluded the use of information on the spatial distribution of biological diversity in agricultural regions. Hence, a surrogate is required in strategic planning for the restoration of a representative regional ecological system. The degree of vegetation/environment convergence is assessed to investigate the viability of using the physical environment as a surrogate for the distribution of biological diversity. An index of coincidence is developed specifically for this purpose. An environmental classification is then derived for use in setting geographic priorities for the restoration of a representative regional ecological system. Three complementary techniques are used to find the simplest classification possible that does not have overly broad environmental classes. Geographic priorities are suggested according to the distribution and representativeness of environment types in the study area. In the light of the results of this dissertation, a research direction for restoration ecology in agricultural landscapes is mapped out. / Thesis (Ph.D.)--Department of Geographical and Environmental Studies; Department of Applied and Molecular Ecology, 2000.

Real-world problems, especially those that involve natural systems, are complex and composed of many nondeterministic components having non-linear coupling. It turns out that in dealing with such systems, one has to face a high degree of uncertainty and tolerate imprecision. Classical system models based on numerical analysis, crisp logic or binary logic have characteristics of precision and categoricity and classified as hard computing approach. In contrast soft computing approaches like probabilistic reasoning, fuzzy logic, artificial neural nets etc have characteristics of approximation and dispositionality. Although in hard computing, imprecision and uncertainty are undesirable properties, in soft computing the tolerance for imprecision and uncertainty is exploited to achieve tractability, lower cost of computation, effective communication and high Machine Intelligence Quotient (MIQ). Proposed thesis has tried to explore use of different soft computing approaches to handle uncertainty in environmental risk management. The work has been divided into three parts consisting five papers. In the first part of this thesis different uncertainty propagation methods have been investigated. The first methodology is generalized fuzzy α-cut based on the concept of transformation method. A case study of uncertainty analysis of pollutant transport in the subsurface has been used to show the utility of this approach. This approach shows superiority over conventional methods of uncertainty modelling. A Second method is proposed to manage uncertainty and variability together in risk models. The new hybrid approach combining probabilistic and fuzzy set theory is called Fuzzy Latin Hypercube Sampling (FLHS). An important property of this method is its ability to separate randomness and imprecision to increase the quality of information. A fuzzified statistical summary of the model results gives indices of sensitivity and uncertainty that relate the effects of variability and uncertainty of input variables to model predictions. The feasibility of the method is validated to analyze total variance in the calculation of incremental lifetime risks due to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) for the residents living in the surroundings of a municipal solid waste incinerator (MSWI) in Basque Country, Spain. The second part of this thesis deals with the use of artificial intelligence technique for generating environmental indices. The first paper focused on the development of a Hazzard Index (HI) using persistence, bioaccumulation and toxicity properties of a large number of organic and inorganic pollutants. For deriving this index, Self-Organizing Maps (SOM) has been used which provided a hazard ranking for each compound. Subsequently, an Integral Risk Index was developed taking into account the HI and the concentrations of all pollutants in soil samples collected in the target area. Finally, a risk map was elaborated by representing the spatial distribution of the Integral Risk Index with a Geographic Information System (GIS). The second paper is an improvement of the first work. New approach called Neuro-Probabilistic HI was developed by combining SOM and Monte-Carlo analysis. It considers uncertainty associated with contaminants characteristic values. This new index seems to be an adequate tool to be taken into account in risk assessment processes. In both study, the methods have been validated through its implementation in the industrial chemical / petrochemical area of Tarragona. The third part of this thesis deals with decision-making framework for environmental risk management. In this study, an integrated fuzzy relation analysis (IFRA) model is proposed for risk assessment involving multiple criteria. The fuzzy risk-analysis model is proposed to comprehensively evaluate all risks associated with contaminated systems resulting from more than one toxic chemical. The model is an integrated view on uncertainty techniques based on multi-valued mappings, fuzzy relations and fuzzy analytical hierarchical process. Integration of system simulation and risk analysis using fuzzy approach allowed to incorporate system modelling uncertainty and subjective risk criteria. In this study, it has been shown that a broad integration of fuzzy system simulation and fuzzy risk analysis is possible. In conclusion, this study has broadly demonstrated the usefulness of soft computing approaches in environmental risk analysis. The proposed methods could significantly advance practice of risk analysis by effectively addressing critical issues of uncertainty propagation problem. / Los problemas del mundo real, especialmente aquellos que implican sistemas naturales, son complejos y se componen de muchos componentes indeterminados, que muestran en muchos casos una relación no lineal. Los modelos convencionales basados en técnicas analíticas que se utilizan actualmente para conocer y predecir el comportamiento de dichos sistemas pueden ser muy complicados e inflexibles cuando se quiere hacer frente a la imprecisión y la complejidad del sistema en un mundo real. El tratamiento de dichos sistemas, supone el enfrentarse a un elevado nivel de incertidumbre así como considerar la imprecisión. Los modelos clásicos basados en análisis numéricos, lógica de valores exactos o binarios, se caracterizan por su precisión y categorización y son clasificados como una aproximación al hard computing. Por el contrario, el soft computing tal como la lógica de razonamiento probabilístico, las redes neuronales artificiales, etc., tienen la característica de aproximación y disponibilidad. Aunque en la hard computing, la imprecisión y la incertidumbre son propiedades no deseadas, en el soft computing la tolerancia en la imprecisión y la incerteza se aprovechan para alcanzar tratabilidad, bajos costes de computación, una comunicación efectiva y un elevado Machine Intelligence Quotient (MIQ). La tesis propuesta intenta explorar el uso de las diferentes aproximaciones en la informática blanda para manipular la incertidumbre en la gestión del riesgo medioambiental. El trabajo se ha dividido en tres secciones que forman parte de cinco artículos. En la primera parte de esta tesis, se han investigado diferentes métodos de propagación de la incertidumbre. El primer método es el generalizado fuzzy α-cut, el cual está basada en el método de transformación. Para demostrar la utilidad de esta aproximación, se ha utilizado un caso de estudio de análisis de incertidumbre en el transporte de la contaminación en suelo. Esta aproximación muestra una superioridad frente a los métodos convencionales de modelación de la incertidumbre. La segunda metodología propuesta trabaja conjuntamente la variabilidad y la incertidumbre en los modelos de evaluación de riesgo. Para ello, se ha elaborado una nueva aproximación híbrida denominada Fuzzy Latin Hypercube Sampling (FLHS), que combina los conjuntos de la teoría de probabilidad con la teoría de los conjuntos difusos. Una propiedad importante de esta teoría es su capacidad para separarse los aleatoriedad y imprecisión, lo que supone la obtención de una mayor calidad de la información. El resumen estadístico fuzzificado de los resultados del modelo generan índices de sensitividad e incertidumbre que relacionan los efectos de la variabilidad e incertidumbre de los parámetros de modelo con las predicciones de los modelos. La viabilidad del método se llevó a cabo mediante la aplicación de un caso a estudio donde se analizó la varianza total en la cálculo del incremento del riesgo sobre el tiempo de vida de los habitantes que habitan en los alrededores de una incineradora de residuos sólidos urbanos en Tarragona, España, debido a las emisiones de dioxinas y furanos (PCDD/Fs). La segunda parte de la tesis consistió en la utilización de las técnicas de la inteligencia artificial para la generación de índices medioambientales. En el primer artículo se desarrolló un Índice de Peligrosidad a partir de los valores de persistencia, bioacumulación y toxicidad de un elevado número de contaminantes orgánicos e inorgánicos. Para su elaboración, se utilizaron los Mapas de Auto-Organizativos (SOM), que proporcionaron un ranking de peligrosidad para cada compuesto. A continuación, se elaboró un Índice de Riesgo Integral teniendo en cuenta el Índice de peligrosidad y las concentraciones de cada uno de los contaminantes en las muestras de suelo recogidas en la zona de estudio. Finalmente, se elaboró un mapa de la distribución espacial del Índice de Riesgo Integral mediante la representación en un Sistema de Información Geográfico (SIG). El segundo artículo es un mejoramiento del primer trabajo. En este estudio, se creó un método híbrido de los Mapas Auto-organizativos con los métodos probabilísticos, obteniéndose de esta forma un Índice de Riesgo Integrado. Mediante la combinación de SOM y el análisis de Monte-Carlo se desarrolló una nueva aproximación llamada Índice de Peligrosidad Neuro-Probabilística. Este nuevo índice es una herramienta adecuada para ser utilizada en los procesos de análisis. En ambos artículos, la viabilidad de los métodos han sido validados a través de su aplicación en el área de la industria química y petroquímica de Tarragona (Cataluña, España). El tercer apartado de esta tesis está enfocado en la elaboración de una estructura metodológica de un sistema de ayuda en la toma de decisiones para la gestión del riesgo medioambiental. En este estudio, se presenta un modelo integrado de análisis de fuzzy (IFRA) para la evaluación del riesgo cuyo resultado depende de múltiples criterios. El modelo es una visión integrada de las técnicas de incertidumbre basadas en diseños de valoraciones múltiples, relaciones fuzzy y procesos analíticos jerárquicos inciertos. La integración de la simulación del sistema y el análisis del riesgo utilizando aproximaciones inciertas permitieron incorporar la incertidumbre procedente del modelo junto con la incertidumbre procedente de la subjetividad de los criterios. En este estudio, se ha demostrado que es posible crear una amplia integración entre la simulación de un sistema incierto y de un análisis de riesgo incierto. En conclusión, este trabajo demuestra ampliamente la utilidad de aproximación Soft Computing en el análisis de riesgos ambientales. Los métodos propuestos podría avanzar significativamente la práctica de análisis de riesgos de abordar eficazmente el problema de propagación de incertidumbre.

The present work consisted on the characterization of the spatial distribution of hydraulic parameters on the Almádena-Odeáxere aquifer system (AO) using the automatic calibration of a finite-element numeric model, in order to improve the simulation accuracy of the aquifer’s hydraulic behaviour. This development has its foundations based on model variants already implemented at the University of Algarve to investigate the hydraulic properties of the AO on the framework of the regional scale groundwater flow studies concerning Algarve aquifers. The state-of-the-art of the aquifer’s hydrogeology was based on previous investigations, taking place on the last years in Algarve, but also on recent fieldwork, namely on the collection of field data from a monitoring network, designed in articulation with the “POCTI/AMB/57432/2004” investigation project, which provided the feedback information needed for the improvement of model variants developed during the course of the present work. Instead of using a classic, time consuming, trial and error approach for the purpose of determining hydraulic parameters controlling groundwater flow at AO, an automatic inverse calibration algorithm was used, allowing the achievement of parameter distribution values capable of generating realistic hydraulic flow simulations. The Gauss-Marquardt-Levenberg method of nonlinear parameter estimation, available at the PEST algorithm was assembled to the finite element flow model, which is based in the use of the Galerkin method of weighted residuals. The results obtained by the use of the inverse method have revealed a good fit between simulated and measured head values, since the correlation coefficient, R, value was higher than 0,9 (0,9967) and the sum-of-squared weighted residuals between model outcomes and corresponding field data (i.e. the objective function, F) was only 4,56 m. The obtained spatial distribution of transmissivity, ranging from 86 m2/day to 8158 m2/day on 16 zones, allowed a step further on the reliability of future simulations of spatial distribution and temporal evolution of state variables in natural conditions and considering different scenarios of water use.

Submitted by Dener Toledo Mathias (denertm@yahoo.com.br) on 2016-03-30T19:09:05Z No. of bitstreams: 1 Tese - Dener Toledo Mathias.pdf: 16459329 bytes, checksum: e3ee47ea570a4c41bb6897a23913c1f9 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-01T19:57:54Z (GMT) No. of bitstreams: 1 mathias_dt_dr_prud.pdf: 16459329 bytes, checksum: e3ee47ea570a4c41bb6897a23913c1f9 (MD5) / Made available in DSpace on 2016-04-01T19:57:54Z (GMT). No. of bitstreams: 1 mathias_dt_dr_prud.pdf: 16459329 bytes, checksum: e3ee47ea570a4c41bb6897a23913c1f9 (MD5) Previous issue date: 2016-02-15 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A ocorrência de processos erosivos lineares em cabeceiras de drenagem no contato com áreas urbanas constitui um fenômeno que, por resultar em impactos negativos sobre o meio físico e oferecer uma situação de risco à população, exige a adoção de medidas mitigadoras. Tais áreas, caracteristicamente antropizadas, exibem dinâmica processual geomorfológica complexa, marcada pela interação entre feições erosivas e morfologias tecnogênicas. A partir dessas premissas, o presente trabalho objetiva apresentar uma contribuição metodológica aplicável ao estudo dos processos erosivos ocorrentes em áreas periurbanas, visando o diagnóstico atual e a identificação das tendências evolutivas. Foi escolhido como estudo de caso um setor na periferia urbana do município de São Pedro (SP), delimitado pela alta bacia do córrego Tucum, área caracterizada por conter formas erosivas lineares e paisagem marcada por intensas intervenções. A pesquisa se fundamentou na Teoria Geral dos Sistemas aplicada à Geografia, e as técnicas empregadas envolveram a quantificação de variáveis hidrogeomorfológicas e tecnogênicas. Os dados foram obtidos experimentalmente em campo e submetidos ao tratamento em ambiente SIG, permitindo uma análise integrada dos atributos físicos. Os resultados corroboram que técnicas experimentais específicas no âmbito da geomorfologia podem ser aplicadas no contexto de áreas antropicamente perturbadas, fornecendo aporte ao entendimento da dinâmica processual. O diagnóstico gerado aponta que os processos na área encontram-se ativos e o prognóstico indica setores com maior tendência ao avanço erosivo linear, contribuindo com subsídios importantes à projetos de recuperação. / The occurrence of linear erosion in headwaters in contact with urban areas is a phenomenon that result in negative impacts on the physical environment and provide a population to risk, requires the adoption of mitigation actions. This areas exhibit a complex geomorphological dynamic process marked by interaction between erosive features and technogenic morphologies. Therefore, this work presents a methodological contribution applicable to the study of erosion in periurban areas, aiming at the current diagnosis, and identification of evolutionary trends. It was chosen as a case study a sector in the urban periphery of São Pedro (SP) delimited by the upper basin of the Tucum stream, area characterized by containing linear erosive forms and landscape marked by intense interventions. The research is based on General Systems Theory applied to Geography and the techniques employed was the quantification of hydrogeomorphological and tecnogenic variables. The data were obtained experimentally in the field and subjected to treatment in a GIS environment, allowing an integrated analysis of physical attributes. The results support that specific experimental techniques within the geomorphology can be applied in the context of anthropically disturbed areas, providing understanding of the dynamic of process. The diagnosis generated shows that the processes in the area are active and prognosis indicates sectors most prone to the erosion linear advancement, contributing with subsidies to recovery projects. / FAPESP: 2012/03745-4

Questões ambientais e sócio-econômicas nem sempre coexistem de forma conciliada, o que pode opor a conservação da biodiversidade, a regulação climática, a produção e qua¬li¬da¬de da água, com outros fatores como a produção de energia, alimentos e fibras, e a geração de empregos. No Brasil, o código florestal prescreve as Áreas de Preservação Permanente como forma de garantir a manutenção dos Serviços Ambientais (SA), e os projetos de Pagamento de Serviços Ambientais (PSA) estão surgindo como forma de recompensar os provedores de SA, como o Projeto Conservador das Águas, a primeira experiência municipal brasileira, em andamento no Município de Extrema, MG. Apesar dos esforços, ainda são escassos os estudos que quantifiquem os benefícios econômicos dos serviços ambientais, fundamental para que estes sejam incluídos nas tomadas de decisões. O objetivo do trabalho foi quantificar e valorar os Serviços Ambientais hidrológicos da recuperação da vegetação, na sub-bacia do Ribeirão das Posses, em Extrema, através da modelagem ambiental. Utilizando o modelo InVEST (Integrated Valuation of Environmental Services and Tradeoffs) foram simuladas a vazão e o fluxo de sedimentos em um cenário anterior e posterior ao Projeto Conservador das Águas, um cenário sem práticas de conservação (Antropizado), e em cenários que priorizassem o reflorestamento ao longo das margens dos rios (reflorestamento ripário) ou nas encostas (reflorestamento das áreas íngremes). Os Serviços Ambientais foram estimados a partir do custo evitado da redução do tratamento de água e dragagem (custos off-site) e na erosão (custos on-site), em função da diferença entre os cenários, e foram comparados com o Pagamento por Serviços Ambientais e o custo de oportunidade, equivalente aos rendimentos da pecuária extensiva. Verificou-se que as estradas geraram 29% da perda de solos na sub-bacia, e as barraginhas, uma das práticas conservacionistas adotadas pelo projeto, diminuíram em 4% os sedimentos na foz da sub-bacia, e o reflorestamento de espécies nativas em 5%. Juntas, as duas práticas contribuíram para 9% de redução. A redução do fluxo de sedimentos do Pós-Projeto em relação ao cenário Antropizado foi de 40%. O reflorestamento ripário foi mais eficiente na redução de fluxo de sedimentos do que o reflorestamento das áreas íngremes e gerou maior redução nos custos de tratamento de água e de dragagem. Enquanto um reflorestamento ripário de apenas 5 m reduziu em 23% o fluxo de sedimentos, um reflorestamento nas áreas íngremes com a mesma área de floresta (áreas com declividade acima de 60%) reduziu o fluxo de sedimentos em 2%. Para um reflorestamento ripário de 30 m, o mesmo foi reduzido em 50%. Por outro lado, o reflorestamento das áreas íngremes foi mais eficiente na redução da perda de solos, e portanto, obteve maior redução dos custos on-site, pela redução dos prejuízos causados pela erosão. Os resultados mostram a importância de projetos como o Conservador das Águas, não só na melhoria das condições ambientais, mas principalmente na conservação de florestas nativas. Os pequenos agricultores são uns dos principais beneficiários devido à melhoria das condições sociais e ambientais, embora não sejam os únicos, uma vez que os benefícios vão além dos limites da sub-bacia, e acreditamos que os esforços para a preservação devem ser com¬par¬ti¬lha-dos pelos beneficiários indiretos, que no caso da sub-bacia do Ribeirão das Posses, seriam os usuários da água do Sistema Cantareira. A nossa sugestão para esta contribuição é de pelo menos 28% do Pagamento por Serviços Ambientais por área preservada. / Environmental and socioeconomic issues not always coexist in a reconciled manner, which may oppose biodiversity conservation, climate regulation, water quality and production, to other factors such as energy production, food and fiber, and job creation. In Brazil, the Forest Code prescribes the Permanent Preservation Areas in order to guarantee the maintenance of Environmental Services (ES), and the Payment for Environmental Services project (PES) are emerging as a way to reward the providers of ES, as Conservador das Águas project, the first Brazilian municipal initiative, underway in Extrema Municipality. Despite the efforts, there are few studies that quantify the economic benefits of ecosystem services essential for them to be part of decision-making process. The objective of this work was to quantify and assess the hydrological Environmental Services in the recovery of vegetation in Posses subbasin in Extrema, through environmental modeling. Using InVEST model (Integrated Valuation of Environmental Services and Tradeoffs) we simulated sediment and streamflow in a scenario before Conservador das Águas project (Pre-Project), after (Post-Project), another with no soil conservation practices (Anthropized), and others which prioritize reforestation of riparian areas (riparian reforestation) or in slopes (reforestation of steep areas). The Environmental Services were estimated based on the avoided cost of reducing water treatment and dredging (off-site costs) and erosion (on-site costs), as functions of the difference between scenarios, and they were compared to the Payment for Environmental Services and the opportunity cost, equivalent to the extensive livestock income. It was found that the roads contributed to 29% of the total soil loss in the subbasin, and barraginhas, one of the conservation practices adopted by the project, decreased sediment flow in the river mouth by 4%, and reforestation of native species by 5%. Together, the two practices contributed to a reduction in 9%. The reduction of sediments flow in Post-Project scenario in relation to Anthropized was of 40%. Riparian reforestation was more efficient in the reduction of sediment flow than the reforestation of steep areas, what caused greater reduction in the costs of water treatment and dredging. While a 5 m riparian reforestation reduced sediment flow by 23%, reforestation in steep areas with the same area of forest (areas with slope above 60%) reduced sediment flow by 2%. For a 30 m of riparian strip of reforestation, it was reduced by 50%. On the other hand, reforestation of steep areas was more efficient in reducing soil loss, and so it presented greater reduction in on-site costs by reducing the losses caused by erosion. Results showed the importance of projects such as the Conservador das Águas, not only in the improvement of environmental conditions, but mainly in the conservation of native forests. The main beneficiaries of these projects are small farmers by improving social and environmental conditions, but the benefits go beyond the subbasin boundaries, and we believe that efforts to preserve must be shared by indirect beneficiaries, which in the case of Posses subbasin are the users of water from the Cantareira System. Our suggestion for this contribution is at least 28% of Payment for Environmental Services by preserved area.