Recentes catástrofes provocadas por eventos hidrológicos extremos ocorridos nas cidades brasileiras revelaram a fragilidade das atuais políticas empregadas no tratamento do problema das inundações. Freqüentemente, faltam recursos mesmo para as ações emergenciais, e as ações estruturais aplicadas muitas vezes consistem de medidas pontuais e paliativas que não promovem soluções definitivas no âmbito de bacia hidrográfica. O tratamento do problema de inundações de maneira orientada ao risco, em lugar da tradicional abordagem orientada a evento, é uma alternativa que propicia soluções mais eficientes e sustentáveis. A gestão do risco de desastres naturais compreende três níveis: antes, durante e após o evento extremo, com base em ações que visam à redução do risco por meio de suas três componentes: ameaça, vulnerabilidade e exposição. No contexto do desenvolvimento e fortalecimento econômico do Brasil, os seguros para desastres naturais têm papel importante como agentes de transferência do risco que possibilitam a recuperação econômica das áreas atingidas. Vencido o entrave inicial à implantação de seguros deste tipo no Brasil, que foi a abertura, em 2007, ao mercado ressegurador internacional, o desafio que se apresenta atualmente é o desenvolvimento de metodologias que possibilitem relacionar a magnitude do evento natural extremo com o prejuízo monetário correspondente e o prêmio de seguro que possibilite ressarcir as perdas contabilizadas, considerando cenários de longo prazo. O modelo de seguros proposto neste trabalho é baseado no princípio de seguro indexado, em que o pagamento de indenizações é vinculado a uma variável climática, no caso, a vazão máxima de cheia. Foram utilizadas ferramentas de modelagem e simulação hidráulico-hidrológica para gerar mapas de risco de inundação e quantificar os prejuízos correspondentes às cheias de diferentes probabilidades de ocorrência. Em seguida, foi simulado um modelo econômico de seguros para obter o prêmio ótimo capaz de ressarcir os prejuízos estimados, considerando diferentes cenários de longo prazo. Um estudo de caso ilustra a aplicação do método em uma bacia hidrográfica caracterizada por problemas recorrentes de inundação, dado o processo de expansão urbana que nela vem ocorrendo. Foram avaliadas faixas de cobertura em função dos períodos de retorno das cheias correspondentes. Os resultados mostraram que a metodologia é adequada à análise do comportamento do fundo de seguros. Resseguros podem ser requeridos para o tratamento de eventos de períodos de retorno muito extremos. / Recent disasters caused by extreme hydrological events, occurred in Brazilian cities, have exposed how fragile the current policies are to manage such situation. Often, a lack of resources is observed even for emergency actions, while structural actions commonly consist of palliative and punctual measures that do not promote real solutions considering the watershed sphere. To face the problem based on a risk-oriented approach instead of the traditional event-oriented approach represents an alternative that provides more efficient and sustainable solutions. Disaster risk management comprehends three time-oriented phases: before, during and after the extreme event, each phase focusing on the three risk\'s components: hazard, vulnerability and exposition. As Brazil\'s economy grows stronger and more stable, natural disaster insurance plays an important role as a risk transfer mechanism, promoting economic resilience in damaged areas. After the opening of the reinsurance\'s market in 2007, Brazil\'s challenge is to develop methodologies relating extreme events hazard with its corresponding damage and an insurance premium, in a way that the losses can be refunded in long term sceneries. The insurance model proposed in this work is based on the indexed insurance, where the refunds are linked to a weather variable - the maximum discharge. Hydrologic and hydraulic simulations were developed in order to generate risk maps and to quantify the damage related to floods with different return periods. Afterwards, a flood insurance model was simulated in order to obtain the optimal insurance premium sufficient to refund the expected damage for long term sceneries. A case study illustrates the method in a watershed where flood events are frequent due to urban occupation. The insurance coverage associated to each flood return period was examined and the results have shown that the methodology is suitable for the analysis of the flood insurance\'s behavior. Reinsurance may be required to deal with extreme events with high return periods.

El objetivo de este estudio ha sido desarrollar un modelo hidrológico en la plataforma WEAP, para conocer la cobertura hídrica del abastecimiento de agua de la ciudad de Lima en un escenario actual (2020), a corto plazo 2025, mediano plazo (2035) y largo plazo (2050). El modelo WEAP (Sistema de Evaluación y Planificación del Agua), ha sido calibrado y validado con los registros históricos de los ríos Rímac, Chillón y Lurín, los cuales cuentan con información del periodo 1965-2019. Actualmente, el abastecimiento de agua potable a la ciudad de Lima proviene principalmente del río Rímac, con un caudal promedio de 18,63 m3/s y en época de estiaje se complementa con la explotación de aguas subterráneas de los acuíferos Rímac, Lurín y Chillón. con un volumen de 287 MMC/año. Es importante indicar que los recursos hídricos del río Rímac se complementan con los aportes de los proyectos Macapomacocha I, III y IV que aportan un volumen de 243.5 MMC/año y los aportes del túnel Gratón son 158 MMC/año. De las simulaciones realizadas se concluye que actualmente existe un déficit hídrico de 182 MMC/año y una cobertura del 81,8%. / The objective of this study has been to develop a hydrological model in the WEAP platform, to know the water coverage of the water supply of the city of Lima in a current scenario (2020), in the short term 2025, medium term (2035) and long term term (2050). The WEAP (Water Assessment and Planning System) model has been calibrated and validated with the historical records of the Rímac, Chillón and Lurín rivers, which have information from the 1965-2019 period. Currently, the supply of drinking water to the city of Lima comes mainly from the Rímac River, with an average flow of 18.63 m3 / s and in the dry season it is complemented by the exploitation of groundwater from the Rímac, Lurín and Chillón Aquifers. with a volume of 287 MMC / year. It is important to indicate that the water resources of the Rímac River are complemented by the contributions of the Macapomacocha I, III and IV projects that contribute a volume of 243.5 MMC / year and the contributions of the Graton tunnel are 158 MMC / year. From the simulations carried out, it is concluded that there is currently a water deficit of 182 MMC / year and a coverage of 81.8%. / Tesis

Existing terrestrial carbon accounting models have mainly investigated atmosphere-vegetationsoil stocks and fluxes but have largely ignored the hydrological flux of organic carbon. It is generally assumed that biomass and soil carbon are the only relevant pools in a landscape ecosystem. However, recent findings have suggested that significant amounts of organic carbon can dissolve (dissolved organic carbon or DOC) or particulate (particulate organic carbon or POC) in water and enter the hydrological flux at the catchment scale. A significant quantity of total organic carbon (TOC) sequestered through photosynthesis may be exported from the landscape through the hydrological flux and stored in downstream stocks.¶ This thesis presents a catchment-scale case study investigation into the export of organic carbon through a river system in comparison with carbon that is produced by vegetation through photosynthesis. The Cotter River Catchment was selected as the case study. It is a forested catchment that experienced a major wildfire event in January 2003. The approach is based on an integration of a number of models. The main input data were time series of in-stream carbon measurements and remotely sensed vegetation greenness. The application of models to investigate diffuse chemical substances has dramatically increased in the past few years because of the significant role of hydrology in controlling ecosystem exchange. The research firstly discusses the use of a hydrological simulation model (IHACRES) to analyse organic carbon samples from stream and tributaries in the Cotter River Catchment case study. The IHACRES rainfall-runoff model and a regionalization method are used to estimate stream-flow for the 75 sub-catchments. The simulated streamflow data were used to calculate organic carbon loads from concentrations sampled at five locations in the catchment.¶ The gross primary productivity (GPP) of the vegetation cover in the catchment was estimated using a radiation use efficiency (RUE) model driven by MODIS TERRA data on vegetation greenness and modeled surface irradiance (RS). The relationship between total organic carbon discharged in-stream and total carbon uptake by plants was assessed using a cross-correlation analysis.¶ The IHACRES rainfall-runoff model was successfully calibrated at three gauged sites and performed well. The results of the calibration procedure were used in the regionalization method that enabled streamflow to be estimated at ungauged locations including the seven sampling sites and the 75 sub-catchment areas. The IHACRES modelling approach was found appropriate for investigating a wide range of issues related to the hydrological export of organic carbon at the catchment scale. A weekly sampling program was implemented to provide estimates of TOC, DOC and POC concentrations in the Cotter River Catchment between July 2003 and June 2004. The organic carbon load was estimated using an averaging method.¶ The rate of photosynthesis by vegetation (GPP) was successfully estimated using the radiation use efficiency model to discern general patterns of vegetation productivity at sub-catchment scales. This analysis required detailed spatial resolution of the GPP across the entire catchment area (comprising 75 sub-catchment areas) in addition to the sampling locations. Important factors that varied at the catchment scale during the sampling period July 2003 – June 2004, particularly the wildfire impacts, were also considered in this assessment. ¶ The results of the hydrologic modelling approach and terrestrial GPP outcome were compared using cross correlation and regression analysis. This comparison revealed the likely proportion of catchment GPP that contributes to in-stream hydrological flux of organic carbon. TOC Load was 0.45% of GPP and 22.5 - 25% of litter layer. As a result of this investigation and giving due consideration to the uncertainties in the approach, it can be concluded that the hydrological flux of organic carbon in a forested catchment is a function of gross primary productivity.