Assessment of water security using conceptual, deterministic and stochastic frameworks

• Autor(a) principal: Rodrigues, Dulce Buchala Bicca
• Data de Publicação: 2014
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: http://www.teses.usp.br/teses/disponiveis/18/18138/tde-18122014-094354/
• topic: Análise de incertezas; Cantareira water supply system; Environmental flow requirement; Escassez hídrica; Hydrological modeling; Modelagem hidrológica; Política de recursos hídricos; Sistema Cantareira de abastecimento de água; Uncertainty analysis; Vazões ambientais; Vulnerabilidade hídrica; Water policy; Water scarcity; Water vulnerability

A comprehensive assessment of water security incorporates a range of water-related concepts, since water policy issues to specific technical aspects of hydrological conditions and their interactions with societal needs and ecosystem functioning. This doctoral thesis is organized into three chapters that address such range of water security-related topics, aiming to establish a conceptual baseline and propose deterministic and stochastic accounting frameworks for a river basin water security evaluation. Specific assumptions and research questions are defined in each chapter, and are related to the management of \'Cantareira water supply system\' (located in Southeastern Brazil), focusing on different scales and on its political and hydrological aspects as well. The first chapter acts as a conceptual baseline for water security assessment, by examining general aspects of the Brazilian water policy and water allocation system. This study contrasts Brazilian and American water management systems applied to water transfer projects, discussing experiences from the \'Cantareira system\' and Colorado river basin. A deterministic accounting framework is presented in the second chapter, which is based on management of blue and green water kinds (defined in accordance with hydrological processes and storage types), and demonstrates how a quantitative analysis of provisioning and use (abstraction and consumption) of both water kinds can be conducted. An agricultural basin (291 km²) within the Cantareira water supply system (located upstream of the Cachoeira reservoir) was used to illustrate this approach. The impact of blue and green water use on median water resources conditions is accounted by the scarcity indicator, while the vulnerability indicator considers the probability of low availability of water resources. In the third chapter quantifies and discusses the impacts of uncertainties on water security indicators (proposed in the chapter 2), based on a multi-model and resampling framework, that considers several uncertainty sources including those related to: i) observed streamflow data; ii) hydrological model structure; iii) residual analysis; iv) Environmental Flow Requirement methods; v) the definition of critical conditions for water provision; and vi) the critical demand imposed by human activities. Then, the uncertainty is propagated through different methodological arrangements applied to the same study basin of chapter 2. In brief, the first chapter indicates that both Brazilian and American water management system can potentially contribute to each other. In the second chapter, the Blue/Green water-based accounting framework reveal clear spatial and temporal patterns of water scarcity and vulnerability levels within the basin, thereby improving our understanding of how and where water-related threats to human and aquatic ecosystem security can arise (so called hot-spots). The third chapter provide a general method that can form basis for meaningful support to end-users facing water resource challenges by enabling them to incorporate a viable uncertainty analysis into a robust decision making process. Further investigation are proposed in each research step of this doctoral thesis.