O Índice de Segurança Hídrica do Brasil e o Semiárido Brasileiro: Desafios e Riscos Futuros

In the Brazilian semi-arid region, water scarcity is recurrent, aggravated by historical droughts and increased water demand. In the search to mitigate such effects, the study aims to elaborate a dimension for the Brazilian Water Security Index (ISH), representing the risk associated with anthropic interference and the drought phenomenon in the region. The methodology aims to add a fifth dimension to ISH, which considers the human, economic, ecosystem, and resilience dimensions. The aim is to improve the water security map planned for the year 2035, applied to the Upper Course Basin of the Paraíba River. The new dimension, called the Risk Dimension, uses a simulated land use and land cover product for 2035 and the Cumulative Drought Map. The results show the lack of information in some dimensions of the ISH, where several ottobacias have their ISH represented by only one dimension. In this context, the Risk Dimension added information based on the demand and supply of water, considering all areas of anthropic use and the drought conditions that plague the region, changing the ISH of several locations. Therefore, the work contributes to refine the concept of risk adopted in the elaboration of the ISH, mainly for regions of greater climatic and social vulnerability, such as the Brazilian Semiarid, where the risk transcends quantifications of water supply and demand and directly affects human, political development and economical of the population, impacting the human actions that take place in the region and, consequently, its water security.