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Orientadora: Prof. Dra. María Cleofé Valverde Brambila Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, Santo André, 2020. As alterações do clima e mudança do regime das chuvas podem tornar os recursos hídricos de uma bacia hidrográfica vulneráveis à escassez de água. Este trabalho tem como objetivo identificar a vulnerabilidade atual e futura dos recursos hídricos da bacia do rio Ribeira de Iguape (BHRRI) frente às mudanças climáticas, considerando os fatores socioambientais para as três sub-bacias mais importantes em relação ao uso da água: Alto Juquiá, Baixo Ribeira e Rio Ribeira de Iguape. O método baseou-se num Índice de Vulnerabilidade Geral atual (IVG) através da agregação do Índice de Vulnerabilidade Social (IVS), formado por componentes socioeconômicas da região e Ambiental (IVA), composto por tipo de uso do solo e Hidroclimático (IVH) gerado por índices extremos de chuva e disponibilidade hídrica. Já o IVG futuro (IVGF) foi calculado com os mesmos IVA e IVS atuais, somando-se ao IVH futuro (IVHF), onde os indicadores foram resultados das projeções futuras do modelo climático Eta-HadGEM2-ES em dois cenários de emissões, 4,5 e 8,5 RCP, e em 3 time slices que se dividem nos periodos de 2006-2040 (time slice 1), 2041-2070 (time slice 2) e de 2071 a 2099 (time slice 3). Os resultados mostraram que para o contexto atual, o IVG classificou a Alto Juquiá como de alta vulnerabilidade, devido ao IVH apresentar a menor disponibilidade hídrica e uma tendência negativa de índices climáticos de chuva (PRCPTOT, CWD, Rx5day, R10mm, R20mm e R25mm). Tanto no IVG atual como no futuro as sub-bacias apresentaram vulnerabilidade média, no entanto somente em Alto Juquiá o IVG atual é maior que o IVGF. No cenário de 8,5 RCP, o IVGF esteve na classificação de média vulnerabilidade, porém o IVHF apresentou vulnerabilidade alta para o time slice 1 e 2, na bacia do Alto Juquiá. Ressalta-se também que as projeções futuras da disponibilidade hídrica para todos os cenários foram de aumento em quase todas as sub-bacias, apenas em Baixo Ribeira e Alto Juquiá mostraram diminuição no time slice 3. Alto Juquiá, que fornece água para a Região Metropolitana de São Paulo, mostrou ter boa situação com a disponibilidade de água, segundo as simulações do Eta-HadGEM2-ES, mesmo considerando os cenários de transposição de até 9,65 m3/s, conforme abordado no último plano da BHRRI. Estudos referentes aos recursos hídricos da BHRRI são importantes para o gerenciamento da própria bacia hidrográfica, a fim de compreender os fatores que influenciam na disponibilidade de água em meio às mudanças climáticas, bem como desvendar se o abastecimento de água de bacias vizinhas, como a bacia do Alto Tietê, pode contribuir para escassez hídrica ao considerar as projeções futuras do clima. Climate change and changes in the rainfall regime can make the water resources of a watershed vulnerable to water scarcity. This work aims to identify the current and future vulnerability of water resources in the Ribeira de Iguape River Basin (BHRRI) in the face of climate change, considering socioenvironmental factors for the three most important sub-basins regarding to water use: Alto Juquiá, Baixo Ribeira and Rio Ribeira de Iguape. The method was based on a current General Vulnerability Index (IVG) through the aggregation of the Social Vulnerability Index (IVS), formed by socioeconomic components of the region, Environmental (IVA), composed by type of land use, and Hydroclimate (IVH), generated by extreme rain index and water availability. The future IVG (IVGF) was calculated using the same current IVA and IVS, adding to the future IVH (IVHF), where the indicators were the result of future projections of the Eta-HadGEM2-ES climate model in two emission scenarios RCP 4.5 and RCP 8.5, and into three time slices that were divided into the periods of 2006-2040 (time slice 1), 2041-2070 (time slice 2) and from 2071 to 2099 (time slice 3). The results showed that for the current context, the IVG classified Alto Juquiá as highly vulnerable, due to the fact that the IVH has the lowest water availability and a negative trend in climatic rainfall indexes (PRCPTOT, CWD, Rx5day, R10mm, R20mm and R25mm). Both the current IVG and the sub-basins in the future showed average vulnerability, however only in Alto Juquiá the current IVG is greater than the IVGF. In the RCP 8.5 scenario, the IVGF was classified as medium vulnerability, but the IVHF showed high vulnerability for time slice 1 and 2, in the Alto Juquiá basin. It is also noteworthy that the future projections of water availability for all scenarios increased in almost all sub-basins, only in Baixo Ribeira and Alto Juquiá showed a decrease in time slice 3. Alto Juquiá, which supplies water to the Metropolitan Region of São Paulo, revealed a good situation regarding the availability of water, according to the simulations of Eta-HadGEM2-ES, even considering the inter-basin water transfer scenarios of up to 9.65 m3/s, as discussed in the last BHRRI plan. Studies referring to BHRRI's water resources are important for the management of the watershed itself, in order to understand the factors that influence the availability of water amid climate change, as well as to unveil whether the water supply to neighboring basins, such as the basin Alto Tietê, can contribute to water scarcity when considering future climate projections.

Trends in indices of precipitation extremes are studied on the basis of daily precipitation measurements from five meteorological stations in Croatia covering different climate regions: Osijek in the very southern part of the Pannonian lowland, Zagreb-Gric in the North-western continental Croatia, Gospic on the Lika plateau in the Dinaric mountains, and at two locations at the eastern Adriatic coast, Crikvenica located in the Kvarner Bay characterised by the maritime climate of the northern Adriatic under the strong influence of the mountainous, and Hvar at the middle Adriatic island of Hvar. Indices of precipitation extremes have been calculated according to the WMO report on the activities of the working group on climate change detection. This enables comparison of already obtained results for western and central Europe to the transitional area from the Pannonian lowland to the eastern Adriatic coast in more detail. During the 20th century there was a tendency for precipitation decrease all over Croatia. It is mostly pronounced and statistically significant at northern coast (Crikvenica: 18%/100yrs) as a result of decrease in all seasons. In other parts decreasing annual trends are resulting from precipitation decreases in all seasons especially in spring, except for summer. The annual anomalies show very large variability since 1901 and continue also at the beginning of the 21st century. Trends in precipitation indices point at the increase in annual number of dry days (Rd>1.0 mm), significant at 5% confidence level along the coast and the city of Zagreb. At the same time it is a very weak negative trend in moderate wet days (Rd>R75%) and no change in very wet days (Rd>95%). High precipitation amounts that fall on very wet days (R95%T) show practically no change. Highest 1-day and 5-day precipitation amounts have large interannual variability, without significant trend, but with negative sign in 5-day maxima all over Croatia and in 1-day maxima in mountainous and lowland areas. The results show that in drying area, such as Croatia, there is no signal of large changes in extremes that concerns high amounts and frequency of wet and very wet days. The decrease in annual precipitation is the consequence of changes in frequency of rainy days of lower intensity and increased frequency of dry days.