Risco climático, vulnerabilidade socioespacial e eventos climáticos extremos relacionados ao calor e ao frio no estado do Rio Grande do Sul- Brasil

Pós-graduação em Geografia - FCT

Influence of atypical pluviosity on phytoplankton assemblages in a stretch of a large sub-tropical river (Brazil)

This study aimed to evaluate the influence of alterations in pluviosity and ecological variables on microphytoplankton (> 20 mu m) structure (composition, richness, diversity, and abundance) and its biomass (chlorophyll-a), comparing different regions in a stretch of the low Igua double dagger u River and in some tributaries. Phytoplankton was sampled in 10 stations (5 in Igua double dagger u River and 5 in tributaries) during a dry period (April/2004) and an atypical rainy period (June/2004). The conductivity showed significant difference among the sampling points. Temperature, dissolved oxygen, pH, silicate, and nitrate showed significant differences between the dry and wet periods. Phytoplankton was composed of 149 taxa, and the most representative class was Chlorophyceae (71 taxa), followed by Bacillariophyceae (35 taxa), and Cyanophyceae (25 taxa). During the rainy period, stations of Igua double dagger u River showed higher taxa number and total density compared to the tributaries, but the values were similar in the dry period. Tributaries presented higher diversity and equitability in both periods. Except by two stations in Igua double dagger u River, the higher taxa number, densities and biomass occurred in the dry period, associated to low levels of suspended matter. The canonical correspondence analysis indicated the dominance of Bacillariophyceae and Chrysophyceae in the rainy period related to nitrate and suspended matter. Two other groups were observed in the dry period: one formed by Cyanophyceae, Dinophyceae, and Rhodophyceae, related to temperature and nitrite and other by Euglenophyceae and Chlorophyceae related to total phosphorus and silicate. The groups suggest adequate conditions of the physical, chemical and climatic factors to the establishment of the algae classes. Phytoplanktonic assemblages responded quickly to the environmental regional variations under strong influence of pluviosity, while in the dry period, homogeneity among stations and environmental variables was observed. The importance of climatic events is relevant in ecological studies in a temporal scale.

Contribution to the discussions on the origin of the cerrado biome: Brazilian savanna

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Widespread Amazon forest tree mortality from a single cross-basin squall line event

Climate change is expected to increase the intensity of extreme precipitation events in Amazonia that in turn might produce more forest blowdowns associated with convective storms. Yet quantitative tree mortality associated with convective storms has never been reported across Amazonia, representing an important additional source of carbon to the atmosphere. Here we demonstrate that a single squall line (aligned cluster of convective storm cells) propagating across Amazonia in January, 2005, caused widespread forest tree mortality and may have contributed to the elevated mortality observed that year. Forest plot data demonstrated that the same year represented the second highest mortality rate over a 15-year annual monitoring interval. Over the Manaus region, disturbed forest patches generated by the squall followed a power-law distribution (scaling exponent alpha = 1.48) and produced a mortality of 0.3-0.5 million trees, equivalent to 30% of the observed annual deforestation reported in 2005 over the same area. Basin-wide, potential tree mortality from this one event was estimated at 542 +/- 121 million trees, equivalent to 23% of the mean annual biomass accumulation estimated for these forests. Our results highlight the vulnerability of Amazon trees to wind-driven mortality associated with convective storms. Storm intensity is expected to increase with a warming climate, which would result in additional tree mortality and carbon release to the atmosphere, with the potential to further warm the climate system. Citation: Negron-Juarez, R. I., J. Q. Chambers, G. Guimaraes, H. Zeng, C. F. M. Raupp, D. M. Marra, G. H. P. M. Ribeiro, S. S. Saatchi, B. W. Nelson, and N. Higuchi (2010), Widespread Amazon forest tree mortality from a single cross-basin squall line event, Geophys. Res. Lett., 37, L16701, doi:10.1029/2010GL043733.

Regional hydroclimatic variability and Brazil's 2001 energy crisis

Purpose - This paper seeks to address the issue of persistent and widespread drought conditions during 2000 and 2001, which were the apparent cause of the decline of water levels in the reservoirs of Brazilian hydroelectric power plants. Design/methodology/approach - This issue is addressed here through a case study of the hydroclimatology of the Paraíba river basin, in Southeast Brazil, home to four large multi-purpose operational reservoirs. Findings - The data analysis shows that neither changes in the frequency nor magnitude of extreme hydrological events (droughts and floods) nor in annual rainfall amounts can be detected from the existing climate record. The explanation is consistent with the fact that the terrestrial water and energy cycles are tightly, and non-linearly, coupled through evapotranspiration. Research limitations/implications - Therefore small change in the seasonality of rainfall can have a significant impact on the basin's overall hydrologic regime, and thus on the availability of water resources. Originality/value - Often, adaptation and resilience to climate variability are discussed in the context of catastrophic events such as floods and droughts. This study suggests that a different type of impacts, those associated with subtle, yet persistent changes of seasonality in the terrestrial water cycle, cannot be ignored in studies of long-term sustainability of water resources. © Emerald Group Publishing Limited.

Análise das tragédias de Janeiro de 2011, no bairro jardim Zaíra, município de Mauá/SP: uma análise episódica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A importância da adoção de planos preventivos de defesa civil nos municípios: o caso de Ribeirão Preto (SP)

Pós-graduação em Geografia - IGCE

As chuvas no Paraná: Variabilidade, teleconexões, e impactos de eventos extremos

Pós-graduação em Geografia - FCT

Tipologia climática: subsídios para uma análise teórico-metodológica do clima na região metropolitana de São Paulo

The present study aims to establish the mapping units climate Metropolitan Region of São Paulo, with a more refined analysis in the study of extreme weather events to contribute to the adaptation of populations made vulnerable in the face of extreme weather events, and also as an aid local public policies, from a new perspective climate. As criteria of analysis, temperature, precipitation, altitude and use and occupation of land. For this we use as a work methodology broad literature review, fieldwork and use of geotechnology in the proposed mapping generation

Uso e ocupação da terra e vulnerabilidade a alagamento na área central da cidade de São Paulo: o caso da subprefeitura Sé

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A gênese e a distribuição socioespacial das chuvas no município de Ubatuba-SP

This monograph aims to contribute to the understanding and analysis of extreme events and its correlation with anthropogenic actions, in order to understand the levels of human interference in the environment and to identify potential social and environmental damage that such events may result in Ubatuba, located on the northern coast of São Paulo state. Therefore, two strategies were established, on one hand, episodic analysis of extreme weather events, and on the other, the analysis of the impact of atmospheric phenomena in everyday society. In this case we gave greater emphasis to analysis years that had higher total rainfall. In this sense, the research was based on the standard deviation technique and percentages, which supported to characterize the exceptional rainy years, in addition, use of rhythm analysis technique that has helped to identify the active atmospheric systems. From a qualitative point of view, field works were carried out in order to make use of news by the local press and civil defense for years considered extreme (positive standard deviation). From this, it was analyzed how the extreme episodes of rainfall trigger repercussions in geographic space. Also the spatial distribution of rainfall were carried out by means of quantitative analysis of six rain gauges. It was found that the highest occurrences of impacts, are located in the central areas of the city, as well as the highest rainfall totals. In fact, Ubatuba/SP suffers from very high rainfall totals and has a singularity on the climate...

Combining ALOS/PALSAR derived vegetation structure and inundation patterns to characterize major vegetation types in the Mamiraua Sustainable Development Reserve, Central Amazon floodplain, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Processos geodinâmicos associados a mudanças de uso da terra: o caso da microbacia hidrográfica do Córrego Caçula (Ilha Solteira - SP)

Pós-graduação em Engenharia Civil - FEIS

Socio-climatic hotspots in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Geographical variation in genetic structure of an Atlantic Coastal Forest frog reveals regional differences in habitat stability

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)