Métodos sísmicos ativos e passivos aplicados para caracterização da barragem do Paranoá em Brasília-DF

Dissertação (mestrado) — Universidade de Brasília, Instituto de Geociências, Programa de Pós-Graduação em Geociências Aplicadas, 2022.As falhas recentes e fatais em barragens de rejeitos no Brasil geraram grandes considerações sobre as políticas de segurança em torno das barragens de terra. A busca por metodologias voltadas à obtenção de informações sobre as características internas de uma barragem tem crescido bastante no país desde então. Os métodos geofísicos têm potencial aplicabilidade para investigações em barragens, e a contribuição dos métodos de sísmica de refração e de ondas de superfície é bem conhecida, uma vez que as velocidades das ondas P e S podem ser associadas a módulos elásticos de interesse geotécnico. Poucos estudos foram desenvolvidos cobrindo grandes porções de maciços de grandes barragens de reservatório de água. Apesar de serem estruturas com menor risco agregado quando comparadas às barragens de rejeitos, as barragens de reservatórios de água também estão sujeitas ao desenvolvimento de patologias internas. Considerando o contexto construído em torno dos métodos sísmicos para investigações geotécnicas, foram utilizados os métodos de tomografia de tempos de percurso, MASW e SPAC para obter os modelos Vp e Vs da barragem Paranoá, a maior barragem de Brasília, capital federal do Brasil. O objetivo deste estudo foi interpretar características internas da barragem a partir de modelos de velocidade, identificar anomalias que poderiam estar associadas à saturação de água a partir da distribuição da razão Vp/Vs e avaliar aspectos gerais das metodologias utilizadas para avaliação de barragens de terra. A utilização de métodos sísmicos foi uma forma prática e eficiente para cálculo de modelos de velocidade, permitindo a caracterização de várias feições de uma barragem de terra e enrocamento, como delineamento do solo de fundação, zonas de menor compactação, nível de água e possíveis anomalias de saturação no maciço. Uma análise das profundidades de investigação alcançadas sugere que essa variável é provavelmente específica do local, ao invés de uma questão exclusiva de instrumentação de fonte e receptor.Recent and deadly tailings dam failures in Brazil triggered massive considerations on the safety policies around earth dams. The search for methodologies aimed at obtaining information about internal features of a dam has grown considerable in the country ever since. Geophysical methods have potential applicability for investigations on dams, and the contribution of seismic refraction and surface wave methods is well known, since the P and Swaves velocities can be associated with elastic modules of geotechnical interest. Few studies have been developed covering great portions of the massif of large water reservoir earth dams. Despite being structures with a lower aggregate risk when compared to tailings dams, water reservoir dams are also subject to the development of internal pathologies. Considering the context built around seismic methods for geotechnical investigations, the traveltimes tomography, MASW and SPAC methods were used to obtain Vp and Vs models of the Paranoá dam, the largest dam of Brasília, the federal capital of Brazil. The goal of this study was to interpret internal features of the dam from velocity models, identify anomalies that could be associated with water saturation from Vp/Vs ratio distribution and evaluate general aspects of the used methodologies for general earth dam assessment. The use of seismic methods were practical and efficient ways to obtain velocity models, allowing the characterization of various features of an earth and rockfill dam, such as delineation of foundation ground, lower compaction zones, water level and possible saturation anomalies. An analysis of the depth range obtained within velocity models suggests that the depth of investigation is likely to be site specific, rather than exclusive matter of source and receiver instrumentation

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora