Estimativa de par?metros hidrodin?micos de aqu?feros em ?reas de embasamento atrav?s de m?todos indiretos.

A recess?o representa o per?odo em que a vaz?o de um rio ? mantida predominantemente pela restitui??o de ?guas subterr?neas, constituindo, ent?o, o fluxo de base. Em bacias hidrogr?ficas, o coeficiente de recess?o ? um par?metro hidrol?gico que informa a taxa de produ??o do fluxo de base. O coeficiente de recess?o (ou de esgotamento) pode ser determinado de forma indireta por diversos m?todos gr?ficos com uso de s?rie de dados hidrol?gicos. A partir deste coeficiente ? poss?vel calcular outros par?metros importantes, como a transmissividade de aqu?feros. O coeficiente de recess?o possibilita ainda obter informa??es sobre as vaz?es m?nimas em canais de drenagem, que, usualmente, s?o obtidas atrav?s de outros ?ndices hidrol?gicos, como o Q7,10, muito empregado na gest?o de recursos h?dricos superficiais. No presente trabalho foram determinados os coeficientes de recess?o, a transmissividade e o coeficiente de armazenamento para seis bacias, atrav?s de diversos m?todos indiretos. Foram calculados tamb?m alguns ?ndices morfom?tricos, como a amplitude, o slope index e o ?ndice de compacidade, permitindo assim a correla??o entre as caracter?sticas morfom?tricas das bacias e os par?metros hidrodin?micos das mesmas. Os m?todos utilizados para a determina??o do coeficiente de recess?o foram: Maillet, Boussinesq, Correla??o, Matching Strip e Drogue. Para a obten??o da transmissividade, al?m de utilizar os coeficientes de recess?o dos m?todos de Maillet e Boussinesq, utilizou-se tamb?m o m?todo de Brutsaert; entretanto, este ?ltimo apresentou resultados muito superiores aos tradicionalmente descritos na literatura. As bacias estudadas ocorrem em regi?es com predom?nio de rochas gn?issicas e gran?ticas, e sob vegeta??o, clima e uso e ocupa??o semelhantes, localizadas na por??o centro-sul de Minas Gerais. Uma delas ? a bacia do rio Maracuj?, inserida no Complexo Metam?rfico Ba??o, no Quadril?tero Ferr?fero (QF). As outras bacias est?o localizadas a oeste do QF, no Complexo Metam?rfico Campo Belo. Verificou-se que, dentre os m?todos utilizados, o de Boussinesq apresentou a melhor rela??o entre seus coeficientes de recess?o e transmissividades quando confrontados com outros ?ndices das bacias, tais como ?rea, Q7,10, ?ndice de compacidade e slope index. A partir da an?lise dos resultados e de dados pr?vios constatou-se ainda que as bacias maiores e com relevo mais aplainado t?m maior capacidade de armazenar ?gua, liberando-a mais lentamente, contribuindo assim para a manuten??o sustent?vel do fluxo de base. Nas bacias de cabeceira este comportamento ? inverso. A estimativa das reservas renov?veis a partir dos coeficientes de recess?o forneceu resultados que podem ser utilizados como ferramenta de determina??o da quantidade de ?gua subterr?nea a ser explotada nas bacias. Os resultados revelaram que o coeficiente de recess?o constitui um par?metro eficiente e pr?tico para se avaliar importantes par?metros de interesse para a explora??o de ?gua subterr?nea e para a gest?o de bacias hidrogr?ficas.The recession represents the period when the river?s flow is maintained predominately by subterranean water return, so establishing the base flux. In hydrographic basins, the recession coefficient (or of drain) can be determined in an indirect manner by several graph methods using series of hydrologic data. From this coefficient is possible to calculate other important parameters, like the aquifer transmissivity. The recession coefficient still turns possible to get information about the minimal flow in the drainage channels, that usually are obtained toward other hydrological indexes, as the Q7,10, frequently used in management of superficial hydrological resource. In this work were determined the recession coefficient, the transmissivity and the store coefficient for six basins, towards several indirect methods. There were also calculated some morfometrics indexes, how the amplitude, the slope index and the compactness index, allowing thus the correlation between the morfometrics characteristics of the basins and their hemodynamic parameters. The methods used to determine the recession coefficient were: Maillet, Boussinesq, Correlation, Matching Strip e Drogue. To obtain the transmissivity, beyond the use of recession coefficient of Maillet?s and Boussinesq?s methods, the Brutsaert method was used too; however, this last method presented results much higher than the traditionally described in the literature. The basins studied occur in regions where the predominance is of granite-gnaissic rocks, and under similar vegetation, climatic, use and occupancy, located in the Central-South region of Minas Gerais state. One of those is the Maracuj? river basin, inserted in the Metam?rfico Ba??o complex, on Quadril?tero Ferr?fero (QF). The other basins are located at west of QF, on the Metam?rfico Campo Belo complex. Regarding the used methods, was verified that, the Boussinesq method presented the best relation between their recession and transmissivity coefficients when confronted with others indexes of the basins, as area, Q7,10, compactness index and slope index. From the analysis of the results and the previous results were ascertained that the biggest basins with most plan relief have bigger capacity to store water, liberating it slowly, so contributing for the sustainable maintenance of the base flux. In head basins this behavior is reverse. The estimate of renewable reserves from the recession coefficient provides results that can be used how a tool of determination of subterranean water quantity to be explored on the basins. The results revealed that the recession coefficient constitute an efficient parameter of interest for the subterranean water explore and to manage the hydrographic basins

Aquifer parameter estimation through the recession coefficient in basement areas of Minas Gerais.

O coeficiente de recessão (α) indica a taxa de produção do fluxo de base, que representa a porção da vazão de um rio mantida pela restituição de águas subterrâneas. Ele pode ser obtido através da análise de hidrogramas. Esse coeficiente possibilita o cálculo de parâmetros importantes, como a transmissividade de aquíferos, as reservas renováveis de água subterrânea e as vazões mínimas em canais de drenagem, que, usualmente, são obtidas através de outros índices hidrológicos, como o Q7,10, muito empregado na gestão de recursos hídricos superficiais. As bacias estudadas estão localizadas na porção centro-sul de Minas Gerais, em regiões de rochas granito-gnássicas, sob vegetação, clima e uso e ocupação semelhantes. Os resultados obtidos, no estudo, foram satisfatórios, indicando os métodos de determinação de coeficiente de recessão como promissores para se caracterizar a produção de água subterrânea em bacias hidrográficas do embasamento cristalino. A restituição de águas subterrâneas para os sistemas de drenagem é maior nas áreas de relevo mais suave, indicando que estas constituem as melhores áreas de recarga.The recession coefficient (α) indicates the production rate of the base flow, that represents the part of the river flow which is predominately maintained by groundwater restitution. It can be obtained through hydrographic analysis. This coefficient allows the calculation of important parameters, such as aquifer transmissivity, renewable groundwater reserves, and low flow in drainage channels that usually are obtained through other hydrological indexes, such as the Q7,10, frequently used in the management of surficial hydrological resources. The studied basins are located in the Central-Southern region of the Minas Gerais State, in areas of granite-gneissic rocks, with similar vegetation, climate and landuse. The results were satisfactory, showing that the determination methods for the recession coefficients may be used to characterize groundwater production in the hydrographic basins of the crystalline basement. The groundwater discharged into the drainage systems is greater in areas with smoother relief, indicating that they constitute the best recharge areas

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