Proceedings of X Iberian Symposium on the Minho River Hydrographic Basin

Author(s):  
Carlos Antunes

No X Simpósio Ibérico Sobre a Bacia Hidrográfica do Rio Minho, organizado pelo Aquamuseu do Rio Minho/Câmara Municipal de Vila Nova de Cerveira (Portugal) e co-organizado pelo Centro Interdisciplinar de Investigação Marinha e Ambiental – Universidade do Porto, foram abordados os temas que abrangeram áreas desde a geoquímica de sedimentos e formas erosivas do leito rochoso do rio Minho; as mudanças climáticas numa perspetiva da futura gestão da água e nos efeitos já evidentes ao nível das comunidades biológicas; importância da gestão dos recursos da pesca no rio Mouro pela monitorização e aplicação de regras específicas de exploração; diagnóstico e medidas em curso para a conservação das populações de peixes migradores; a ameaça dos poluentes emergentes; a divulgação de novos registos de invertebrados encontrados no rio Minho (abordagem taxonómica); evidências da colaboração entre pescadores e investigadores para um melhor conhecimento social da comunidade piscatória, da sua atividade e da sua contribuição para o processo de gestão; comunicação de ciência e educação ambiental. No âmbito da mesa-redonda (workshop), em modelo aberto à comunidade, onde participaram pescadores, foram apresentados resultados de trabalhos no âmbito do Conhecimento Ecológico Local (Etnobiologia), em que os próprios tiveram a oportunidade de manifestar as suas opiniões relacionadas com a atividade da pesca. Houve ainda oportunidade de entregar os prémios referentes ao concurso de ilustração científica “Rio Minho, Biodiversidade e Artes de Pesca”, cuja exposição completa esteve patente na Bienal de Cerveira.

2019 ◽  
Vol 2 ◽  
pp. 28
Author(s):  
Marcelo Pereira de Barros ◽  
Ana Paula Lima da Silveira ◽  
Bruna Reis Ferreira

As aves destacam-se dentro dos vertebrados por serem um grupo diverso e adaptado a diferentes ambientes, a composição da comunidade de aves de um determinado local é um importante bioindicador ambiental, pois ela reflete alterações recentes ou pretéritas de determinada área. Na Bacia Hidrográfica do Rio dos Sinos, as pressões sobre os remanescentes de ecossistemas naturais são intensas em decorrência da urbanização crescente, do estabelecimento de indústrias e da ampliação das fronteiras agrícolas, esses fatores associados geram a redução e fragmentação de habitats, com impactos irrecuperáveis para a flora e a fauna. Devido à escassez de dados sobre a avifauna do município de Taquara, o presente estudo teve como objetivo levantar informações sobre o grupo, listando as espécies de aves locais. Entre agosto de 2016 e junho de 2017 foram realizadas quatro amostragens mensais em duas áreas rurais do município, totalizando 44 campanhas de observação e 132 horas de esforço amostral. As espécies foram identificadas e classificadas conforme sua frequência de ocorrência mensal, em espécies comuns e raras. Foram registradas 133 espécies distribuídas em 47 famílias, o que representa mais de 20% das espécies ocorrentes para o estado. Ao longo do período amostrado, 90 espécies foram classificadas como comuns e 47 consideradas raras para as áreas pesquisadas.Palavras-chave: Aves. Bacia hidrográfica do Rio dos Sinos. Preservação.ABSTRACTBirds stand out within vertebrates because they are a diverse group adapted to different environments. The composition of the bird community of a certain place is an important environmental bioindicator since it reflects recent or previous environmental disturbances of a certain area. In the Sinos River Basin, environmental pressures on the remnants of natural ecosystems are intense as a result of increasing urbanization, the establishment of industries and expansion of agricultural frontiers which generate habitat reduction and fragmentation with irrecoverable damages on flora and fauna. Due to the scarcity of data on the avifauna of the municipality of Taquara, the present study aimed to gather information and list the species of local birds. Between August 2016 and June 2017, four monthly samplings were carried out in two rural areas of the municipality, totaling 44 observation campaigns and 132 hours of sample effort. The species were identified and classified as common and rare according to their frequency of occurrence. There were 133 species distributed in 47 families, representing more than 20% of the species that occurred in the state. During the sampled period, 90 species were classified as common and 47 were considered rare for the areas surveyed.Keywords: Birds. Hydrographic basin of Sinos River. Preservation.


Limnology ◽  
2021 ◽  
Author(s):  
Renata Manconi ◽  
Dirk Erpenbeck ◽  
Jane Fromont ◽  
Gert Wörheide ◽  
Roberto Pronzato

AbstractA recent discovery of freshwater sponges in an unexplored hydrographic basin in north-western Australia provided the opportunity to investigate the genus Corvospongilla Annandale (Spongillida: Spongillidae) using integrative systematics. Emendation of the genus diagnosis is provided. A comparative analysis of a Corvospongilla global dataset of morphological traits together with biogeographic patterns disclosed a new Australasian Corvospongilla species and along with molecular analyses provided the basis for a phylogenetic and phylogeographic tree for some Asian, Afrotropical and Australasian lineages.


Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 111
Author(s):  
Ana Gonzalez-Martinez ◽  
Carmen De-Pablos-Heredero ◽  
Martin González ◽  
Jorge Rodriguez ◽  
Cecilio Barba ◽  
...  

The aim of this research was to find out the morphometric differentiation of six native freshwater species in the Guayas Hydrographic Basin (Ecuador) by means of discriminant analysis. A total of 1355 mature fishes (Cichlasoma festae, Andinoacara rivulatus, Dormitator latifrons, Bryncon dentex, Hoplias microlepis and Leporinus ecuadorensis) were captured and 27 morphometric measurements and 20 landmarks were used. Two-way analysis of variance with species and sex as fixed factors and discriminant analysis were applied. The selection of the most discriminant variables was made applying the F of Snedecor, Wilks’-Lambda and the 1-Tolerance. While sex within species had no significant effect on the morphology, differences among species were significant. Twenty-seven morphological variables showed highly significant differences among six native freshwater species. Nine biometric variables with high discriminant power were selected. The six species analyzed were discriminated by the morphometric models generated, thus showing that discriminant analysis was useful for differentiating species. The morphometric differentiation by discriminant analysis is a direct, simple and economic methodology to be applied in situ in rural communities. It favors the implementation of a livestock development program and it could be used with other native freshwater species in the Guayas Hydrographic Basin.


1999 ◽  
Vol 22 ◽  
pp. 8-22 ◽  
Author(s):  
Claudio Valdetaro Madeira ◽  
Leonardo Borghi

The present work deals with stratigraphy, sedimentology and geomorphology of Quaternary sedimentary deposits of Santana river hydrographic basin. through facies and arquitectural elements descriptions. Based on five arquitectural elements characterized by ten lithofacies the following structural and depositional evolutions were scheduled: 1) formation of thick soil horizons over the basement; 2) deposition of several alluvial fans on the soils (lithofacies Gm and Fm, element E); 3) above an unconformity we can recognize a fluvial system, characterized by a non well drainage floodplain. This floodplain is overlaid by high-sinuosity channels (lithofacies Sp and St, element C) genetically related to other floodplain (lithofacies Fl and Fsc, element A) where the interfigering with crevasse splay deposits (lithofacies Sh, Sl, and Sp, element B) is ususal; 4) an erosional phase suceed by a new depositional phase characterized by low-sinuosity channels (lithofacies Gp, Gt, Sp, St, and Sh, element D). Nowadays anthropogenic action produces a new erosional phase. The geomorphological features recognized were scheduled: 1) the present floodplain 1.5m above the river bed; 2) the low terrace ( named T2) 5m above the river bed and its deposits is related to element D; 3) the high terrace ( named T1) 11m above the river bed and its deposits is related to elements A, B, C and E.


2021 ◽  
Vol 5 (3) ◽  
pp. 1475-1491
Author(s):  
Gisele Marilha Pereira Reginatto ◽  
Regiane Mara Sbroglia ◽  
Camilo Andrade Carreño ◽  
Bianca Rodrigues Schvartz ◽  
Pâmela Betiatto ◽  
...  

In translational landslide susceptibility analysis with SHALSTAB (Shallow Landsliding Stability Model), the resolution of the digital elevation model (DSM) is determinant for defining the type of mapping generated (preliminary or not). In this study, in order to verify the influence of the SDM scale on the SHALSTAB stability classes, susceptibility maps were prepared at two scales: 1:50,000 and 1:10,000. The study area was the Garcia River watershed, belonging to the municipality of Blumenau, Santa Catarina, affected by landslides in the 2008 catastrophe, which enabled the validation of the simulations with the scars mapped in the field. Thus, the influence of scale on the distribution of the model's stability classes and on its performance was verified. SHALSTAB performed better at the 1:10,000 scale, predicting 70% of the instabilities in a percentage of unstable area approximately three times smaller than at the 1,50,000 scale.


2019 ◽  
Author(s):  
Hellen Braboza ◽  
Suze Guimarães ◽  
Fabio Vieira
Keyword(s):  

2015 ◽  
Vol 2 ◽  
Author(s):  
Candeias Marta ◽  
Alves-Pereira Isabel ◽  
Lança Maria ◽  
Ferreira Ana ◽  
Quintella Bernardo ◽  
...  

2019 ◽  
Vol 1 ◽  
pp. 1-2
Author(s):  
Andrea Lopes Iescheck ◽  
Patricia Andréia Paiola Scalco

<p><strong>Abstract.</strong> This work is part of a research project that aims at the automatic determination of knickpoints and the assessment of morphometric and hypsometric parameters of Mirim Lagoon Hydrographic Basin, using Shuttle Radar Topography Mission digital elevation model (SRTM-DEM) and spatial analyses.</p><p>The analysis of geomorphologic systems is done using computational treatment of data obtained by remote sensing, especially those obtained by SRTM. These data permit the elaboration of a topographic model for the Earth surface and provide a base for studies in several units of geomorphologic analyses (geomorphologic systems), such as hydrographic basins.</p><p>The most usual technique for derivation of relief morphologic attributes is based on digital elevation models (DEMs) and digital hydrographic nets. Computational routines are applied on those data for acquisition of the hydrography and drainage anomalies. The DEMs and the hydrographic nets must have either morphologic or hydrologic consistency to validate the results obtained in the morphometric analyses.</p><p>More specifically, this study aims at describing the method and related results regarding the validation of the vertical accuracy of SRTM-DEM through a kinematic positioning based on the Global Navigation Satellite System (GNSS), in the Mirim Lagoon Hydrographic Basin region. Mirim Lagoon Hydrographic Basin is as cross-border basin located on the Atlantic coast of South America, and covers an area of 58,407.78&amp;thinsp;km<sup>2</sup>, where 47% of this area is in Brazil and 53% in Uruguay.</p><p>Several studies deal with the validation of Digital Elevation Models (DEMs) and SRTM data using different GNSS surveying methods and receivers. The innovation of this work is the methodology developed to achieve the suitable accuracy for the control points coordinates to validate the SRTM-DEM of Mirim Lagoon Hydrographic Basin. The study used the kinematic relative positioning method with a recording rate of 1 second and without reference stations for post-processing with the precise point positioning (PPP) method. This methodology allowed covering a large area with reference stations being very far from the surveyed region and with different geodetic reference systems (two countries).</p><p>The methodology entails the GNSS data acquisition and post-processing, the transformation from geometric heights into orthometric heights, the SRTM-DEM mosaic, the extraction of homologous points in the SRTM-DEM and the statistical analyses for validating the model.</p><p>The study used a GNSS receiver of dual-frequency with recording rate of 1 second to collect a total of 275,916 points with 3D coordinates. Those points were post-processed using the PPP method with the Canadian Spatial Reference System &amp;ndash; Precise Point Positioning (CSRS-PPP), and the ellipsoidal height was converted into orthometric height through the software INTPT geoid. During this work, we used the geopotential model (EGM96) to transform height differences between two countries, Brazil and Uruguay.</p><p>In order to obtain the SRTM-DEM we used 15 SRTM images, version 3, band C, with a spatial resolution of 1 arcsecond (approximately 30&amp;thinsp;m). These images were individually processed to obtain the Digital Elevation Model Hydrologically Consistent (DEMHC) and to treat the inconsistencies. Afterwards, we created a mosaic with the 15 images.</p><p>In the statistical analysis we examined the magnitude of absolute errors in the SRTM data. These errors were named discrepancies between the SRTM heights and the heights of GNSS survey points. After the post-processing and the heights conversion, the GNSS survey points were considered accurate and used as a reference for SRTM-DEM validation. The goal of the statistical analysis was to verify if the absolute vertical precision of the DEM data exceeds 16&amp;thinsp;m, according to the precision specifications of the DEM SRTM.</p><p>Results showed that the vertical mean absolute error of the SRTM-DEM vary from 0.07&amp;thinsp;m to &amp;plusmn;&amp;thinsp;9.9&amp;thinsp;m with average of &amp;minus;0.28&amp;thinsp;m. This vertical accuracy is better than the absolute vertical accuracy value of &amp;plusmn;&amp;thinsp;16&amp;thinsp;m published in the SRTM data specification and validates the SRTM-DEM. Besides that, even considering different slopes and different heights the statistics showed that SRTM-DEM could be validated, in spite of the results for lower and flat area were more accurate than the ones for a higher area with high slope.</p>


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