Estado del arte de las metodologías para delimitación de rondas hídricas en el contexto internacional y local

Trabajo de investigaciónLas rondas hídricas o zonas ribereñas ripariana son una estrecha franja que se ubica adyacente bordeando los ríos, lagos, embalses, humedales y planicies de inundación (lovett, 2002), desempeñando importantes funciones ecológicas, entre ellas está la función de filtro para ingresos de contaminantes derivados de las actividades productivas que generan contaminación difusa y que son las más difíciles de controlar. Esta capacidad amortiguadora de los ingresos radica en el retardo del tiempo de residencia hidráulica que realiza la vegetación litoral (möller, 2011). La composición de la vegetación las zonas amortiguadoras pueden ser arbóreas, gramíneas o una combinación de las dos, tolerantes a las inundaciones y a la depositación de sedimentos, la amplitud de las franjas es variable y su eficiencia depende de diversos factores, existen dos enfoques para diseñarlas, el de anchos fijos, y el de franjas de amortiguamiento variable o de precisión. En Colombia se han establecido anchos fijos en la normativa ambiental, sin embargo, a partir de la promulgación del plan de desarrollo 2010 - 2014, las rondas hídricas fueron definidas y presentan un enfoque de ancho variable gracias al área aferente, que permite proveer hábitat de dispersión a los organismos acuáticos, aéreos y terrestres, no obstante el ancho de ésta, no tiene el mismo valor para todos y su óptimo funcionamiento dependerá de la función cuya conservación se desee priorizar.EspecializaciónEspecialista en Recursos Hídrico

Relationship between hydrology and aquatic ecosystems in the Araguaia river floodplain

O rio Araguaia se constitui no principal sistema fluvial que percorre o Brasil central. Neste artigo, são apresentadas algumas observações sobre o seu comportamento hidrogeomorfológico e suas aplicações no estudo de ecossistemas aquáticos. Os resultados foram gerados pelo processamento de dados de vazão de uma série histórica de 35 anos de registro (1970 a 2004), em nove estações hidrológicas, envolvendo o alto, médio e baixo curso. A distribuição de vazões no curso médio resulta atípica nas cheias extremas, pois o rio perde até 30% de sua vazão. No total, foram definidos três tipos de enchentes e dois mecanismos particulares de armazenamento e transferência de fluxos, que explicam as perdas de fluxos no médio curso. Três são os principais fatores condicionantes da perda de vazão: a) a existência de uma planície aluvial bem desenvolvida, b) a existência de um complexo de sistema de lagos na planície aluvial, c) a vegetação dominantemente arbórea, que freia a onda de cheia e contribui para o armazenamento de água na planície aluvial.The Araguaia river is the most important fluvial system draining the Cerrado biome of Brazil. Results are presented here on the hydrogeomorphologic behavior of this fluvial system and its effect on the floodplain ecosystems. Discharge from nine gauge stations in the upper, middle and lower course of the Araguaia River, from 1970 to 2004, were analyzed. The hydrological regime depends strongly on the tropical wet-dry climate, with floods from January to May and low water between June and September. In the upper and lower courses, there is a high variation between maximum and minimum peaks because the underdevelopment of the floodplain, while in the medium course the flow peaks are smoothed by the presence of a well-developed river floodplain. In this area, the river can lose up to 30% in water discharge, which is stored in the floodplain. Three types of flood categories were defined, and two mechanisms of flow storage and transfer were identified, explaining the discharge loss in the middle course. Three main mechanisms produce the water loss mid-course: the sponge effect of the alluvial plain, the existence of a well-developed mosaic of lakes, and an arboreal-dominated vegetation stratum of alluvial forest.Facultad de Ciencias Naturales y Muse

Semblanzas ictiológicas iberoamericanas : Francisco Javier Lobón Cerviá

Fil: López, Hugo Luis. División Zoología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Ponte Gómez, Justina. División Zoología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

A influência das atividades mineradoras na alteração do pH e da alcalinidade em águas fluviais: o exemplo do rio Capivari, região do carste paranaense.

As atividades de mineração causam vários tipos de impactos ao meio ambiente. Este trabalho apresenta um estudo de impacto sobre recursos hídricos superficiais desenvolvidos numa bacia hidrográfica na região metropolitana de Curitiba (PR), onde se observaram modificações no pH e na alcalinidade nas águas do rio Capivari ocorridas num intervalo médio de doze anos. Foram avaliados 387 dias de amostragem da série 1986/1987 e 1.095 dias da série 1998/2000. Comparando-se as duas séries, observou-se que, ao longo deste período (1986-2000), a média do pH elevou-se, em média, 0,5 unidade, enquanto a alcalinidade aumentou em 15%. De 1980 a 2001, as áreas de mineração desta mesma bacia tiveram uma expansão de aproximadamente 47.000 m2/ano. Avaliações ao longo do rio revelaram, nos locais à jusante e mais próximos das pedreiras, que o pH apresenta valores mais altos, tornando-se alcalino, e a condutividade elétrica aumenta. Esses dados confirmam a hipótese de que a expansão das áreas de mineração provocaria alterações nos valores de pH e de alcalinidade das águas do rio Capivari

Recull de publicacions del Dr. Ramon Margalef López: Ajuda de cerca

Darrera actualització: 13 de gener de 2017Recull d’articles de revista, capítols de llibres, comunicacions i ponències a congressos publicats en monografies i revistes diverses per l'ecòleg Ramon Margalef López, i articles sobre el Dr. Margalef, publicats entre 1943 i 2015. Formen part del Fons Ramon Margalef López

Industrialscapes 2.0.: transformació del marge esquerre del riu Tordera al seu pas pel polígon industrial de Massanes

El següent projecte final de màster es basa la transformació del marge esquerre del riu Tordera al seu pas pel polígon industrial de Massanes, a la comarca de La Selva. Es tracta d’una zona industrial al costat del municipi d’Hostalric amb una alta recurrència a la inundació en períodes de 10 anys. En base a un anàlisi intencionat sobre la inundabilitat del territori, l’àmbit escollit per desenvolupar el projecte serveix com a exemple de transformació de tots aquells espais inundables on s’ha situat la indústria al llarg de les dècades, el qual s’està convertint en un problema recurrent a cada episodi intens de precipitacions. L’estratègia principall passa per intercambiar l’ús del sòl d’algunes parcel·les concretes a través del planejament urbanístic. D’aquesta manera aconseguim ordenar i connectar el sistema d’espais verds que permeten actuar en xarxa com a grans embornals en cas d’avingudes. La intervenció es centra la transformació de l’espai públic com a espai drenant i conductor d’escorrenties cap al curs principal del riu. Mitjançant un moviment de terres compensat i estratègic, es transforma l’espai verd en un parc linial que intercepta les principals escorrenties en cas d’inundació i les retorna a la Tordera. La vegetació proposada replica la disposició en quadrícula de les típiques plantacions de pollancres de la zona, intentant crear una gran pollancreda al llarg de tot el parc que combina els arbres de l’espècie Populus amb altres espécies de ribera. D’altra banda, en l’ambit privat inundable, es proposa una divisió de l’actual parcel·lació industrial amb la intenció de transformar el polígon en una nova indústria 5.0, molt més lligada al territori on s’ubica i aplicant les lògiques naturals necessàries per afrontar els efectes del canvi climàtic

Detection and Molecular Characterization of Giardia and Cryptosporidium spp. Circulating in Wild Small Mammals from Portugal

Simple Summary Wild small mammals can be a veterinary and public health concern, because they can act as reservoir hosts for numerous pathogens and potentially transmit them to humans, domestic animals and other wildlife species. This study represents the first investigation of the diarrhea-causing parasites Cryptosporidium spp. and Giardia spp. in wild rodents and shrews from Portugal. Cryptosporidium spp. was rarely and Giardia was frequently detected in the feces of the analyzed species, with the southwestern water voles (Arvicola sapidus) and Lusitanian pine voles (Microtus lusitanicus) showing the highest infection rates of Giardia spp. Genetic characterization based on common genomic marker sequences revealed the rodent-adapted Giardia microti and potentially zoonotic Cryptosporidium muris as the only circulating species. These findings suggest the limited role of wild rodents and shrews as natural sources of human infections in Portugal regarding the investigated parasites. Moreover, the host ranges of Giardia and Cryptosporidium spp. were extended and the obtained genetic sequences of Giardia microti are useful for future comparative studies. From the One-Heath perspective, this study helps to understand the epidemiology of Giardia spp. and Cryptosporidium spp. in wildlife. Cryptosporidium spp. and Giardia spp. are important diarrhea-causing protozoan parasites worldwide that exhibit broad host ranges. Wild small mammals can harbor host-adapted and potentially zoonotic species of both parasites. The aim of this study was to investigate Cryptosporidium spp. and Giardia spp. in wild rodents and shrews in Portugal, focusing on the protist's occurrence and genetic diversity. Molecular screening by PCR at the small subunit (SSU) rRNA gene locus of 290 fecal samples from wood mice (Apodemus sylvaticus), southwestern water voles (Arvicola sapidus), Cabrera's voles (Microtus cabrerae), Lusitanian pine voles (Microtus lusitanicus), Algerian mice (Mus spretus) and greater white-toothed shrews (Crocidura russula) in Northeast Portugal revealed the low occurrence of Cryptosporidium spp. (1%) and high occurrence of Giardia spp. (32.8%). The analysis revealed that species was the only significant factor associated with the increasing probability of Giardia spp. infection, with the highest prevalence reported in southwestern water voles and Lusitanian pine voles. Cryptosporidium and Giardia species determination at the SSU rRNA gene locus revealed C. muris and G. microti as the only circulating species, respectively. Subtyping of the glutamate dehydrogenase (gdh) and beta-giardin (bg) genes provided evidence of the high genetic diversity within the G. microti clade. This study suggests that rodent-adapted G. microti occurs to a large extent in cricetid hosts and supports the limited role of wild rodents and shrews as natural sources of human infections in Northeast Portugal regarding the investigated parasites. Moreover, this is the first record of G. microti in southwestern water voles, Lusitanian pine voles, Algerian mice, wood mice and Cabrera's voles and C. muris in Cabrera's voles. Finally, this study improves the database of sequences relevant for the sequence typing of G. microti strains and provides new insights about the epidemiology of Giardia spp. and Cryptosporidium spp. in wild rodents and shrews, two parasite genera of high importance for public and animal health

Morphodynamics in the confluence of large regulated rivers: the case of Paraná and Paranapanema Rivers

The confluence of the Paraná and Paranapanema Rivers is studied according to morphology and dynamics. It is probably the only example of this type of fluvial environment involving a large, tropical and intensive regulated river. Confluence channels were monitored along a hydrological cycle (high-low water level) in terms of morphology, flow velocity, magnitude, structure, and bedload dynamics. In this case, hydrology is controlled by the flow of the tributary, which develops a continuous and well-defined thalweg since the collector channel (a secondary channel of the Paraná River) that presents relatively large bedforms that reduce stream power by increasing roughness. Although significant differences in channel morphology were not observed along the hydrological year, bed material texture indicates that the channel bottom is suffering a slight armoring process. This is probably the reason for the large asymmetry of channel confluence where the depth of the tributary channel is larger than that of the main collector channel (the Paraná left branch). The Rosana Dam, closed in 1987 and located 26 km upstream from the confluence, is the cause of the changes in sediment transport and the generation of the channel pavement. With the closing of the Porto Primavera Dam (2000) in the Paraná River (27 km upstream from the confluence) a new morphodynamics is foreseen for this environment, and this paper can be seen a relevant pioneer reference for environmental monitoring and management