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Bioecologia e conservação das populações de Salmo trutta (L.) na bacia hidrográfica do rio Tua (NE Portugal)

Santos, Miguel Horta
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Dissertação de Mestrado
POR
Relevância na Pesquisa
26.4%
A truta-de-rio, Salmo trutta (L.), é uma espécie que habita os rios de montanha do Norte e Centro de Portugal. É frequentemente usada como atração turística e alvo importante e popular da pesca desportiva em Portugal e na Europa. Neste âmbito, o objetivo do presente trabalho consistiu no estudo da bioecologia e conservação da truta-de-rio no Nordeste Transmontano e em particular no Alto Tua, inserido na área protegida do Parque Natural de Montesinho. Durante a primavera de 2014 foi avaliada a integridade ecológica dos rios que constituem a bacia hidrográfica do Alto Tua. Foram avaliados parâmetros abióticos (qualidade da água e dos habitats aquáticos e ribeirinhos) e bióticos (comunidade de macroinvertebrados), em 15 pontos de amostragem selecionados ao longo dos cursos de água. Nos anos de 2013 e 2014 foram ainda amostradas as comunidades piscícolas. Selecionaram-se 15 locais de amostragem distribuídos pelos rios Mente, Rabaçal, Baceiro, Tuela e Tua. A amostragem das comunidades de peixes e invertebrados foi feita de acordo com o protocolo definido pela Diretiva Quadro da Água. Relativamente à espécie-alvo, a Salmo trutta, foram também determinados parâmetros populacionais e avaliado o uso dos recursos disponíveis (i.e. alimentação e habitat) nos diferentes rios truteiros. Na generalidade verificou-se que os sistemas aquáticos beneficiam de boa integridade ecológica...

Biological elements relatioships (macrophytes, macroinvertebrates and ichthyofauna) for different core river types across Europe for two different spatial scales

Pinto, Paulo; Morais, Manuela; Ilhéu, Maria; Sandin, Leonard
Fonte: Hydrobiologia Publicador: Hydrobiologia
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
26.65%
The objective of this study was to evaluate differences in correlations among Biological Elements and environmental parameters for different river types, analysed at two different spatial scales. A total of 82 sites, with at least good ecological status, were sampled across Europe, representing three core river types: Mountain rivers (26 sites); Lowland rivers (29 sites) and Mediterranean rivers (17 sites). At each site samples of macrophytes, macroinvertebrates and fishes were taken during spring, following the methodological procedures established by the European STAR project. Environmental parameters were also recorded, based on a site protocol developed by the European projects AQEM and STAR. Environmental parameters were divided into three categories: aquatic habitats (mesohabitat scale), global features (reach scale) and obligatory typology parameters of Water Framework Directive (WFD) (geographical scale).Data were analysed to evaluate at the two scales, first, relationships among biological elements, and second,relationships between biological elements and environmental parameters. Within each river type, correlation matrices (Bray–Curtis distance) were calculated separately for each biological element and for each category of environmental parameters. All biological elements were correlated (p<0.01) to the larger spatial scale: macrophytes and macroinvertebrates are more correlated in lowland and mountain rivers...

Integrity of fluvial fish communities is subject to environmental gradients in mountain streams, Sierra de Aroa, north Caribbean coast, Venezuela

Rodríguez-Olarte,Douglas; Amaro,Ahyran; Coronel,Jorge; Taphorn B.,Donald C.
Fonte: Sociedade Brasileira de Ictiologia Publicador: Sociedade Brasileira de Ictiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2006 EN
Relevância na Pesquisa
26.45%
We examined physical habitat and fish assemblages in rivers of the Aroa Mountains (Venezuela) with different levels of environmental protection due to the creation of Yurubí National Park within the drainage. We developed an Index of Biotic Integrity (IBI) and evaluated it using principal components analysis (PCA) and canonical correspondence analysis (CCA). Tributary rivers were divided into classes according to their origin (protected by the park) and physical characteristics of each, including substrate. Fishes were captured using standardized electrofishing. Fish communities showed greater species richness in heterogeneous habitat and protected rivers but overall abundance was higher in unprotected and impacted rivers. The IBI was sensitive to these differences and the scores were higher in protected rivers. The IBI detected degree of disturbance of fish communities without direct consideration of habitat parameters measured. The PCA revealed a gradient in substrate heterogeneity. Similarly, CCA revealed differences in fish assemblage composition along the environmental gradient and that varied with protection status of the river. The relationship between PCA and IBI scores was highly significant (r² = 0.61, P < 0.0001). The PCA and CCA analysis moderately validated the structure and predictability of IBI; but it is still necessary to refine the model and to extend its application for more time and over a wider area.

Landscape Genetic Structure of a Streamside Tree Species Euptelea pleiospermum (Eupteleaceae): Contrasting Roles of River Valley and Mountain Ridge

Wei, Xinzeng; Meng, Hongjie; Jiang, Mingxi
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 25/06/2013 EN
Relevância na Pesquisa
26.71%
We used landscape genetics and statistical models to test how landscape features influence connectivity or create barriers to dispersal for a mountain riparian tree species, Euptelea pleiospermum. Young leaves from 1078 individuals belonging to 36 populations at elevations of 900–2000 m along upper reaches of four rivers were genotyped using eight nuclear microsatellite markers. We found no evidence for the unidirectional dispersal hypothesis in E. pleiospermum within each river. The linear dispersal pattern along each river valley is mostly consistent with the “classical metapopulaton” model. Mountain ridges separating rivers were genetic barriers for this wind-pollinated tree species with anemochorous seeds, whereas river valleys provided important corridors for dispersal. Gene flow among populations along elevational gradients within each river prevails over gene flow among populations at similar elevations but from different rivers. This pattern of gene flow is likely to promote elevational range shifts of plant populations and to hinder local adaptation along elevational gradients. This study provides a paradigm to determine which of the two strategies (migration or adaptation) will be adopted by mountain riparian plants under climate warming.

Surviving in Mountain Climate Refugia: New Insights from the Genetic Diversity and Structure of the Relict Shrub Myrtus nivellei (Myrtaceae) in the Sahara Desert

Migliore, Jérémy; Baumel, Alex; Juin, Marianick; Fady, Bruno; Roig, Anne; Duong, Nathalie; Médail, Frédéric
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 18/09/2013 EN
Relevância na Pesquisa
26.41%
The identification of past glacial refugia has become a key topic for conservation under environmental change, since they contribute importantly to shaping current patterns of biodiversity. However, little attention has been paid so far to interglacial refugia despite their key role for the survival of relict species currently occurring in climate refugia. Here, we focus on the genetic consequences of range contraction on the relict populations of the evergreen shrub Myrtus nivellei, endemic in the Saharan mountains since at least the end of the last Green Sahara period, around 5.5 ka B.P. Multilocus genotypes (nuclear microsatellites and AFLP) were obtained from 215 individuals collected from 23 wadis (temporary rivers) in the three main mountain ranges in southern Algeria (the Hoggar, Tassili n’Ajjer and Tassili n’Immidir ranges). Identical genotypes were found in several plants growing far apart within the same wadis, a pattern taken as evidence of clonality. Multivariate analyses and Bayesian clustering revealed that genetic diversity was mainly structured among the mountain ranges, while low isolation by distance was observed within each mountain range. The range contraction induced by the last episode of aridification has likely increased the genetic isolation of the populations of M. nivellei...

Influence of Introgression and Geological Processes on Phylogenetic Relationships of Western North American Mountain Suckers (Pantosteus, Catostomidae)

Unmack, Peter J.; Dowling, Thomas E.; Laitinen, Nina J.; Secor, Carol L.; Mayden, Richard L.; Shiozawa, Dennis K.; Smith, Gerald R.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 11/03/2014 EN
Relevância na Pesquisa
26.34%
Intense geological activity caused major topographic changes in Western North America over the past 15 million years. Major rivers here are composites of different ancient rivers, resulting in isolation and mixing episodes between river basins over time. This history influenced the diversification of most of the aquatic fauna. The genus Pantosteus is one of several clades centered in this tectonically active region. The eight recognized Pantosteus species are widespread and common across southwestern Canada, western USA and into northern Mexico. They are typically found in medium gradient, middle-elevation reaches of rivers over rocky substrates. This study (1) compares molecular data with morphological and paleontological data for proposed species of Pantosteus, (2) tests hypotheses of their monophyly, (3) uses these data for phylogenetic inferences of sister-group relationships, and (4) estimates timing of divergence events of identified lineages. Using 8055 base pairs from mitochondrial DNA protein coding genes, Pantosteus and Catostomus are reciprocally monophyletic, in contrast with morphological data. The only exception to a monophyletic Pantosteus is P. columbianus whose mtDNA is closely aligned with C. tahoensis because of introgression. Within Pantosteus...

A rocky mountain stream in Saint Andrews, Jamaica; The Bryant Slides Collection; The Bryant Slides Collection, Jamaica

Unknown ( Photographer )
Fonte: Universidade da Flórida Publicador: Universidade da Flórida
Tipo: still image Formato: 35 mm
Relevância na Pesquisa
36.24%
The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location.; Trees and a rocky stream near the Blue Mountain Inn in Gordon Town, Saint Andrews, Jamaica. Slide labeled Blue Mt Inn.

Mountain view and stream in Portland, Jamaica; The Bryant Slides Collection; The Bryant Slides Collection, Jamaica

Unknown ( Photographer )
Fonte: Universidade da Flórida Publicador: Universidade da Flórida
Tipo: still image Formato: 35 mm
Relevância na Pesquisa
36.24%
The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location.; View across the river of a house among trees on the mountain side in Portland, Jamaica. Slide labeled Jam. on road to Moore Town.

Houses in a rural mountain region of Saint Vincent; The Bryant Slides Collection; The Bryant Slides Collection, Saint Vincent

Unknown ( Photographer )
Fonte: Universidade da Flórida Publicador: Universidade da Flórida
Tipo: still image Formato: 35 mm
Relevância na Pesquisa
36.35%
The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location.; Houses, some built on stilts, located in a rural mountain region of Saint Vincent. A winding rocky stream is flowing along the mountain side. The stone foundations of some buildings and electric poles are visible.

Estudo da resistência ao escoamento em canais de fundo fixo.; Flow resistance estimation in open channels with rigid bed.

Romero Suárez, Yannick Vália
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 16/03/2001 PT
Relevância na Pesquisa
46.81%
O problema da previsão da resistência ao escoamento em canais tem atraído a atenção dos engenheiros há longo tempo. Durante os últimos decênios a resistência ao escoamento em canais abertos de fundo fixo tem sido amplamente investigada, usando rugosidade artificial nas superfícies de canais experimentais. A adoção do coeficiente de rugosidade para um canal natural significa estimar a resistência de este ao escoamento. A utilização de um valor incorreto deste coeficiente pode ter grandes impactos na estimação da vazão e em conseqüência no dimensionamento dos projetos de obras hidráulicas. Apresenta-se, mediante pesquisa bibliográfica, os métodos de cálculo para avaliação do coeficiente de rugosidade ou coeficiente de resistência, dando ênfase a aqueles desenvolvidos para canais naturais com rugosidade de grande escala, sem os efeitos do transporte de sedimentos. Em modelo físico avaliam-se os efeitos da distribuição, tamanho e forma dos elementos geométricos na resistência ao escoamento. Espera-se que os resultados da pesquisa proporcionem ao engenheiro os critérios necessários para a avaliação do coeficiente de rugosidade. Os métodos diretos de medição de vazões nos rios nem sempre podem ser levados a cabo em rios de montanha ...

Abundance, feeding and reproduction of Salminus sp. (Pisces: Characidae) from mountain streams of the Andean piedmont in Venezuela

Rodríguez-Olarte,Douglas; Taphorn B.,Donald C.
Fonte: Sociedade Brasileira de Ictiologia Publicador: Sociedade Brasileira de Ictiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2006 EN
Relevância na Pesquisa
26.4%
To obtain basic information for management, aspects of the ecology of Salminus sp. (Pisces: Characidae), were studied in piedmont rivers of the southwestern flank of the Andes in Venezuela. Collections were made with seines of various lengths and mesh sizes, and both underwater and terrestrial observations were recorded to estimate abundance and feeding events. Interviews with local fishermen and inhabitants were made to obtain data on use. The species is present along the entire length of the Andean piedmont in Venezuela, although in some rivers it is now scarce. Small individuals form mixed schools with Brycon whitei, but larger Salminus sp. usually only school with others of the same species. Average abundance was greater in larger rivers, and didn't vary appreciably with season for any of the rivers studied. Size and weight ranged from 15.1 to 40.5 cm SL and 47.7 to 1,210 g, respectively. Females had maximum ovary maturity at the beginning of the rainy season, with an average fecundity of 35,834 eggs, and spawning occurred during spates of high water. Feeding was crepuscular, with most events recorded during the first and last hours of sunlight. In smaller fish up to 20 cm SL, the diet was varied, but above that size fish were the principal food item. Salminus sp. has little commercial importance in this region but forms an important part of the local subsistence fishery...

Seasonal moisture sources and the isotopic composition of precipitation, rivers, and carbonates across the Andes at 32.5–35.5

Viale, Maximiliano; Aranibar, Julieta N.; Llano, Carina; Araneo, Diego C.; Hoke, Gregory D.
Fonte: American Geophysical Union Publicador: American Geophysical Union
Tipo: Artículo de revista
EN
Relevância na Pesquisa
26.34%
Artículo de publicación ISI; Constraining the influence of different moisture sources across the flanks of mountain ranges is important for understanding tectonic, geomorphic, and paleoclimate problems at geologic timescales, as well as evaluating climate change and water resources on human time scales. The stable isotope compositions of stream waters and precipitation are an ideal tool for this task. This study reports the results of a 2 year monthly precipitation sampling campaign on the eastern flank of the Andes in the Mendoza Province of Argentina, which began in September 2008. A total of 104 precipitation samples spanning some 2500m of relief from nine sites were analyzed for dD and d18O. In addition, 81 samples from Andean rivers collected on both sides of the range in 2002 and 2007 were analyzed. We employ a Rayleigh isotope fractionation modeling approach to explore spatial and temporal variations in precipitation and river water compositions. The results indicate that precipitation on the eastern slopes of the Andes at ~33 S, at elevations above 2 km, is largely derived from a westerly, Pacific-source component and a mixture of easterly and westerly sources below 2 km. Further south at ~35 S, river water compositions exhibit a strong winter influence. At 33 S...

Complexity analysis of the turbulent environmental fluid flow time series

Mihailovic, Dragutin T.; Nikolic-Djoric, Emilija; Dreskovic, Nusret; Mimic, Gordan
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.71%
We have used the Kolmogorov complexities, sample and permutation entropies to quantify the randomness degree in river flow time series of two mountain rivers in Bosnia and Herzegovina, representing the turbulent environmental fluid, for the period 1926-1990. In particular, we have examined the monthly river flow time series from two rivers (Miljacka and Bosnia) in mountain part of their flow and then calculated the Kolmogorov Complexity (KL) based on the Lempel-Ziv Algorithm (LZA) (Lower - KLL and Upper - KLU), Sample Entropy (SE) and Permutation Entropy (PE) values for each time series. The results indicate that the KLL, KLU, SE and PE values in two rivers are close to each other regardless of the amplitude differences in their monthly flow rates. We have illustrated the changes in mountain river flow complexity by experiments using (i) the data set for the Bosnia River and (ii) anticipated human activities and projected climate changes. We have explored the sensitivity of considered measures in dependence on the length of time series. In addition, we have divided the period 1926-1990 into three sub-intervals: (a) 1926-1945, (b)1946-1965 and (c)1966-1990, and calculated the KLL, KLU, SE and PE values for the various time series in these sub-intervals. It is found that during the period 1946-1965...

Evidencias geomorfológicas de actividad tectónica cuaternaria en el frente montañoso del borde sur de Sierra Nevada: la falla normal de Laujar de Andarax.; Geomorphologycal evidences of activity quaternary in the mountain front of the south border of Sierra Nevada. The normal fault of Laujar de Andarax

Sanz de Galdeano, Carlos; García-Tortosa, Francisco Juan
Fonte: Asociación Española para el Estudio del Cuaternario; Sociedad Española de Geomorfología Publicador: Asociación Española para el Estudio del Cuaternario; Sociedad Española de Geomorfología
Tipo: Artículo Formato: 1064983 bytes; application/pdf
SPA
Relevância na Pesquisa
36.41%
[ES] En el sector de Laujar de Andarax, en el contacto entre el borde sur de Sierra Nevada y el Corredor de las Alpujarras, existe una zona de falla normal activa que se describe por primera vez en este trabajo. Esta falla, que tiene una dirección media E-O, genera un marcado frente montañoso y afecta a materiales del Pleistoceno superior. El frente montañoso se prolonga hacia el oeste menos conservado debido al fuerte encajamiento de la red fluvial. Por el contrario, el sector de Laujar se encuentra menos afectado por dicho encajamiento al situarse entre la divisoria de los ríos que drenan gran parte del corredor (Adra y Andarax). Esta situación ha permitido la conservación de materiales cuaternarios de piedemonte, pudiéndose observar y cuantificar la deformación en base a las edades asignadas. Los valores de levantamiento estimados para el borde sur de Sierra Nevada estarían comprendidos entre 0,43 y 0,75mm/año.; [EN] In the sector of Laujar of Andarax, in the contact of the south border Sierra Nevada and the Alpujarran corridor, an active normal fault exists, now described for the first time in this work. This fault, with an E-W direction, generates a marked mountain front and affects to upper Pleistocene sediments. This mountain front is prolonged toward the west...

Drainage reorganization during mountain building in the river system of the Eastern Cordillera of the Colombian Andes

Struth, Lucía; Babault, Julien; Teixell Cácharo, Antonio
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/submittedVersion Formato: application/pdf
Publicado em //2015 ENG
Relevância na Pesquisa
26.54%
The Eastern Cordillera of Colombia is a thick-skinned thrust-fold belt that is characterized by two topographic domains: (1) the axial zone, a high altitude plateau (the Sabana de Bogotá, 2500 masl) with low local relief and dominated by longitudinal rivers, and (2) the Cordillera flanks, where local relief exceeds 1000 m and transverse rivers dominate. On the basis of an analysis of digital topography and river parameters combined with a review of paleodrainage data, we show that the accumulation of shortening and crustal thickening during the Andean orogeny triggered a process of fluvial reorganization in the Cordillera. Owing to a progressive increase of the regional slope, the drainage network evolves from longitudinal to transverse-dominated, a process that is still active at present. This study provides the idea of progressive divide migration toward the inner part of the mountain belt, by which the area of the Sabana de Bogotá plateau is decreasing, the flanks increase in area, and ultimately transverse rivers will probably dominate the drainage of the Cordillera.

Decadal carbon discharge by a mountain stream is dominated by coarse organic matter

Turowski, Jens M.; Hilton, Robert G.; Sparkes, Robert
Fonte: Geological Society of America Publicador: Geological Society of America
Tipo: Article; published version
EN
Relevância na Pesquisa
26.54%
This is the final version of the article. It was first available from Geological Society of America via http://dx.doi.org/10.1130/G37192.1; Rapid erosion in mountain forests results in high rates of biospheric particulate organic carbon (POC) export by rivers, which can contribute to atmospheric carbon dioxide drawdown. However, coarse POC (CPOC) carried by particles larger than ~1 mm is rarely quantified. In a forested pre-Alpine catchment, we measured CPOC transport rates and found that they increase more rapidly with water discharge than fine POC (<1mm) and dissolved organic carbon (DOC). As a result, decadal estimates of CPOC yield of 12.3?1.9 tC km??yr?? are higher than for fine POC and DOC, even when excluding 4 extreme flood events. When including these floods, CPOC dominates organic carbon discharge (~80%). Most CPOC (69%) was water-logged and denser than water, suggesting CPOC has the potential to contribute to long-term sedimentary burial. Global fluxes remain poorly constrained, but if the transport behavior of CPOC shown here is common to other mountain streams and rivers then neglecting CPOC discharge could lead to a large underestimation of the global transfer of biospheric POC from land to ocean.; This study was supported by SNF grant 200021_124634/1...

Particle friction angles in steep mountain channels

Prancevic, Jeff P.; Lamb, Michael P.
Fonte: American Geophysical Union Publicador: American Geophysical Union
Tipo: Article; PeerReviewed Formato: application/pdf; application/msword; text/plain; text/plain; text/plain; text/plain; text/plain; text/plain; text/plain; text/plain; text/plain
Publicado em /02/2015
Relevância na Pesquisa
26.49%
Sediment transport rates in steep mountain channels are typically an order of magnitude lower than predicted by models developed for lowland rivers. One hypothesis for this observation is that particles are more stable in mountain channels due to particle-particle interlocking or bridging across the channel width. This hypothesis has yet to be tested, however, because we lack direct measurements of particle friction angles in steep mountain channels. Here we address this data gap by directly measuring the minimum force required to dislodge sediment (pebbles to boulders) and the sediment weight in mountain channels using a handheld force gauge. At eight sites in California, with reach-averaged bed angles ranging from 0.5° to 23° and channel widths ranging from 2 m to 16 m, we show that friction angles in natural streams average 68° and are 16° larger than those typically measured in laboratory experiments, which is likely due to particle interlocking and burial. Results also show that larger grains are disproportionately more stable than predicted by existing models and that grains organized into steps are twice as stable as grains outside of steps. However, the mean particle friction angle does not vary systematically with bed slope. These results do not support systematic increases in friction angle in steeper and narrower channels to explain the observed low sediment transport rates in mountain channels. Instead...

Predominance of Grenvillian Magmatism Recorded in Detrital Zircons from Modern Appalachian Rivers

Eriksson, Kjell; Campbell, Ian; Palin, J M; Allen, Charlotte M
Fonte: University of Chicago Press Publicador: University of Chicago Press
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.34%
Detrital zircons from six modern rivers draining the Appalachian Mountains were dated using U-Pb isotopes measured by excimer laser ablation induction coupled plasma-mass spectrometry (ELA-ICP-MS). Of the 905 grains analyzed, 736 were acceptable for age determination and 524 (71%) of these yielded ages between 950 and 1250 Ma, defining a continuous Grenvillian tectonomagmatic event that peaked around 1020-1050 Ma. Of the remaining zircons, 20% (n = 149) have Paleozoic ages corresponding mainly with the Taconian (430-500 Ma) and Acadian (350-400 Ma) orogenies. The overwhelming dominance of Grenvillian zircons in rivers draining the Appalachian Mountains implies the former existence of a mountain belt whose detritus has dominated the sedimentary record for the past 1.0 billion years in eastern North America and beyond. In the zircon age spectra, which are a measure of the intensity of crustal melting associated with an orogeny, the Grenvillian dwarfs the collective Paleozoic orogenies in the Appalachians and therefore was the most important tectonomagmatic event to affect eastern North America.

Book review: Land of the seven rivers: a brief history of India’s geography

St John, Ian
Fonte: London School of Economics and Political Science Publicador: London School of Economics and Political Science
Tipo: Website; NonPeerReviewed Formato: application/pdf
Publicado em 07/03/2013 EN; EN
Relevância na Pesquisa
26.34%
Sanjeev Sanyal sets off to explore India and look at how the country’s history was shaped by its rivers, mountains and cities. He traverses remote mountain passes, visits ancient archaeological sites, crosses rivers in shaky boats and immerses himself in old records and manuscripts. Ian St John thinks this is a book more for the general reader or traveller looking for an engaging but not overly demanding introduction to the historical background to contemporary India.

Groundwater discharges to aquatic ecosystems associated with the Table Mountain Group (TMG) aquifer: A conceptual model

Roets,W; Xu,Y; Raitt,L; Brendonck,L
Fonte: Water SA Publicador: Water SA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
Relevância na Pesquisa
26.54%
This paper reports on a conceptual model that was developed to describe the different groundwater discharge 'types' from the Table Mountain Group (TMG) aquifer, that contributes to the different components of the flow regime in each of the recognised river reaches for streams and rivers associated with the TMG. This model integrates hydrogeological, ecological and geomorphological understandings into an ecohydrological perspective linking ground- and surface water systems. Through geospatial intersections of existing GIS layers a GIS model was also developed to highlight the quaternary catchments containing sensitive aquatic ecosystems that could be vulnerable to groundwater use from the TMG. The conceptual model demonstrates the intimate link between groundwater from the TMG aquifer and aquatic ecosystems in the mountain and foothill reaches of streams and rivers in the Cape Folded Mountains in particular. It also identifies two primary zones of interaction between groundwater and surface water in the TMG, namely, the 'TMG aquifer daylight-domain', located in the recharge zone, and the 'TMG aquifer surface water interface-domain', located at the discharge end of the aquifer. The conceptual model clearly indicates the difference between real groundwater...