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Urbanização na planície de inundação do Rio Gravataí - RSScheren, Rudimar Schuster January 2014 (has links)
O avanço da urbanização sobre as planícies de inundação causa impactos no ciclo hidrológico, na sedimentação e nas funções hidrológicas dos rios. Na planície fluvial do rio Gravataí os eventos de urbanização contribuíram para a redução da sua área inundável. Esse avanço da urbanização está associado à obras de engenharia que funcionam como barragens, que evitam que a água ocupe a planície fluvial em períodos de cheia. O presente estudo espacializa essa redução da área inundável da planície de inundação do rio Gravataí e as alterações nela recorrentes, a partir do avanço das áreas urbanas de Alvorada, Cachoeirinha, Canoas, Gravataí e Porto Alegre, sobre a planície fluvial. Foi elaborado o mapeamento da planície de inundação do rio Gravataí a partir de mapas geomorfológicos e geológicos; e das áreas inundadas, a partir de imagens do Landsat TM 5 de 10/01/2007 e 20/09/2009, aplicando o índice NDWI - Índice de Água por Diferença Normalizada - para definir o limite de inundação atual. Os dados obtidos foram comparados com um mapa das inundações da década de 1970. Também foi mapeada a expansão dos municípios analisados, nos anos de 1975, 1984 e 2009, e analisadas: A evolução urbana sobre a planície de inundação, a redução espacial das áreas inundáveis e os limites atingidos pela inundação. Os principais resultados mostram que as áreas urbanas dos cinco municípios cresceram consideravelmente sobre a planície de inundação do rio Gravataí, enquanto os limites de inundação foram reduzidos. A área inundável recuou consideravelmente em comparação ao seu alcance natural, pois os diques construídos para conter as cheias alteraram os limites de inundação e favoreceram o crescimento urbano. Na comparação entre as áreas ocorreu uma significativa expansão urbana, enquanto que inversamente, a área inundável apresentou redução espacial. Em 1975 a área de mancha urbana era de 75 Km², já em 2009 de 183 Km². A área inundável na década de 1970 tinha 58 Km², e em 2009 33 Km². As áreas urbanas na planície de inundação ocupavam 33 Km² em 1975, e em 2009 67 Km². / The advancement of urbanization on flood plains has been cause impacts on the water cycle, sedimentation and hydrological functions of the rivers . In the fluvial plain of the river Gravataí events urbanization contributed to the reduction of its flood area. This advance of urbanization is associated with engineering works that act as dams that prevent water occupy the plain river in flood season. This study spatializes this reduction of flood area in the floodplain river Gravataí and amendments thereto applicants from the advance of urban areas Alvorada , Cachoeirinha, Canoas , Gravataí and Porto Alegre, on the river plain. Was developed mapping of the floodplain of the river Gravataí from geomorphological and geological maps , and flooded areas from Landsat TM 5 of 10/01/2007 and 20/09/2009, applying the index NDWI - Water Index Normalized Difference - to set the limit of current flood . The data obtained were compared with a map of the floods of the 1970s. Was also mapped the expansion of the cities analyzed in the years 1975, 1984 and 2009 and analyzed: The urban development on the flood plain, the spatial reduction of the flood area and the limits reached by the flood. The main results show that urban areas of five counties grew considerably over the floodplain of the river Gravataí, while the flood limits were reduced. The flood area decreased considerably compared to their natural range because the levees built to contain the flood changed the limits of flooding and favored urban growth. Comparing the areas was a significant urban expansion, while conversely, the flood area was reduced space. In 1975 the urban area was 75 square kilometers, in 2009 of 183 Km². The flooded area in the 1970s was 58 Km ² and 33 Km ² in 2009. Urban areas in the floodplain occupied 33 Km ² in 1975 , and in 2009 67 Km ².
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Urbanização na planície de inundação do Rio Gravataí - RSScheren, Rudimar Schuster January 2014 (has links)
O avanço da urbanização sobre as planícies de inundação causa impactos no ciclo hidrológico, na sedimentação e nas funções hidrológicas dos rios. Na planície fluvial do rio Gravataí os eventos de urbanização contribuíram para a redução da sua área inundável. Esse avanço da urbanização está associado à obras de engenharia que funcionam como barragens, que evitam que a água ocupe a planície fluvial em períodos de cheia. O presente estudo espacializa essa redução da área inundável da planície de inundação do rio Gravataí e as alterações nela recorrentes, a partir do avanço das áreas urbanas de Alvorada, Cachoeirinha, Canoas, Gravataí e Porto Alegre, sobre a planície fluvial. Foi elaborado o mapeamento da planície de inundação do rio Gravataí a partir de mapas geomorfológicos e geológicos; e das áreas inundadas, a partir de imagens do Landsat TM 5 de 10/01/2007 e 20/09/2009, aplicando o índice NDWI - Índice de Água por Diferença Normalizada - para definir o limite de inundação atual. Os dados obtidos foram comparados com um mapa das inundações da década de 1970. Também foi mapeada a expansão dos municípios analisados, nos anos de 1975, 1984 e 2009, e analisadas: A evolução urbana sobre a planície de inundação, a redução espacial das áreas inundáveis e os limites atingidos pela inundação. Os principais resultados mostram que as áreas urbanas dos cinco municípios cresceram consideravelmente sobre a planície de inundação do rio Gravataí, enquanto os limites de inundação foram reduzidos. A área inundável recuou consideravelmente em comparação ao seu alcance natural, pois os diques construídos para conter as cheias alteraram os limites de inundação e favoreceram o crescimento urbano. Na comparação entre as áreas ocorreu uma significativa expansão urbana, enquanto que inversamente, a área inundável apresentou redução espacial. Em 1975 a área de mancha urbana era de 75 Km², já em 2009 de 183 Km². A área inundável na década de 1970 tinha 58 Km², e em 2009 33 Km². As áreas urbanas na planície de inundação ocupavam 33 Km² em 1975, e em 2009 67 Km². / The advancement of urbanization on flood plains has been cause impacts on the water cycle, sedimentation and hydrological functions of the rivers . In the fluvial plain of the river Gravataí events urbanization contributed to the reduction of its flood area. This advance of urbanization is associated with engineering works that act as dams that prevent water occupy the plain river in flood season. This study spatializes this reduction of flood area in the floodplain river Gravataí and amendments thereto applicants from the advance of urban areas Alvorada , Cachoeirinha, Canoas , Gravataí and Porto Alegre, on the river plain. Was developed mapping of the floodplain of the river Gravataí from geomorphological and geological maps , and flooded areas from Landsat TM 5 of 10/01/2007 and 20/09/2009, applying the index NDWI - Water Index Normalized Difference - to set the limit of current flood . The data obtained were compared with a map of the floods of the 1970s. Was also mapped the expansion of the cities analyzed in the years 1975, 1984 and 2009 and analyzed: The urban development on the flood plain, the spatial reduction of the flood area and the limits reached by the flood. The main results show that urban areas of five counties grew considerably over the floodplain of the river Gravataí, while the flood limits were reduced. The flood area decreased considerably compared to their natural range because the levees built to contain the flood changed the limits of flooding and favored urban growth. Comparing the areas was a significant urban expansion, while conversely, the flood area was reduced space. In 1975 the urban area was 75 square kilometers, in 2009 of 183 Km². The flooded area in the 1970s was 58 Km ² and 33 Km ² in 2009. Urban areas in the floodplain occupied 33 Km ² in 1975 , and in 2009 67 Km ².
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Grupos substitutos, correspondência de assembléias aquáticas em relação a esquemas de classificação regional, e determinantes de diversidade beta em uma planície de inundação neotropical / Groups substitutes, matching assemblies waterfowl in relation to regional classification schemes, and determinants of beta diversity in a floodplain neotropical floodPADIAL, André Andrian 25 January 2010 (has links)
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Previous issue date: 2010-01-25 / A general goal in community ecology is to understand how communities are
organized in space and time. An aspect of great interest is to evaluate how concordant
are the patterns of beta diversity depicted by different biological groups. If two
taxonomic groups present a similar spatial/temporal structure, only one of these groups
can be used as a surrogate group in conservation efforts or bioassessments. Also, a
strong correspondence between biological groups and physical classifications of the
habitat could help us to understand the reasons for spatial organization of communities.
Moreover, if communities respond to a priori classifications based on geological and
environmental features of the habitats, the selection of priority areas for conservation
distributed on the classes of a classification scheme could maximize the conservation of
overall biodiversity. Finally, to understand the main processes driving the organization
of communities, the relative role of different set of predictor variables can be
simultaneously evaluated. If species compositions are mainly predicted by
environmental variables then one can conclude that species sorting mechanisms are the
main drivers of community structure. On the other hand, if variables that represent
spatial structure of the environments are the main predictors of variation in species
composition, then neutral processes may be invoked to explain the structure of the
biological group under analysis. Therefore, the main goals of this thesis are: (i) to
evaluate the concordance among distinct biological groups; (ii) to evaluate the
correspondence between a priori physical classifications of the habitat and the
composition of assemblages and; (iii) to evaluate the relative role of environmental and
spatial predictors on the structure of local assemblages in a Neotropical floodplain. For
that, we used data sets on six biological groups (fish, benthic macroinvertebrates,
aquatic macrophytes, zooplankton, phytoplankton, and periphyton) which were gathered
during 2000 and 2001 in up to 36 aquatic environments of the Upper Paraná River
floodplain. Patterns of assemblage concordance were frequently observed. The main
mechanisms responsible for cross-taxon concordance were a similar response to
environmental/spatial gradients and biological interactions between species. The
mechanisms were identified after controlling for the effect of environmental/spatial
variables on the cross-taxon concordance and after evaluating the level of concordance
between species from each group that most likely are linked by biological interactions.
However, the levels of assemblage concordance were weak and varied conspicuously
with time. These results highlight that the use of surrogate groups is a flawed strategy to support conservation efforts in the Upper Paraná River floodplain. Nevertheless, the
classification scheme of the floodplain, considering mainly limnological and geological
aspects, was efficient to represent the structure of different aquatic assemblages. Thus,
conservation efforts and bioassessments of the aquatic flora and fauna can use this
classification scheme. However, the temporal variability also affected the consistency of
the correspondence and this issue should be further investigated. On the other hand,
temporal variables were not effective in predicting the structure of different biological
assemblages. Environmental and spatial variables were generally more important, but
also with low predictive power. Spatial variables were particularly important for large
organisms with low dispersal ability, such as sedentary fish and aquatic plants. On the
other hand, compared to spatial predictors, environmental variables were more
important to explain the structure of small-bodied organisms with high dispersal ability
(such as micro-algae) and organisms with migratory behavior. Nevertheless, all
variables had a low predictive power, probably due to the low extent of the
environmental and spatial gradients and to the lack of variables that represent relevant
processes for determining the structure of aquatic assemblages in floodplains. / Um objetivo geral em Ecologia é entender como as comunidades estão
organizadas no espaço e no tempo. Um aspecto de grande interesse para conservação é
avaliar as similaridades na estrutura espacial e temporal da composição de diferentes
grupos biológicos que habitam um mesmo ecossistema. Utilizando a abordagem de
grupos substitutos, se dois grupos biológicos apresentam estrutura espacial/temporal
similar, apenas um desses grupos concordantes poderia ser avaliado em esforços de
conservação ou biomonitoramento. A correspondência de comunidades a esquemas de
classificação física dos ecossistemas também auxilia o entendimento das razões para a
organização espacial das comunidades. Além disso, se as comunidades respondem a
classificações baseadas, por exemplo, em características geológicas e ambientais dos
hábitats, a seleção de prioritárias áreas amplamente distribuídas nas classes de tais
esquemas de classificação pode maximizar a conservação da biodiversidade regional de
um ecossistema. Finalmente, para entender os principais processos que direcionam a
organização das comunidades nos ecossistemas, o papel relativo de diferentes conjuntos
de variáveis preditoras na estrutura de diferentes assembléias de espécies pode ser
avaliado concomitantemente. Se as assembléias são principalmente afetadas por um
conjunto de variáveis ambientais, a conclusão que se chega é que os principais
mecanismos que controlam as composições das espécies estão relacionados com o nicho
ecológico. Por outro lado, se variáveis que representam as estruturas espaciais dos
ambientes são melhores preditoras, as composições das espécies são determinadas
devido a diferenças em suas capacidades de dispersão. Dessa forma, os objetivos gerais
da presente tese são: (i) avaliar a concordância entre distintos grupos biológicos; (ii)
avaliar a correspondência entre classificações físicas dos ecossistemas e a composição
das assembléias e; (iii) avaliar o papel relativo de diferentes preditores na estrutura das
assembléias em uma planície Neotropical. Para isso, utilizamos dados de seis grupos
biológicos aquáticos (peixes, macroinvertebrados bentônicos, macrófitas aquáticas,
zooplâncton, fitoplâncton e perifíton) coletados trimestralmente durante os anos de 2000
e 2001, em até 36 ambientes da planície de inundação do Alto rio Paraná. Padrões
freqüentes de concordância entre os grupos biológicos foram encontrados. Os
mecanismos mais prováveis para as concordâncias são respostas similares aos
gradientes ambiental e espacial, e interações biológicas entre as espécies. Esses foram
identificados após controlar o efeito das variáveis ambientais e espaciais na
concordância entre dois grupos e ao avaliar a concordância somente entre as espécies dos grupos concordantes que potencialmente são ligadas por interações biológicas.
Entretanto, as magnitudes das correlações entre dois grupos quaisquer foram baixas e
variaram conspicuamente ao longo do tempo. Esses resultados ressaltam que o uso de
grupos substitutos é uma estratégia pouco eficaz para subsidiar esforços de conservação
na planície de inundação do Alto rio Paraná. Entretanto, um esquema de classificação
dessa planície considerando principalmente aspectos limnológicos e geológicos foi
eficaz para representar a estrutura das diferentes grupos biológicos aquáticos. Dessa
forma, ações práticas para conservação da biodiversidade ou para o biomonitoramento
da flora e fauna podem se beneficiar desse esquema de classificação. Porém, a
variabilidade temporal afetou a consistência das classificações, e esse é um aspecto que
deve ser investigado detalhadamente em pesquisas futuras. Por outro lado, variáveis
temporais foram pouco eficazes para predizer a estrutura de composição das diferentes
assembléias na planície de inundação estudada. Apesar de também predizer fracamente
a estrutura das assembléias, as variáveis ambientais e espaciais foram as mais
importantes. Variáveis espaciais foram especialmente importantes para os organismos
com menor capacidade de dispersão, como plantas aquáticas e peixes sedentários. Por
outro lado, o filtro ambiental foi mais importante para explicar a estrutura de
composição de pequenos organismos com alta capacidade de dispersão (como microalgas)
e de organismos com comportamento migratório de reprodução. Entretanto, todas
as variáveis tiveram um baixo poder preditivo, provavelmente devido à baixa extensão
dos gradientes ambiental e espacial e à não inclusão de variáveis que representam
processos importantes para determinar a estrutura das assembléias aquáticas em
planícies de inundação.
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Thresholds and Legacy Effects of Tropical Floodplain Fish Assemblages in Response to Flood AttributesHoeinghaus, Ana Paula Ferrari 12 1900 (has links)
Natural flow regimes are critical for sustaining biodiversity and river integrity. Floods and droughts form an important component of river systems and control population sizes and species diversity across space and time. Modification of flow regimes, including disruption of the timing, magnitude and duration of flooding, is a global problem, and many new impoundments are planned for large river-floodplain ecosystems in the tropics. Flow modifications may cause dramatic non-linear responses in population sizes and have lasting effects through time, but such topics are poorly investigated over multi-year scales, especially in highly diverse tropical ecosystems. Using a long-term dataset from the Upper Paraná River floodplain, Brazil, I tested for threshold and legacy effects of fish assemblages to flood attributes, such as timing, magnitude, duration, rate of change and variation. Specifically, I hypothesized that long duration, high magnitude floods would elicit threshold responses in long-distance migratory fish species and these responses result in significant legacy effects detectable over multiple years. Consistent positive threshold responses to increasing flood duration and magnitude were detected for many species and not significantly correlated with reproductive guilds. Legacy effects were prevalent (i.e. identified for more than 90% of species) and including flood attributes from previous years increased variance explained in species abundances by 15-20% compared to contemporary flood attributes alone. Contrary to my hypotheses, flood duration did not elicit strong legacy effects and species from the same reproductive guild did not have similar legacy effects models. The prevalence of legacy effects across almost all species in this diverse study system highlights the need to consider such dynamics in other systems. My results provide targets for management and conservation actions, such as environmental flow releases from upstream reservoirs. Environmental flows releases may play a significant role in sustainability of the floodplain and other tropical floodplain ecosystems affected by impoundments.
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Diverzita, ekologie a metodika průzkumu lišejníků pralesovitých porostů ve střední Evropě / Diversity, ecology and methods of the research of lichens in old-growth forests in Central EuropeMalíček, Jiří January 2016 (has links)
1 Abstract Forests are the native Central European vegetation, which have dominated in the landscape for the last c. 10,000 years. Stands with an oak and hornbeam dominance occupied lower elevations before human colonization, beech and silver fir-beech forests middle elevations and spruce stands at higher elevations. Only a few remnants of forests, which can be regarded as primeval or with a minimal impact of forest management, have survived in densely populated Central Europe. Examples of the most preserved primeval forests are Rothwald (Austria), Białowieża (Poland, Belorussia), Stužica/Stuzhytsia (Slovakia, Ukraine) and Boubín (Czech Republic). Although these sites are small and isolated, they are local diversity centers for many organisms, mainly for fungi, lichens and bryophytes, refugia for numerous endangered species and some of them have their last localities there. Epiphytic and epixylic lichens are an ideal model group for studies about forests because they sensitively indicate management, continuity, heterogeneity and age of a woodland. Therefore they could help us to answer many important questions about the conservation of natural forests. This thesis comprises several different points of view on lichens in Central European forests and its aim is to join these heterogeneous fields into one...
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Změny využití zemědělské krajiny v širších historických souvislostech na vybraných částech zájmového území Novohradska a Stropnicka. / Land use changes of agricultural landscape in selected areas of Novohradsko and Stropnicko in broader historical context.JIROUŠKOVÁ, Lenka January 2010 (has links)
Changes of land use influence landscape structure, ecological stability, biodiversity and course of biotic and abiotic processes. The intensity of these changes mainly depends on geographic location of the area, land attractiveness and a level of maturity or development of the society. This thesis is focused on evaluation of historical and present changes of land use in Novohradsko and Stropnicko area. This area had in past decades and centuries undergone major landscape changes that are shown on many map sources. These data were elaborated through GIS tools and subsequently analyzed. According to my conclusion, the long- and short-term trends in observed changes of land use have been identified. Since the early 19th Century the arable land area had declined whereas the grasslands had spread out in the studied area. In contrast, recent years resulted in fact that an increase of grass area has stopped which does not coincide with the general effort to grass the LFA.
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Application of Remote Sensing in Floodway DelineationClark, Robin B. 20 April 1974 (has links)
From the Proceedings of the 1974 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 19-20, 1974, Flagstaff, Arizona / Population pressures on the land resources of Arizona have led to the sale and development of areas subject to flooding and because of the inadequacy of land use controls, the area is open to various land speculation schemes and unplanned subdivision growth. A floodplain delineation project was conducted for the planning department of Cochise County, Arizona, in which imagery acquired by earth resources technology satellite (ERT-1) and by high-altitude aircraft was employed. Parameters of the analysis included soils and geomorphology, vegetation, hydrologic calculations, and historical data. Floodplain soils lack developed b horizons, as compared to older, more mature soils not subject to flooding. General soil maps can only be used as guidelines, but a detailed soil survey can add significantly to the accuracy of image interpretations. Erosion-affected soil tones in areas adjacent to active channels proved beneficial in that the heightened contrast served to enhance resolution of vegetation-type boundaries. Hydrologic calculations were done based on valley cross-sections surveyed at two-to-three mile intervals. The historic data input into the system of floodplain delineation is dependent on the location of high-water marks and on obtaining a record of the amount of rainfall which resulted in the high-water mark.
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Braided Stream Sedimentation In The South Saskatchewan RiverCant, Douglas J. 12 1900 (has links)
<p> In the study area, the South Saskatchewan River has a sandy bed (mean diameter .3mm) with irregularly-shaped braid bars termed sand flats. These range in length from 50 to 2000 m. The river has an average discharge of 220m^3/sec, with a mean annual flood of 1450 m^3/sec. The river has been dammed upstream of the study area since 1965, but little downcutting has occured. </p>
<p> Ripples, sand waves and dunes are the equilibrium bedforms present . Ripples and dunes are well known , but sand waves are long , low bedforms with superimposed ripples, lack scour troughs, and occur at lower flow velocities than dunes . Foreset-type bars are also present , but are not equilibrium forms . They result from flow expansion around older topography. They occur at (1) channel junctions, (2) channel bends, (3) areas of channel widening, (4) places of vertical flow expansion . They deposit planar crossbeds. </p> <p> Large areas of the river have many sand flats with no major channels, and may even lack minor channels. These areas are termed sand flat complexes. Where a major channel curves around a sand flat complex, a large diagonal bar is deposited. It is mainly on the tops of these bars where new sand flats form. </p> <p> The major channels rarely exceed 5 m in depth, but may be 150m wide. They are floored by sinuous-crested dunes with sand waves and ripples along their margins. The dunes build up during floods (2 m maximum amplitude). Large dunes occur in the deeper channels. </p> <p> Three different morphologies of small sand flats, symmetric, asymmetric and side, have been recognized. Each type forms from a bar which becomes partly immobilized where it becomes emergent. The remainder of the bar front continues to advance around this emergent nucleus. The different morphologies result because of the control exerted by preexisting deposits on the shape of the initial bar. </p> <p> Larger sand flats lack these morphologies because they have been extensively modified. The major processes of modification are vertical, lateral, and upstream accretion by bars; linking of sand flats by bars; erosional action. The variable morphologies of larger sand flats reflect only their latest modification. The stratification of sand flats is mainly planar crossbed sets deposited by the bars. </p> <p> During the winter, a 60cm thick layer of ice covers the entire system. The sand flats are immobilized because their top layers of sediments are frozen. In some places, their surfaces are disrupted by fluid escape caused by high pore pressures generated by freezing. Flow proceeds down the channels under the ice. Rafting of cobbles and scouring around grounded ice blocks takes place at breakup. </p> <p> The facies sequences resulting from sedimentation in the river are mainly sandy. Those which are deposited by channels consist dominantly of trough crossbeds, but lone planar crossbed sets may be present, deposited by large bars. Facies sequences which include sand flat deposits have several sets of planar crossbeds stacked on top of one another. All sequences have a zone of small crossbeds and ripple cross-lamination near the tops, resulting from shallow water deposition. They are capped by one-half metre of muddy flood-plain deposits. </p> / Thesis / Doctor of Philosophy (PhD)
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The Spatial Relationship Between Septic System Failure and Environmental Factors in Washington Township, Marion County, IndianaHanson, Brian L. 04 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Underground septic systems thrive or fail based on the relationship with their local environment. This paper explores ways environmental variables such as soil type, tree roots, degree of slope, and impervious surfaces affect on-site wastewater treatment systems. It also discusses the effects each of these variables may have on a septic system, and the resulting impact a compromised system may have on the surrounding environment. This research focuses on an approximately 20 square mile area of central Washington Township in Marion County, Indiana. This area of central Indiana contains a large septic system owning population in a sampling of different environments such as wooded areas, hilly areas, and a variety of different soil types.
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