• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 2
  • 1
  • Tagged with
  • 5
  • 4
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Faktory ovlivňující přežívání bolena dravého (\kur{Aspius aspius}) a candáta obecného (\kur{Sander lucioperca}) v hluboké kaňonovité nádrži / Factors affecting survival of asp (\kur{Aspius aspius}) and pikeperch (\kur{Sander lucioperca}) in a deep canyon-shaped reservoir

BLABOLIL, Petr January 2012 (has links)
Changes in abundances of 0+, 1+ and 2+ age classes of the two most important piscivorous species - asp (Aspius aspius) and pikeperch (Sander lucioperca) in a deep canyon-shaped reservoir were investigated. A long-term fish sampling in the reservoir including fry trawling, fry and adult beach seining and gillneting was used to determine the factors affecting the recruitment. All data were used in a single linear model and the results obtained using different sampling methods were discussed.
2

Definice referenčního stavu horských a podhorských toků jako součást ekomorfologického průzkumu / Definition of reference conditions of mountain and submountain streams as a part of ecological survey

Leipeltová, Petra January 2014 (has links)
The present thesis deals with the definition of reference conditions of mountain and submountains streams in selected European countries and on the requirements of the Water Framework Directive 2000/60/EC. Here is presented the Typology of watercourses of Czech Republic and the delimitation of mountain and submountains types in selected locations in the Ore Mountains and the Bohemian Forest. In the second part of the work is solved hydromorphological status of watercourses. Monitoring was conducted on streams Rolava, Černá voda, Křemelná, Slatinný p., Modravský p., Roklanský p. and Javoří p. To evaluate the degree of hydromorphological quality was used Hydroecological monitoring method. The thesis includes a brief assessment of physical-geographic characteristics mentioned flows with emphasis on the runoff regime in their basins. In conclusion, there are identified and defined reference parts of streams and their characteristics. Keywords: reference conditions, typology of streams, hydromorphological status, hydromorphological quality, hydromorphological monitoring, runoff regime
3

Gestion des développements d'algues benthiques dans les canaux de transport d'eau : modèles pour des stratégies de régulation hydrauliques / Management of benthic algae developments in open-channel networks : models for hydraulic regulation strategies

Fovet, Ophélie 14 December 2010 (has links)
Les développements d'algues benthiques dans les canaux de transport d'eau induisent d'importantes contraintes pour la gestion des canaux de distri bution d'eau. Les nuisances physiques et chimiques associées à ces développements nécessitent des stratégies de gestion alternatives. La thèse étudie des méthodes pour la gestion de ces populations algale basées sur le contrôle hydraulique du système: les chasses hydrauliques. Ces opérations consistent à détacher une partie de la biomasse algale fixée en augmentant les contraintes de cisaillement exercées par le courant sur ces algues fixées au substrat. Leur remise en suspension, entraînant un pic de turbidité, doit également être maîtrisée. L'approche proposée vise à caractériser et modéliser les processus de développement, de détachement et de transport des algues lors de ces chasses hydrauliques. Des suivis expérimentaux de la croissance sont réalisés en mésocosme (à l'échelle de canaux réduits). Les suivis de biomasse permettent de caler un modèle de croissance de la couverture algale intégrant l'effet de l'hydrodynamique et de la s ensibilité des algues aux perturbations hydrodynamiques. Des stratégies de chasses sont ensuite expérimentées sur deux canaux de distribution d'eau en zone méditérannéenne. Un modèle de la dynamique des algues fixées et en dérive en réponse à une chasse hydraulique est ensuite élaboré sur la base de ces expérimentations, et calé sur les nuages de turbidité observés. Finalement, un cadre méthodologique basé sur un modèle linéaire est proposé pour des applications à la gestion en temps réel d'une variable de qualité : la turbidité. Deux approches de contrôle sont présentées : la commande en boucle ouverte et la commande adaptative qui permet de recaler les paramètres inconnus comme la biomasse initiale. / Algae developments in open-channel networks induce strong constraints for the network management. The physical and chemical nuisances linked to these developments require alternative management strategies. The thesis proposes an original method for these algae management based on the hydraulic control of the system using flushing-flows. These flushes consist in detaching a part of the fixed algae by increasing the hydraulic shear stress exerted on the biomass fixed on the substratum. The re-suspension of algae in the water column induces a turbidity peak which also has to be controlled. The proposed approach aims at characterizing and modelling the processes of algae development, detachment and transport during the flushes. Experimental monitoring of the growth phase is conducted in experimental flumes. The biomass samples are used to calibrate a model of algal growth which integrates the hydrodynamic effect and the algae sensitivity in the Med iterranean region. A model of the fixed and drift algae dynamics in response to a flush is then developed and calibrated on the observerd turbidity plumes. Finally, a control framework based on a linear model is proposed for the turbidity control during a flush. An open-loop control is first developed, then an adaptative feedback controller is tested to estimate unknown parameters such as initial biomass.
4

Monitoramento da qualidade da água do Rio Grande Bacia do Rio Paraíba do Sul / Monitoring of water quality in the Rio Grande - Paraíba River Basin South

Leão, Marina Mendonça 22 February 2011 (has links)
Made available in DSpace on 2015-03-26T13:28:02Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1211971 bytes, checksum: 0f6618d19ac83222d911f8105b6a9ec9 (MD5) Previous issue date: 2011-02-22 / The assessment of water quality in the Rio Grande, a tributary basin of the Paraíba do Sul, was performed by monitoring physical-chemical, microbiological and hydrobiological parameters to check their correlation with changes in the diversity of habitats and microhabitats and determine the impact of modification of water quality on biological communities in the future. Monitoring physical, chemical and biological water was conducted at eleven points in Bom Jardim, São Sebastião do Alto and Santa Maria Madalena (RJ) in eight collection campaigns in the months of June, August and December 2008, May, April , July and October 2009 and January 2010. The parameters analyzed include metals (arsenic, barium, cadmium, lead, copper, chromium, mercury and zinc), phenols, dissolved oxygen, fecal coliforms, pH, biochemical oxygen demand, total nitrogen, ammonia, nitrites, nitrates, total phosphorus, temperature, turbidity, total solids and phytoplankton, zooplankton and zoobenton. Collections and analyses were performed according to Standard Methods for the Examination of Water and Wastewater (APHA, 2005). The data was converted to quality indexes - water quality index (WQI), toxicity index (TI), trophic state index (TSI), index of water quality for protection of aquatic life and aquatic communities (LAI) and Shannon-Wiener index (H'). Examination of the and relationships among variables and indices showed that while the WQI and LAI consistently pointed to good water quality, the biological indices indicated poor water quality. It was also verified that at points where there were higher concentrations of toxic substances, phosphorus and organic matter, non-tolerant species were absent from the hydrobiological communities (phytoplankton, zooplankton and zoobenton), suggesting contamination by industrial wastes. / A avaliação da qualidade da água do Rio Grande, afluente da bacia do Rio Paraíba do Sul, foi realizada através do monitoramento de parâmetros físicos e químicos, microbiológicos e hidrobiológicos para verificar sua correlação com alterações na diversidade de habitats e microhabitats e determinar o impacto da modificação da qualidade de água sobre as comunidades biológicas. O monitoramento da qualidade da água foi realizado em onze pontos nos municípios de Bom Jardim, São Sebastião do Alto e Santa Maria Madalena (RJ) em oito campanhas de coleta nos meses de junho, agosto e dezembro de 2008; maio, abril, julho e outubro de 2009 e janeiro de 2010. Os parâmetros quantificados incluem metais (arsênio, bário, cádmio, chumbo, cobre, cromo, mercúrio e zinco), fenóis, oxigênio dissolvido, coliformes termotolerantes, pH, demanda bioquímica de oxigênio, nitrogênio total, amônia, nitritos, nitratos, fósforo total, temperatura, turbidez, sólidos totais e fitoplâncton, zooplâncton e zoobenton. As coletas das amostras e as análises físicas e químicas, microbiológicas e hidrobiológicas foram realizadas conforme os procedimentos dispostos no Standard Methods for the Examination of Water and Wastewater (APHA, 2005). Os dados gerados foram convertidos em índices de qualidade índice de qualidade da água (IQA), índice de toxicidade (IT), Índice do Estado Trófico (IET), Índices de Qualidade das Águas para Proteção da Vida Aquática e de Comunidades Aquáticas (IVA) e índice Shannon-Wiener (H ) sendo realizada a interpretação das variáveis individuais e a relação com os demais. Enquanto IQA e IVA apontontaram para qualidade regular a ótima durante o período e monitoramento, os índices biológicas apontaram para qualidade de ruim a péssimo na maioria do tempo. Foi possível verificar que nos pontos onde foram observados maiores concentrações de substâncias tóxicas, fósforo e matéria orgânica, houve ausência de espécies não tolerantes e presença de espécies tolerantes nas comunidades hidrobiológicas (fitoplâncton, zooplâncton e zoobenton), evidenciando efeitos de contaminação por despejos industriais.
5

Extraction d'informations synthétiques à partir de données séquentielles : application à l'évaluation de la qualité des rivières / Extraction of synthetic information from sequential data : application to river quality assessment

Fabregue, Mickael 26 November 2014 (has links)
L'exploration des bases de données temporelles à l'aide de méthodes de fouille de données adaptées a fait l'objet de nombreux travaux de recherche. Cependant le volume d'informations extraites est souvent important et la tâche d'analyse reste alors difficile. Dans cette thèse, nous présentons des méthodes pour synthétiser et filtrer l'information extraite. L'objectif est de restituer des résultats qui soient interprétables. Pour cela, nous avons exploité la notion de séquence partiellement ordonnée et nous proposons (1) un algorithme qui extrait l'ensemble des motifs partiellement ordonnés clos; (2) un post-traitement pour filtrer un ensemble de motifs d'intérêt et(3) une approche qui extrait un consensus comme alternative à l'extraction de motifs. Les méthodes proposées ont été testées sur des données hydrobiologiques issues du projet ANR Fresqueau et elles ont été implantées dans un logiciel de visualisation destiné aux hydrobiologistes pour l'analyse de la qualité des cours d'eau. / Exploring temporal databases with suitable data mining methods have been the subject of several studies. However, it often leads to an excessive volume of extracted information and the analysis is difficult for the user. We addressed this issue and we specically focused on methods that synthesize and filter extracted information. The objective is to provide interpretable results for humans. Thus, we relied on the notion of partially ordered sequence and we proposed (1) an algorithm that extracts the set of closed partially ordered patterns ; (2) a post-processing to filter some interesting patterns for the user and (3) an approach that extracts a partially ordered consensus as an alternative to pattern extraction. The proposed methods were applied for validation on hydrobiological data from the Fresqueau ANR project. In addition, they have been implemented in a visualization tool designed for hydrobiologists for water course quality analysis.

Page generated in 0.0441 seconds