• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • 2
  • 1
  • Tagged with
  • 7
  • 7
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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

Falésias na Formação Barreiras: análise regional e proposta tipológica / Cliffs in Formação Barreiras: regional analysis and typological proposal

Furlan, Adriana Aparecida 22 September 2014 (has links)
As formas naturais do relevo costeiro são resultantes da atuação e interação de processos continentais, oceânicos e atmosféricos. Dentre as diversas feições costeiras destacam-se as falésias e, nesta tese, serão discutidas estas feições esculpidas na Formação Barreiras, sendo esta uma vasta área sedimentar que se estende desde o estado do Rio de Janeiro até o estado do Amapá. Há um grande conjunto de elementos em interação atuando na morfogênese e evolução das falésias e estes são considerados dentro de uma perspectiva de análise sistêmica, sendo estes agrupados e caracterizados como elementos de um Sistema Natural, considerando-se o sistema como um conjunto formado por materiais, processos e formas, tratados, nesta tese, como um sistema geomórfico dinâmico com entrada (inputs) e saída (outputs) de energia e materiais identificáveis, dirigidos e controlados pelas condições ambientais, no qual inúmeros tipos de processos ocorrem simultaneamente. Estudos teóricos e de campo foram realizados em Beberibe-CE, Mucuri-BA e Tibau do Sul-RN e possibilitaram a observação e identificação de características e indícios da morfogênese e evolução das falésias, permitindo a proposição de uma classificação, dentro de um quadro regional da Formação Barreiras, destas feições em: 1) falésia precedida por praia; 2) falésia não precedida por praia. / Natural forms of coastal relief are the result of the action and interaction of continental, oceanic and atmospheric processes. Among various coastal features, cliffs stand out and in this thesis, we discuss these features carved into Formação Barreiras, which is a vast sedimentary area stretching from Rio de Janeiro to Amapá State. There is a large set of elements in interaction taking part in the morphogenesis and in the evolution of cliffs which are considered here within the perspective of a systemic analysis. These elements are classified and characterized as elements of a \"Natural System\", considered system as a whole formed by materials, processes and forms, treated, in this thesis, as a dynamic geomorphic system with inputs and outputs of strenght and materials identifiable, directed and controlled by environmental conditions, in which numberless types of material processes occur simultaneously. Theoretical and field studies performed in Beberibe-CE, Mucuri-BA and Tibau do Sul-RN, allowed us to observe and identify characteristics and evidences of cliffs morphogenesis and evolution, making possible we propose a classification of these features, within a regional framework of Formação Barreiras: 1) cliffs preceded by a beach; 2) cliffs not preceded by a beach.
2

Falésias na Formação Barreiras: análise regional e proposta tipológica / Cliffs in Formação Barreiras: regional analysis and typological proposal

Adriana Aparecida Furlan 22 September 2014 (has links)
As formas naturais do relevo costeiro são resultantes da atuação e interação de processos continentais, oceânicos e atmosféricos. Dentre as diversas feições costeiras destacam-se as falésias e, nesta tese, serão discutidas estas feições esculpidas na Formação Barreiras, sendo esta uma vasta área sedimentar que se estende desde o estado do Rio de Janeiro até o estado do Amapá. Há um grande conjunto de elementos em interação atuando na morfogênese e evolução das falésias e estes são considerados dentro de uma perspectiva de análise sistêmica, sendo estes agrupados e caracterizados como elementos de um Sistema Natural, considerando-se o sistema como um conjunto formado por materiais, processos e formas, tratados, nesta tese, como um sistema geomórfico dinâmico com entrada (inputs) e saída (outputs) de energia e materiais identificáveis, dirigidos e controlados pelas condições ambientais, no qual inúmeros tipos de processos ocorrem simultaneamente. Estudos teóricos e de campo foram realizados em Beberibe-CE, Mucuri-BA e Tibau do Sul-RN e possibilitaram a observação e identificação de características e indícios da morfogênese e evolução das falésias, permitindo a proposição de uma classificação, dentro de um quadro regional da Formação Barreiras, destas feições em: 1) falésia precedida por praia; 2) falésia não precedida por praia. / Natural forms of coastal relief are the result of the action and interaction of continental, oceanic and atmospheric processes. Among various coastal features, cliffs stand out and in this thesis, we discuss these features carved into Formação Barreiras, which is a vast sedimentary area stretching from Rio de Janeiro to Amapá State. There is a large set of elements in interaction taking part in the morphogenesis and in the evolution of cliffs which are considered here within the perspective of a systemic analysis. These elements are classified and characterized as elements of a \"Natural System\", considered system as a whole formed by materials, processes and forms, treated, in this thesis, as a dynamic geomorphic system with inputs and outputs of strenght and materials identifiable, directed and controlled by environmental conditions, in which numberless types of material processes occur simultaneously. Theoretical and field studies performed in Beberibe-CE, Mucuri-BA and Tibau do Sul-RN, allowed us to observe and identify characteristics and evidences of cliffs morphogenesis and evolution, making possible we propose a classification of these features, within a regional framework of Formação Barreiras: 1) cliffs preceded by a beach; 2) cliffs not preceded by a beach.
3

Coupled Modeling of Economic – Hydrological Systems: Examining Spatial Heterogeneity in Water Quality Benefits and Optimal Agricultural Land Use Management in Ohio

Liu, Hongxing 13 October 2017 (has links)
No description available.
4

Wildfire as Coupled Human Natural System

Farkhondehmaal, Farshad 01 February 2022 (has links)
Wildfire activity has increased in recent years in the United States, endangering both environment and society. Appropriate management of this phenomenon is only achievable with a thorough understanding of the critical factors influencing wildfire activity in each region. In three essays, I use statistical and mathematical models to examine wildfires and propose solutions to mitigate their impact on society. In the first essay, I focused on building a systematic framework for modeling wildfire as a coupled human-natural system. I employ system dynamics modeling, which was previously applied in various fields, including healthcare, sustainability, and disaster mitigation. I show how, in the absence of exogenous factors such as temperature or lightning, the human perception of fire danger may establish a feedback loop that can yield significant trends such as fluctuation or even fluctuation with rising amplitude when linked with the natural system. This conclusion is counter-intuitive, given that the human contribution to wildfire is typically described in the literature using constant or semi-constant variables. Additionally, I analyzed the impact of three important fire protection measures on reducing burning rates (prescribed burning, enhancing immediate suppression accomplishment, and regulating the rate of WUI growth). The research concludes that appropriately integrating several policies can result in a synergistic effect that is greater than the sum of the effects of the individual policies. The second essay calibrates the model built in the first essay and examines wildfire trends across the contiguous United States. The simulation results closely match the real data, and the model serves as a foundation for data-driven policy research. To be more precise, I fit the model to each state separately and then compare the model's goodness of fit. Following that, I examine the influence of various policies and scenarios on wildfire behavior. In the scenario, I examine the effect of maintaining constant temperatures and precipitation levels relative to the average values for these variables over the last century. For the policy analysis, I examine the influence of three policies on each state (prescribed burning, increasing immediate suppression achievement, and regulating the rate of WUI development). Here, I provide state-specific suggestions about the primary factors that contribute to wildfires and the most effective policies for each state. In the third essay, I have implemented the Oregon wildfire history dataset and integrated it with two other aerial datasets, including meteorological data gathered by weather stations located around the state and counties. Then, using hierarchical modeling on over 10,000 wildfire ignitions, I developed a classification system for determining if a given fire has the potential to grow major or not. However, utilizing a huge dataset and a variety of resources presents several obstacles, such as the presence of missing data. I imputed the missing numbers using a sophisticated mathematical approach called "Predictive Mean Matching". / Doctor of Philosophy / Wildfire activity has increased in recent decades in the United States, which put many people in danger. Climate change, the Settlement of people in the Wildland Urban Interface, and an increase in vegetation density each play a role in this increase. In this dissertation, we discuss the wildfire in the United States in three essays. In the first essay, we develop a mathematical model to show how humans and nature affect wildfire activity in any area. We then test different major wildfire management policies on the hypothetical situation to compare the outcome of these policies together. In the second essay, we use the model developed in the essay (with some minor changes) to model the wildfire activity in 11 states of the U.S. which has the most wildfire activity in recent years. First, we show that our model can replicate the wildfire activity in each state. Second, we test the effect of wildfire mitigation policies on each state. This essay proposes state-specific policy recommendations based on the main reasons for the increase in wildfire activity in each state. Finally, in the third essay, we develop a statistical model to predict the existence of large wildfires in the next month in Oregon counties. We use climate, land, and fire history data to develop a warning system. Policymakers can use this system to move the fire suppression resources to counties with a high probability of experiencing large wildfires over the next month. Finally, all essays aim to enhance our understanding of the reasons for the increase in wildfire activity in recent years and suggest finding the appropriate way to deal with this change to reduce the effect of wildfire on human life.
5

Disgnóstico ambiental do setor noroeste do sítio urbano de Piracicaba (SP) : uma abordagem geográfica /

Silveira, Alan. January 2009 (has links)
Orientador: Cenira Maria Lupinacci da Cunha / Banca: Jurandyr Luciano Sanches Ross / Banca: Pompeu Figueiredo de Carvalho / Resumo: Esta pesquisa tem como objetivo fornecer um diagnóstico ambiental detalhado, de abordagem geográfica integrada, que venha a subsidiar ações de planejamento territorial do eixo de expansão urbana noroeste do sítio urbano de Piracicaba (SP). Fundamentada na Teoria Geral dos Sistemas, aplicou-se para a área de estudo a proposição metodológica de Ross (1990, 1994 e 2001), quanto à análise empírica da fragilidade de ambientes naturais e antropizados, assim como a proposta metodológica de Moroz, Canil e Ross (1994), na análise das condições de impactos ambientais derivados do uso e ocupação antrópica e das transgressões à legislação ambiental. Tais proposições metodológicas promoveram a elaboração de produtos cartográficos de síntese para análise integrada da informação geográfica, por meio da elaboração prévia de documentos cartográficos intermediários. Com base nos documentos cartográficos formulados, pretendeu-se apontar as condições impactantes impostas as formas de relevo, suas suscetibilidades aos processos morfodinâmicos, as transgressões relativas à legislação ambiental, como também apontar as áreas com restrições à expansão do sítio urbano do setor noroeste de Piracicaba, tanto do ponto de vista da fragilidade potencial, quanto do ponto de vista legal. Pôde-se constatar que as ações promovidas pelo sistema antrópico vêm alterando os fluxos de matéria e energia do sistema geomorfológico, sendo as principais formas de interferências associadas à monocultura canavieira e à expansão urbana sem planejamento. / Abstract: This research aims to supply a detailed environmental diagnosis, considering an integrated geographical approach, which subsidizes territorial planning actions in the northwest urban expansion axis of Piracicaba (SP) urbane siege. It was based on the General System Theory and, for the studied area, it was applied a Ross' methodological proposition (1990, 1994 e 2001), concerning the empirical analysis of natural and anthropized environmental fragility, as well as the Moroz, Canil and Ross‟ methodological proposal (1994) for the analysis of the conditions of environmental impacts derived from the anthropical use and occupation and the transgressions to the environmental legislation. These methodological propositions furthered the elaboration of synthesis cartographic products for the geographical information integrated analysis by the previous elaboration of intermediate cartographic documents. We intended to point, from the formulated cartographic documents, the impressive conditions imposed to the relief, its susceptibilities to the morphodynamic processes, the transgressions related to the environmental legislation, as well as the areas with restrictions to expansion of the Piracicaba (SP) northwestern sector urbane siege, as the potential fragility point of view, as the legal one. We could verify that the actions promoted by the anthropical system are modifying the matter and energy flows of the geomorphological system and that the main interference forms are associated to sugar cane monoculture and the no-planning urban expansion. / Mestre
6

Βελτιστοποίηση φυσικών συστημάτων επεξεργασίας υγρών αποβλήτων

Γαλανόπουλος, Χρήστος 05 February 2015 (has links)
Η μελέτη ενός πειράματος μικρής πιλοτικής κλίμακας, με δύο παράλληλα συστήματα ρηχών λεκανών (ύψους 0.35m), η μία λεκάνη με φύτευση του είδους Typha Latifolia και η άλλη χωρίς φύτευση, διεξάχθηκε για τον σχεδιασμό ελεύθερης επιφανειακής ροής (FWS) τεχνητού υγροτόπου. Οι δύο λεκάνες τροφοδοτήθηκαν με πραγματικά αστικά λύματα όπου οι χρόνοι παραμονής κυμάνθηκαν από 27,6 έως 38,0 ημέρες. Η μεταβολή του όγκου κάθε λεκάνης παρακολουθήθηκε για 2 συνεχή έτη και ταυτόχρονα υπολογίστηκαν οι ρυθμοί βροχόπτωσης και εξάτμισης. Η διαφορά του όγκου μεταξύ των δύο λεκανών οφειλόταν στην πρόσληψη νερού από τα φυτά, η οποία συγκρίθηκε με τις προβλέψεις της εξατμισοδιαπνοής παρόμοιων φυτών με την χρήση του υπολογιστικού προγράμματος REF-ET. Η συγκομιδή των φυτών πραγματοποιήθηκε τρείς φορές στην διάρκεια του 1ου έτους του πειράματος, ώστε να εκτιμηθεί ο ρυθμός πρόσληψης αζώτου από τα φυτά. Η σημαντικότερη διαφορά των δύο συστημάτων ήταν η αφαίρεση νερού μέσω της εξατμισοδιαπνοής των φυτών. Η πιλοτική μονάδα λειτούργησε έτσι ώστε να επιτευχθεί και απομάκρυνση της οργανικής ύλης (BOD5) και του ολικού αζώτου (TN) από τα λύματα. Ο σχεδιασμός της διευκόλυνε την ανάπτυξη ενός μαθηματικού μοντέλου, ακολουθώντας το πλαίσιο του μοντέλου της ενεργής ιλύος (ASM). Αρχικά το μαθηματικό μοντέλο αναπτύχθηκε για τις δύο λεκάνες με τις μικροβιακές διεργασίες που επικράτησαν στο εσωτερικό τους, ώστε να περιγραφεί πλήρως η συμπεριφορά τους. Η προσομοίωση και η εκτίμηση των παραμέτρων του μοντέλου επιτεύχθηκε με την χρήση του υπολογιστικού περιβάλλοντος του AQUASIM. Οι κύριες διεργασίες που ελήφθησαν υπόψη για την μοντελοποίηση ήταν η αμμωνιοποίηση, η αερόβια ετεροτροφική ανάπτυξη, η νιτροποίηση και η ανάπτυξη φυκών. Μια ισχυρή εποχική εξάρτηση παρατηρήθηκε για την συμπεριφορά κάθε λεκάνης όταν το μοντέλο εφαρμόστηκε για το 1ο έτος του πειράματος. Αυτό το μοντέλο επαληθεύτηκε ικανοποιητικά με τα πειραματικά δεδομένα του 2ου έτους. Η παρατηρούμενη μέση ετήσια απόδοση απομάκρυνσης του BOD5 και του TN ήταν 60% και 69%, αντίστοιχα για την λεκάνη χωρίς φυτά και 83% και 75%, αντίστοιχα για την λεκάνη με φυτά. Το μοντέλο προέβλεψε μέση ετήσια απόδοση απομάκρυνσης 82% για το BOD5 και 65% για το TN στην λεκάνη με φυτά, ικανοποιώντας τα κριτήρια για τον σχεδιασμό πλήρους κλίμακας τεχνητού υγροτόπου . Η ικανότητα του μοντέλου να προβλέπει όχι μόνο την απομάκρυνση της οργανικής ύλης αλλά και του ολικού αζώτου, θεωρήθηκε επαρκής όταν δοκιμάστηκε με έναν ελεύθερης επιφανειακής ροής τεχνητό υγρότοπο με 400 ισοδύναμο πληθυσμό, με μοναδική τροποποίηση τον συνυπολογισμό του περιορισμού του οξυγόνου στον ρυθμό της διεργασίας της νιτροποίησης. Επομένως, το δυναμικό μοντέλο διαμορφώθηκε με την ενσωμάτωση της πρόβλεψης του ρυθμού της εξατμισοδιαπνοής των φυτών και χρησιμοποιήθηκε για τον σχεδιασμό περίπτωσης μελέτης τεχνητού υγροτόπου πλήρους κλίμακας. Τα στοιχεία που απαιτούνται για αυτό τον σχεδιασμό περιλάμβαναν την παροχή εισόδου και κλιματολογικά στοιχεία (θερμοκρασίας και βροχόπτωσης) για την περιοχή του σχεδιασμού, καθώς και οι απαιτήσεις της ποιότητας εκροής. Η περίπτωση μελέτης για 4000 ισοδύναμο πληθυσμό όπου η ποιότητα εκροής ήταν σε μέσες ετήσιες τιμές BOD5=25mg/L και TN=15mg/L, χρειάστηκε μία συνολική επιφάνεια υγροτόπου 11 εκταρίων. Εάν χρησιμοποιηθούν δύο λεκάνες σε σειρά, η 1η με φυτά και η 2η χωρίς, τότε η συνολική επιφάνεια μειώνεται κατά περίπου 27%, ελέγχοντας μόνο την αρχική μέγιστη φύτευση της πρώτης λεκάνης του υγροτόπου. / The study at pilot-scale of two parallel systems with shallow basins (height h=0.35m), one planted with Typha Latiofolia and the other without vegetation, was conducted for the modeling of free water surface (FWS) constructed wetland systems. The basins were fed with real sewage at retention times ranging from 27.6 to 38.0 days. The variation of the volume in each basin was monitored for two consecutive years and simultaneously, rainfall and evaporation rates were calculated. The difference of the volume between the basins was due to the water absorption by the plants and was compared with the predictions of evapotranspiration rates of similar plants using the REF-ET calculation software. The harvesting of the plants was performed three times during the first year, in order to estimate the nitrogen uptake by the plants. The main difference in the two systems was the water removal through plant evapotranspiration. The pilot unit was operated so as to achieve the removal of both organic matter (BOD5) and total nitrogen (TN) from the sewage. Its design enabled the development of a mathematical model, following the framework of the activated sludge model (ASM). The simulation and the parameter estimation were achieved using the AQUASIM framework. The mathematical model describes the microbial processes, which dominated within the basins describing satisfactorily their behavior. The key processes accounted for in the modeling were ammonification, aerobic heterotrophic growth, nitrification and algal growth. A strong seasonal dependence was observed for each basin. The model was satisfactorily validated with the data of the second year. An observed average annual removal efficiency of BOD5 and TN were 60% and 69%, respectively for the basin without plants and 83% and 75%, respectively for the basin with plants. The model predicted average annual removal efficiency 82% for BOD5 and 65% for TN in the basin with plants, satisfying the design criteria of a full-scale constructed wetland. The ability of the model to predict not only the removal of organic matter but also total nitrogen removal, was considered sufficient as tested with a real free water surface constructed wetland of 400 population equivalent, with the sole modification being the inclusion of oxygen limitation in the nitrification rate. The dynamic model was amended with the direct incorporation of the plant evapotranspiration rate and it was used to design a full-scale constructed wetland. The required elements for this design included the inflow rate and climatic data (temperature and rainfall) for the design region, as well as the effluent quality requirements. In the case study of 4000 population equivalent, the effluent quality requirement was: average annual values for BOD5=25mg/L and for TN=15mg/L. The model was used to determine a total wetland surface requirement of 11ha. If two sequential basins are used, the first with plants and the second without, then the total wetland surface could be reduced by approximately 27%, controlling only the maximum initial vegetation in the first wetland basin.
7

Disgnóstico ambiental do setor noroeste do sítio urbano de Piracicaba (SP): uma abordagem geográfica

Silveira, Alan [UNESP] 01 October 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-10-01Bitstream added on 2014-06-13T20:36:19Z : No. of bitstreams: 1 silveira_a_me_rcla.pdf: 2707026 bytes, checksum: 73ca0833e135ac48c8f366d2302015cf (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Esta pesquisa tem como objetivo fornecer um diagnóstico ambiental detalhado, de abordagem geográfica integrada, que venha a subsidiar ações de planejamento territorial do eixo de expansão urbana noroeste do sítio urbano de Piracicaba (SP). Fundamentada na Teoria Geral dos Sistemas, aplicou-se para a área de estudo a proposição metodológica de Ross (1990, 1994 e 2001), quanto à análise empírica da fragilidade de ambientes naturais e antropizados, assim como a proposta metodológica de Moroz, Canil e Ross (1994), na análise das condições de impactos ambientais derivados do uso e ocupação antrópica e das transgressões à legislação ambiental. Tais proposições metodológicas promoveram a elaboração de produtos cartográficos de síntese para análise integrada da informação geográfica, por meio da elaboração prévia de documentos cartográficos intermediários. Com base nos documentos cartográficos formulados, pretendeu-se apontar as condições impactantes impostas as formas de relevo, suas suscetibilidades aos processos morfodinâmicos, as transgressões relativas à legislação ambiental, como também apontar as áreas com restrições à expansão do sítio urbano do setor noroeste de Piracicaba, tanto do ponto de vista da fragilidade potencial, quanto do ponto de vista legal. Pôde-se constatar que as ações promovidas pelo sistema antrópico vêm alterando os fluxos de matéria e energia do sistema geomorfológico, sendo as principais formas de interferências associadas à monocultura canavieira e à expansão urbana sem planejamento. / This research aims to supply a detailed environmental diagnosis, considering an integrated geographical approach, which subsidizes territorial planning actions in the northwest urban expansion axis of Piracicaba (SP) urbane siege. It was based on the General System Theory and, for the studied area, it was applied a Ross' methodological proposition (1990, 1994 e 2001), concerning the empirical analysis of natural and anthropized environmental fragility, as well as the Moroz, Canil and Ross‟ methodological proposal (1994) for the analysis of the conditions of environmental impacts derived from the anthropical use and occupation and the transgressions to the environmental legislation. These methodological propositions furthered the elaboration of synthesis cartographic products for the geographical information integrated analysis by the previous elaboration of intermediate cartographic documents. We intended to point, from the formulated cartographic documents, the impressive conditions imposed to the relief, its susceptibilities to the morphodynamic processes, the transgressions related to the environmental legislation, as well as the areas with restrictions to expansion of the Piracicaba (SP) northwestern sector urbane siege, as the potential fragility point of view, as the legal one. We could verify that the actions promoted by the anthropical system are modifying the matter and energy flows of the geomorphological system and that the main interference forms are associated to sugar cane monoculture and the no-planning urban expansion.

Page generated in 0.06 seconds