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  • 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.
861

A Cota de Reserva Ambiental no Novo Código Florestal Brasileiro: propostas para a efetividade / Environmental Reserve Quota on the New Brazilian Forest Code: proposals to effectiveness

Luis Eduardo Brito Scoton 09 March 2017 (has links)
O presente trabalho discute o conceito e natureza jurídica da Cota de Reserva Ambiental (CRA) enquanto instrumento de política ambiental previsto no Novo Código Florestal Brasileiro (Lei Federal nº 12.651/12). O problema de pesquisa se funda em saber se a atual proposta de regulamentação da CRA permitirá a efetividade do instituto. Aspectos teóricos foram discutidos com base em material documental e bibliográfico, recolhidos no âmbito das ciências do direito e da economia. Ao fim, foi realizada pesquisa exploratória sobre o tema, baseada em entrevistas com gestores ambientais, analisadas sob o método dialético-qualitativo. O objetivo, de modo geral, é discutir o atual marco regulatório sobre o tema, de modo criar propostas a sua efetividade. / This paper discusses the concept and legal nature of the Environmental Reserve Quota (CRA) as an environmental policy instrument regulated by the New Brazilian Forest Code (Federal Law nº 12.651/12). The research problem seeks to identify if the current proposal for regulation of the CRA will allow the effectiveness of this institute. Theoretical aspects were discussed on the basis of documentary and bibliographic material collected in the sciences of law and economics. By the end, an exploratory research was conducted on the subject, based on interviews with environmental managers, analyzed from a dialectical qualitative method. The goal, in general, is to discuss the current regulatory framework on the subject with the intention to make proposals to its effectiveness.
862

Raposa Serra do Sol = agentes políticos, conflitos e interesses / Raposa Serra do Sol : political agents, conflicts and interests

Silva, Marcelle Ivie da Costa, 1980- 19 August 2018 (has links)
Orientador: Shiguenoli Miyamoto / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciências Humanas / Made available in DSpace on 2018-08-19T21:04:38Z (GMT). No. of bitstreams: 1 Silva_MarcelleIviedaCosta_D.pdf: 8330753 bytes, checksum: f696b09aa3617335ba6d4a8e9c501e15 (MD5) Previous issue date: 2012 / Resumo: A proposta deste trabalho é realizar um mapeamento dos múltiplos agentes políticos envolvidos em torno da demarcação da Terra Indígena Raposa Serra do Sol, contemplando suas respectivas argumentações, e analisar os conflitos políticos engendrados pela questão. Ao estudar esse processo demarcatório que durou três décadas, buscamos relacionar satisfatoriamente os aspectos políticos internos que culminaram na demarcação contínua da TIRSS com processos políticos mais amplos, ou seja, compreender a questão a partir de três níveis de análise: o local (estado de Roraima), o nacional (República Federativa do Brasil) e internacional (mundo) / Abstract: The aim of this work is to map the multiple political actors involved in the demarcation of the Indian region named Raposa Serra do Sol (TIRSS), contemplating each actor's arguments, and to analyze the political conflicts generated by this issue. By studying this demarcation process that lasted three decades, we tried to successfully relate the domestic political aspects, that resulted in the continuous demarcation of TIRSS, with wider political processes. Thus, this research approaches the understanding of the issue from three levels of analysis: local (state of Roraima), national (Federative Republic of Brazil) and international (world) / Doutorado / Ciencia Politica / Doutor em Ciência Política
863

Testing the existence and direction of "spill-over" of mussel recruits beyond the boundaries of marine protected areas

Ludford, Adam January 2011 (has links)
Landscape ecology helps in predicting the influence of habitat fragmentation on populations. Marine protected areas (MPAs) are expected to create areas of good quality patches and so improve connectivity among shores. MPAs are believed not only to protect adult populations, but also to enhance recruitment both within MPAs and on surrounding exploited shores, therefore improving their ability to recover from overexploitation. As such, MPAs are a preferred management tool for the conservation of natural populations. Although MPAs have been demonstrated to enhance adult abundances, little work has been done on their ability to provide so called "spill-over" of recruits nor has the generality of the influence of MPAs been investigated in a single region with multiple control sites. The Transkei region, on the east coast of South Africa, and the intertidal mussel, Perna perna, offer an ideal system to test the generality of the influence of MPAs on surrounding shores, due to the presence of multiple MPAs and exploited control sites. Patterns of adult abundance were surveyed at four MPAs and two comparably sized exploited control sites. Adult abundances were, in general, found to be higher within MPAs than at exploited control sites, with adult abundances decreasing towards the edge of MPAs and decreasing even more on the outside shores. To simplify the sorting procedure for samples of mussel recruits, a new method using fractionated elutriation was devised and tested. This new method was found to be more accurate, although not statistically significant but also substantially more time consuming. The increase in accuracy although not statistically significant could be biologically significant, especially when looking at low numbers. This new method could, therefore, be very useful especially when [...] is low. Recruitment was estimated over three months during the main reproductive season at two of the MPAs and at appropriate control sites. I predicted that recruitment patterns would mirror the patterns found in adult abundances and that there would be directionality in patterns of recruitment, with northern sites having greater recruitment due to the direction of near-shore ocean currents. Contrary to this, there were no correlations between adult abundance and recruitment for any of the months or sites, with no clear spatial pattern of recruitment in any of the three months. There was, however, a slight trend of greater recruitment at northern sites. To explain the lack of consistency in recruitment and adult abundances, wind data were used to examine the near-shore surface currents in this area, with theoretical surface currents showing similar patterns to those observed for recruitment. From a landscape perspective, the good patches created by MPAs supply recruits to the surrounding matrix but the low quality of habitat in the matrix prevents rehabilitation. The quality of the matrix must therefore be first improved by reseeding these shores. These results emphasise that while MPAs may function in protecting adult abundances, their influence on supplying recruits and hence recovery of near-by exploited shores may be overestimated. This lack of influence on near-by exploited shores highlights the need for reseeding of shores in conjunction with suitable management plans.
864

Towards a cost-efficient & standardised monitoring protocol for subtidal reef fish in the Agulhas ecoregion of South Africa / Towards a cost-efficient & standardised monitoring protocol for sub-tidal reef fish in the Agulhas eco-region of South Africa

Bernard, Anthony Thomas Firth January 2013 (has links)
Under the growing demand for marine fish resources, and the apparent and expected impacts of global climate change, there is a need to conduct long-term monitoring (LTM) to ensure effective management of resources and conservation of biodiversity. However LTM programmes often suffer from design deficiencies and fail to achieve their objectives. These deficiencies stem from the fact that insufficient consideration is afforded to the design phase, with programmes selecting methods that are not suitable to address the objectives, or are not cost-efficient, compromising the sustainability of the LTM. To facilitate the establishment of LTM programmes along the southern coast of South Africa, background research needed to be conducted to identify which methods were most appropriate for LTM of reef fish. This study presents a detailed field-based assessment of the suitability and cost-efficiency of monitoring methods for long-term monitoring of reef fish in the Agulhas Ecoregion of South Africa. The approach adopted to identify the method, or suite of methods most suited for LTM, involved (i) the selection of methods considered suitable for LTM, (ii) the individual assessment and optimisation of method performance, and (iii) the comparative assessment of the fish community sampled by the different methods. The most suited method(s) were then identified as those that provide the most comprehensive assessment of the fish community and had the highest cost-efficiency. The research was conducted between January 2008 and 2011 in the Tsitsikamma and Table Mountain National Park (TNP and TMNP, respectively) marine protected areas (MPAs) within the Agulhas Ecoregion. The methods selected included fish traps (FT), controlled angling (CA), underwater visual census (UVC), remote underwater video (RUV), baited RUV (BRUV) and remotely operated vehicles (ROV). The individual assessment and optimisation was conducted with the FT, UVC, RUV and BRUV methods. The assessment of the FT method aimed to identify the optimal soak time, and whether or not the size of the funnel entrance to the trap affected the catch. The results identified that larger funnel entrances caught more fish and soak times of 80 minutes produced the highest catches per unit effort. However the data were highly variable and the method detected few of the species typical of the region. Fish traps were also associated with high levels of mortality of fish post-release. The assessment of UVC strip transect method involved directly comparing the precision of data collected by researchers and volunteers using a novel double-observer technique (paired-transects). The results showed considerable error in both the volunteers and researchers data, however the researchers produced significantly higher precision data, compared to the volunteers. The distinction between researchers and volunteers was not evident in the data for the dominant species of fish. For all observers, the abundance of a species in the sample had a significant influence on its detectability, with locally scarce or rare species poorly detected. UVC was able to sample the majority of species typical of reefs in the region, however it appeared plagued by observer and detectability biases. The assessments of RUV and BRUV were conducted simultaneously which enabled the assessment of the effect of bait on the observed fish community. In addition the optimal deployment time for both methods to maximise species richness and abundance was determined. The results showed that BRUV, and to a lesser degree RUV, were able to effectively survey the reef fish community for the region with a 50 minute and 35 minute deployment time, respectively. Baited remote underwater video was especially good at detecting the invertebrate and generalist carnivores, and cartilaginous species. On the other hand, RUV was more effective at surveying the microinvertebrate carnivores. Remote underwater video was characterised by higher data variability, compared to BRUV, and was ultimately considered a less cost-efficient monitoring method. Comparative methods assessments were conducted during two field experiments with the FT, UVC and BRUV methods in the TMNP MPA, and the FT, CA, UVC, RUV, BRUV and ROV methods compared in the TNP MPA. The objectives of the comparison were to investigate differences in the fish communities observed with the different methods, and to determine the power of the data to detect an annual 10% growth in the fish populations over a period of five years. The results from the method comparison were in turn used to conduct the cost-benefit analysis to determine the efficiency of the different methods at achieving monitoring objectives requiring population data from multiple trophic and functional groups with the community, and from species of fisheries importance. The results indicated that FT, CA and ROV were ineffective at monitoring the reef fish community, although CA appeared to provide valuable data for the dominant fisheries species. Both CA and FT required minimal initial investment however, the variability in the data translated into high annual monitoring costs, as the required sampling effort was great. The ROV required the highest initial investment and was identified as the least cost-efficient method. Underwater visual census was able to adequately survey the bony fish within the community, however it did not detect the cartilaginous species. Underwater visual census required a large initial investment and was not cost-efficient, as a many samples were required to account for the variability in the data. Remote underwater video provided a comprehensive assessment of the reef fish community, however it too was associated with high levels of variability in the data, compared to BRUV, reducing its cost-efficiency. BRUV provided the most comprehensive assessment of the reef fish community and was associated with the highest cost-efficiency to address the community and fisheries species monitoring objectives. During the course of this research stereo-BRUV has gained considerable support as an effective reef fish monitoring method. Although not tested during this research, stereo-BRUV is preferred to BRUV as it provides accurate data on the size of fish. However, the initial investment of stereo-BRUV is over three times that required for the BRUV. Although it is recommended that a baited video technique be used for LTM in the Agulhas Ecoregion, the choice between BRUV and stereo-BRUV will depend on the specific objectives of the programme and the available budget at the implementing agency.
865

Assessment of the effect of Goukamma Marine Protected Area on community structure and fishery dynamics

Götz, Albrecht January 2006 (has links)
This study presents a detailed investigation into size, density and community structure of temperate marine reef fish in the medium-sized Goukamma Marine Protected Area (Goukamma MPA) and adjacent fishing grounds on the south coast of South Africa. The oceanographic conditions, the spatial distribution of the benthic community and the prevailing fishing effort are also described. Life history traits and per-recruit (PR) models for the principle target species, roman (Crysoblephus laticeps) are compared between the protected and exploited area. From the study results, various strategies are proposed for the use of MPAs in the conservation and management of linefish species along South Africa’s south coast. The distribution and topography of reefs in the protected and exploited sections of the study area were found to be comparable. Atmospheric pressure ranged from 992 to 1,032 mb, being significantly lower in summer. Wind speeds ranged from 0.7 to 71.3 km/h. Water temperatures ranged between 9.0 and 22.2 ºC and turbidity between 0.3 and 45.8 NTU. Water temperature and clarity were uniformly low in winter. In summer the water was generally warm, clear and stratified, with a thermocline at around 20 m, although intermittent upwelling events caused water temperature to decrease and clarity to deteriorate. Current speeds ranged between 0.11 and 2.59 km/h and were significantly higher in spring and autumn. Easterly currents prevailed in spring, summer and autumn and westerly and southerly currents in winter. Hake (Merluccius capensis), various resident reef fish and kob (Argyrosomus japonicus) were most frequently targeted by the local linefishery. A significant amount of illegal fishing was found to occur in the protected area. Fishing effort was found to be highest around the border of the MPA (2.7 boats/km²) and lowest in the core of the MPA (0.2 boats/km²). If law enforcement remains poor it may be necessary to adapt the management strategy to extend the reserve, thereby mitigating against illegal fishing and ensuring a core area of no exploitation. Various other alternatives were investigated and it was demonstrated that the amount of fish caught of legal size could be increased by about 23% and post-release mortality of undersized fish reduced by 50% through the introduction of a suit of restrictive measures. Randomly stratified underwater visual census (UVC) and controlled fishing were used to investigate the ichthyofauna and benthic community at protected and exploited sites in the study area. Resulting density and size data from 273 fishing sites and 177 point counts were analyzed using generalized linear models (GLMs). Fish communities were found to vary significantly, depending on the level of exploitation. Roman, the principle reef fish species targeted by the fishery had significantly higher densities within the protected parts of the study area (CPUE: 4.3 fish/anglerhour; UVC: 2.2 fish/point-count) as compared to the exploited part (CPUE: 3.4 fish/anglerhour; UVC: 1.8 fish/point-count), correlating strongly with the observed fishing effort. Also mean sizes were significantly higher in the protected area (299 mm from fishing survey and 233 mm from diving estimates) as compared to the exploited section (283 mm from fishing survey and 198 mm from diving estimates). Although other fish species also had significantly higher mean sizes at protected sites in most cases their densities were significantly lower. This suggests a top-down control of the fish community by the dominant predator (roman). The results of the UVC showed the diversity of the ichthyofauna to be significantly higher inside the protected area. Interestingly this did not apply to the results of the controlled fishing experiment where the diversity of fish in the catch was lower in the protected area - a result that may be explained by the selectivity of fishing for the most aggressive species – and a reminder of the limitations of controlled fishing experiments. Possibly the most important finding of the study revolved around the benthic community. These were significantly different at exploited and protected sites, with algae and crinoids more abundant at exploited sites. Crinoids are the principle food of roman and were low in abundance where roman abundances were high, suggesting that the dominant top predator reduced crinoids. Furthermore, it substantiates the correlation of roman abundance with fishing effort, since habitat preferences can be ruled out by the observed causal predator-prey distribution pattern. Low algae abundances at protected sites correlated with high strepie (Sarpa salpa) frequencies within the fish communities encountered there. Strepie, a shoaling and abundant benthic grazer, does not compete for food with roman, suggesting a high potential for coexistence of the two species. As expected, and found by other studies, life history traits of roman differed between protected and exploited sample-sites. With a significantly lower age-at-maturity and age-atsex- change, the exploited population showed a typical response to fishing effort. The sex ratio of this protogynous hermaphrodite was found to be sustained at healthy levels by phenotypic plasticity. However, one important additional factor was highlighted by the study; the average condition factor of the protected population was significantly lower (0.0283 g/cm³) compared to the exploited population (0.0295 g/cm³). This was probably due to the higher intra-specific competition for lower food abundance in the protected area. Interestingly the diving and fishing survey methods yielded similar mortality results for roman. Total mortality rate estimates derived from length frequency analysis from the diving and fishing survey were not different (0.32 and 0.29 y⁻¹, respectively) as were natural mortality rate estimates (0.24 and 0.19 y⁻¹, respectively). Natural mortality rate (M) estimates indicated by Pauly’s and Hoenig’s relationship were similar (0.25 and 0.23 y⁻¹, respectively). Detailed yield-per-recruit (Y/R) and spawner biomass-per-recruit (SB/R) analyses were presented for different levels of M, varying age-at-recruitment (tR) and fishing mortality (F). Current tR (7.60 y) and F (0.16 and 0.25 y⁻¹, from the diving and fishing dataset, respectively) suggests an optimal exploitation of the population in the exploited part of the study area. However, a separate SB/R analysis of the male part of the population showed their vulnerability to over-exploitation, even at reduced age-at-sex-change from fishing. There therefore remains a high risk of recruitment failure for the roman population. Of course MPAs can be used to measure stock status directly if the influence of factors such as cachability, habitat and sampling method on CPUE assessments can be limited or reduced. The experimental design in this study allowed for contemporary CPUE comparisons across the border of the Goukamma MPA. Results were similar to those obtained by the SB/R analyses. CPUE extrapolations therefore, using small MPAs, can provide reliable and consistent estimates, and offer a practical alternative to conventional assessment strategies. This study has highlighted the importance of ensuring a well structured and comprehensive survey design when undertaking a comparison of protected and exploited marine areas. The results provide a comprehensive framework for future management of the Goukamma MPA and other protected areas along the temperate coastline of South Africa.
866

Larval fish dynamics in the shallow nearshore of Eastern Algoa Bay with particular emphasis on the effects of currents and swimming abilities on dispersal

Pattrick, Paula January 2008 (has links)
The larval fish assemblage in the shallow, nearshore region of a proposed marine protected area (MPA) in eastern Algoa Bay, temperate South Africa was investigated. Current velocities and direction and the swimming abilities of late-stage larvae were further assessed to determine potential larval movement to and from the MPA. In total, 6045 larval fishes were collected along two depth contours (~5m and ~15m) in the shallow nearshore of eastern Algoa Bay using stepped-oblique bongo net tows, twice per season for two years (March 2005 – January 2007). These larvae represented 32 families and 78 species. The Gobiidae, Cynoglossidae, Clupeidae, Engraulidae and Sparidae were the dominant fish families. Catches varied significantly between seasons peaking in spring with a mean of 64 larvae/100m3. Preflexion stage larvae dominated catches (75%). All developmental stages of Diplodus capensis, Engraulis capensis, Heteromycteris capensis, Sardinops sagax and Pomadasys species were found in the study area. It appears that these species use the shallow nearshore as a nursery area. Analysis of 12 months (May 2006 – May 2007) data from a bottom-moored Acoustic Doppler Current Profiler within the study area showed that offshore south eastward (39%) and onshore north westward currents (33%) dominated. The south westward current (15%) and north eastward current (12%) occurred less frequently. Current velocity decreased with depth in the nearshore, with a mean velocity of ~29 cms⁻¹ recorded at a depth of 4 m and a mean velocity of ~11 cms⁻¹ recorded at a depth of 14 m. Understanding the dispersal and movement of marine fish larvae in coastal habitats requires knowledge of active swimming abilities. The critical speed and endurance swimming of late stage larvae of two common inshore species occurring in the study area, Diplodus capensis and Sarpa salpa (Family Sparidae), were measured in a laboratory swimming chamber. The mean U-crit value for D. capensis (18.6 cms⁻¹) was similar to that of S. salpa (18.0 cms⁻¹), whereas mean endurance (km swum) was greater in S. salpa (8.4 km) than D. capensis (5.9 km). These swimming abilities exceed the average current velocities observed in the shallow nearshore providing larvae with the ability to greatly alter their passive dispersal trajectories and ultimately influence their distribution in the nearshore.
867

An analysis of the development model for ex-farmworkers and adjacent communities in the Indalo association of private game reserves in the Eastern Cape

Tessendorf, Samantha Millicent January 2015 (has links)
Over the past fifteen years there has been an extensive conversion of land use from traditional farming practices to conservation and private game reserves. It has been suggested by Langholz and Kerley (2006:2) that privately owned preserved areas can engage in ecotourism initiatives by protecting biodiversity, succeeding financially and contributing to social upliftment. However, ecotourism has to operate within the context of historical land dispossession of the majority black population and current land reform initiatives to address this problem. In view of the economic, social and environmental importance of ecotourism based private game reserves (PGRs) in South Africa, particularly the Eastern Cape, the main goal of this research is to examine the Indalo association of private game reserves in the Eastern Cape Province’s development model for ex-farmworkers and adjacent communities. This was done through a literature survey and analysis of existing studies and by interviewing the managers of the Indalo PGRs and a few farmworkers to get their opinions of the tension between what they are doing and the imperatives of land reform. This involved an exploration of their community development work, particularly around issues of job creation, participation in decision-making, capacity building and sustainability. The thesis comes to the following conclusions. The first is that the establishment of PGRs have a significant positive impact on the local areas in which they are established. As a land-use, ecotourism based game reserves are an economically and ecologically desirable alternative to other land uses. Therefore the ecotourism based private game reserve industry with its extensive community development focus for farmworkers and local communities is a viable and sustainable alternative to conventional land reform. The second is that the Indalo PGRs development work has built capacity in the communities it has served. However, community participation, particularly in decision-making is limited and needs more attention if productive and sustainable development is to be achieved. Lastly, communities rely heavily on external support for their development and upliftment. However, the majority of the PGRs have/or are putting measures in place to ensure the continuation of community development projects to ensure the long-term sustainability of projects.
868

Examining the feasibility of introducing environmental surcharges to finance local coastal management initiatives in South Africa : a case study in Plettenberg Bay

Mollatt, David G R January 2004 (has links)
The management of coastal resources in South Africa has come under review as a result of the degradation of environmental resources along the coast. The challenge being faced by resource managers is to achieve economic growth while sustaining South Africa’s coastal resource base (Nobel, 2000). The South African government (RSA, 2000) has developed a coastal management strategy to meet this challenge: The strategy involves the inclusion of all stakeholders in the formation of policy regarding the management of coastal resources, in a more integrated approach to coastal management. To effectively achieve this stakeholder inclusion, it has become necessary to decentralize the political, administrative and fiscal authority to conduct coastal management functions. With regard to the need for fiscal decentralisation this thesis considers the possibility of implementing localised environmental surcharges to finance coastal management initiatives. The ability of the White Paper for Sustainable Coastal Development (RSA, 2000) to provide theformal institutional structure necessary for the introduction of environmental surcharges is firstconsidered. It is shown that the decentralised management strategy has the potential to create a management style that is transparent and accountability orientated. In addition to this the style is capable of adapting to dynamic local coastal conditions and is therefore an appropriate direction in which to steer coastal management in South Africa. The effectiveness of coastal co-management as an informal institutional arrangement is then examined. Provided that local Coastal Management Fora are created to include all relevant stakeholders and that a source of long term financing is secured co-management has the potential to create the conditions necessary for effective coastal management. With regard to a source of long term financing, local environmental surcharges to finance coastal management initiatives are considered. The public’s willingness to contribute to such a surcharge is analysed in the context of Plettenberg Bay by probing their willingness to pay (WTP) for a Bay Management Plan. A survey instrument is developed to measure the public’s WTP. The design of the instrument is based on the Contingent Valuation (CV) method that is used to analyse the nonmarket benefits that environmental resources (such as Plettenberg Bay) provide the public. It is found that the resident population is willing to pay R15 per month toward a Bay Management Plan whilst domestic and foreign tourists respectively are willing to pay R6 and R22 daily. The aggregation of these WTP estimates yields a total passive use value of between R15 397 900 – R20330 500 annually. This nuclear value of the Bay should be included in the formation of local coastal management policy and provides guidance for the introduction of a local environmental surcharge. A budget for a Bay Management Plan is proposed and a progressive surcharge based on municipal property value is set. To finance the local residents’ share of the budget, a monthly surcharge of R1 would be required of the average valued property. To calculate the domestic and foreign tourist contribution to the budget a schedule of accommodation offering property will be required. However, to finance the entire budget a residential surcharge of approximately R10 would be required of the average valued property. This figure is well below the average resident population WTP of R15, highlighting the fact that an environmental surcharge in Plettenberg Bay is indeed feasible. The difference in reported WTP and the contribution required to finance the Bay Management Plan also highlights that there is scope for experimentation in the introduction of such a surcharge.
869

A mercantilização da paisagem natural nos Parques Nacionais do Sistema Nacional de Unidades de Conservação da Natureza

Santos, Mércia Carmelita Chagas Alves 14 March 2014 (has links)
This work, containing reflections on human-nature relationship, the perspective of the process of capitalist accumulation and in the light of geographical science and of Marxist theory , aims to analyze the relations between the state and capital , implied in the process that defines the commodification of landscape from the natural activity of ecotourism in the National Parks that are part of the National System of Conservation Units . It is noted therefore that the State, in view of the continuing need for capital expansion and responding to changes of modern times, proposed to be implemented in the National Parks and its environs, ecotourism as an economic activity capable of promoting " sustainable development . " However, this activity is the type of tourism in which nature itself is a commodity that should be consumed. The interference of the commodification of natural landscapes in the production of space these protected areas and their surroundings, with the territorial capital of the tourism demands geographers reflect the purpose of the particularities of results and contradictions of this process that transforms these spaces of accumulation territories of ecotourism, before the regime of flexible accumulation of the capital system, but also imposes question what defines it. And in this sense, it is necessary to note that the analysis of reality, without disregarding the changes observed with the rise of postmodern cultural forms, maintains the central argument is that the relationship between the state and capital that define this process. Besides the growth of visitation to National Parks, some observed in recent years related to public policy, such as a result of investments made in the Parks Program Guide , as well as related to private initiative , as investments made in some of these initiatives Conservations Units by companies that have the issue of support visitation services , supporting the continuum of this process . However, nothing guarantees that this will evolve in the future to the point of being mean to restructure the space of all the National Parks and its environs, which generally constitute the traditional territories of several and / or productive leisure activities, there view are the capitalists who, following the logic of capital, make the choices of the spaces in which they will realize their investments. The analysis highlights the fact that the actions of the State, for the development of ecotourism in protected areas that category were not followed in many of these by significant capital expenditures. But it should be noted that even before being perceived any significant interference with the territorial capital ecotourism in many National Parks, these conflicts of interests related to this process are observed, like the conflicts arising from the expropriation of areas with natural landscapes of great scenic beauty that must be turned into tourist attractions. Therefore, it is important to pay attention to the mystification around ecotourism, as well as the need to evaluate the results of this territorialization in the production of space based on social interest. And since the process being analyzed in this work, is ongoing, or even just begins, there is no pretense to launch definitive conclusions about the same, making it necessary to indicate its further analysis. / Este trabalho, contendo reflexões em torno da relação homem-natureza, na perspectiva do processo de acumulação capitalista e à luz da ciência geográfica e da teoria marxista, objetiva analisar as relações entre o Estado e o capital, subentendidas no processo que define a mercantilização da paisagem natural a partir da atividade do ecoturismo nos Parques Nacionais que integram o Sistema Nacional de Unidades de Conservação da Natureza. Nota-se, deste modo, que o Estado, atendendo à necessidade contínua de expansão do capital e respondendo às mudanças dos novos tempos, propõe que seja implementado nos Parques Nacionais e em seus entornos, o ecoturismo como uma atividade econômica capaz de promover o desenvolvimento sustentável . Entretanto, esta atividade é a modalidade de turismo na qual a natureza, em si, é a mercadoria que deve ser consumida. A interferência da mercantilização das paisagens naturais na produção do espaço dessas Unidades de Conservação e dos seus entornos, com a territorialização do capital turístico, exige dos geógrafos refletir a propósito das particularidades, dos desencadeamentos e das contradições desse processo que transforma esses espaços de acumulação em territórios do ecoturismo, diante do regime de acumulação flexível do sistema do capital, mas também impõe questionar o que o define. E, neste sentido, é mister observar que a análise da realidade, sem desconsiderar as mudanças observadas com a ascensão de formas culturais pós-modernas, sustenta o argumento central de que são as relações entre o Estado e o capital que definem esse processo. Além do crescimento da visitação aos Parques Nacionais, algumas iniciativas observadas nos últimos anos, relacionadas à política pública, a exemplo dos investimentos realizados em decorrência do Programa Turismo nos Parques, bem como relacionadas à iniciativa privada, como os investimentos efetuados em algumas dessas Unidades de Conservações por empresas que têm a concessão de serviços de apoio à visitação, sustentam a perspectiva de continuidade desse processo. Todavia, nada garante que este evolua a ponto de no futuro ser significativo para a reestruturação do espaço do conjunto dos Parques Nacionais e de seus entornos, os quais, de modo geral, constituem tradicionais territórios de atividades produtivas diversas e/ou de lazer, haja vista serem os capitalistas que, seguindo a lógica do capital, fazem as escolhas dos espaços em que irão realizar os seus investimentos. A análise da realidade evidencia que as ações do Estado, em prol do desenvolvimento do ecoturismo nas Unidades de Conservação dessa categoria, não foram seguidas em muitas destas por investimentos expressivos de capital. Mas deve-se observar que, mesmo antes de ser percebida qualquer interferência significativa da territorialização do capital com o ecoturismo em muitos Parques Nacionais, nestes, são observados conflitos de interesses relacionados a esse processo, a exemplo dos conflitos decorrentes das desapropriações de áreas com paisagens naturais de grande beleza cênica, que devem ser transformadas em atrativos turísticos. Assim sendo, é importante atentar para a mistificação em torno do ecoturismo, bem como para a necessidade de avaliar os resultados dessa territorialização na produção do espaço com base no interesse social. E, visto que o processo em análise neste trabalho encontra-se em curso, ou mesmo apenas se inicia, não se tem a pretensão de lançar conclusões definitivas sobre o mesmo, fazendo-se necessário indicar o prosseguimento da sua análise.
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Ein Beitrag zur Nutzbarmachung Genetischer Algorithmen für die optimale Steuerung und Planung eines flexiblen Stadtschnellbahnbetriebes

Albrecht, Thomas 04 May 2005 (has links)
The work deals with two problems of mass rapid transit system operation: The development of flexible timetables and the realisation of flexible timetables. In both cases, genetic algorithms are used. In the process of (flexible) timetabling in suburban railways, a transport offer perfectly adapted to demand is searched for (temporal and spatial adaptation of demand as well as adaptation of capacity of the trains). After determination of the number of train runs per line and hour and their capacity, optimal departure times have to be found (with a precision of a minute down to 10 s), which fulfil criterias of the passengers (short waiting times) as well as of the operator (small number of vehicles needed). Two different codings for use with genetic algorithms have therefore been developed. They are tested on several case studies of the Dresden suburban railway network, assuming different degrees of flexibilisation. In the process of realising a flexible timetable, transitions between train headways as well as running time and dwell time reserves (margins in the order of a few seconds) are slightly modified in order to coordinate braking and accelerating trains and thereby reduce energy costs of a system of trains. Genetic algorithms can be applied for this problem as well, the proposed methods are tested on several case studies (S-Bahn Berlin, Metro Lille). / Die Arbeit behandelt zwei Probleme der Betriebsplanung von Stadtschnellbahnen: Die Erstellung flexibler Fahrpläne und die Umsetzung flexibler Fahrpläne. In beiden Fällen werden zur Lösung Genetische Algorithmen verwendet. Bei der Ermittlung flexibler Fahrpläne von S-Bahnen wird ein bestmöglich an die Verkehrsnachfrage angepasstes Verkehrsangebot gesucht (zeitlich, räumlich und bezüglich der Kapazität der einzelnen Züge angepasst). Nach stundenfeiner Festlegung der Fahrtenhäufigkeiten und Kapazitäten der einzelnen, sich überlagernden Linien werden deren Abfahrtszeiten gesucht (mit einer Genauigkeit von Minuten bis etwa 10 s), so dass sowohl die Wünsche der Fahrgäste nach gleichmäßigen Zugfolgezeiten als auch Betreiberwünsche (geringe Fahrzeuganzahl) erfüllt werden. Hierzu werden zwei verschiedene Kodierungen für die Verwendung mit Genetischen Algorithmen vorgestellt und das geschaffene Verfahren an verschiedenen Flexibilisierungsszenarien für die S-Bahn Dresden erprobt. Bei der Umsetzung flexibler Fahrpläne, die sich im Bereich weniger Sekunden abspielt, werden Übergänge zwischen Zugfolgezeiten, Fahr- und Haltezeitreserven geringfügig modifiziert, so dass durch bestmögliche Koordination von Anfahr- und Bremsvorgängen eines Systems von Zügen die Energiekosten minimal werden. Methodisch werden wiederum Genetische Algorithmen verwendet, die Erprobung des Verfahrens erfolgt anhand von Linien der S-Bahn Berlin und der Metro in Lille.

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