58 resultados para URBAN CLIMATE


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In this paper we analyse some of the organisational aspects of the urban solid waste collection and, in particular, the privatization modality of contracting out. We start by discussing some of the theoretical aspects of contracting out. We then specify and estimate an explanatory model on a sample of municipalities that we surveyed. Our purpose is twofold: on the one hand, we identify the economic factors at work when deciding to contract out the service and, on the other hand, we analyse the role of ideological factors in choosing between the public production of the service or contracting it out. The results show a significant effect of the demand for waste collection on contracting out. There also appears to be a neighbouring effect as the municipalities close to other cities that contract out are also more prone to do so. Finally, the decisions to contract seem to have been motivated by pragmatic rather than ideological reasons.

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[spa] En lo que concierne al cambio climático, los pronósticos de cercanos picos de combustible fósiles parecen buenas noticias pues la mayoría de las emisiones proceden de la quema de combustibles fósiles. Sin embargo, esto podría resultar engañoso de confirmarse las enormes estimaciones de reservas de carbón pues puede divisarse un intercambio de combustible fósiles con baja concentración de carbono (petróleo y gas) por otros de mayor (carbón). Ciñéndonos a esta hipótesis desarrollamos escenarios donde tan pronto el petróleo y el gas natural alcanzan su cénit la extracción de carbón crece lo necesario para compensar el descenso de los primeros. Estimamos las emisiones que se deriva de tales supuestos y las comparamos con el peor escenario del IPCC. Si bien dicho escenario parece improbable concluimos que los picos de petróleo y gas no son suficientes para evitar peligrosas sendas de gases de efecto invernadero. Las concentraciones de CO2 halladas superan con creces las 450 ppm sin signos de remisión.

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This paper examines the most productive authors, institutions and countries in regional and urban science from 1991 to 2000 using information on published articles (and pages) from a sample of widely recognized journals in this field: ARS, JUE, JRS, IJURR, IRSR, PRS, RSUE, RS and US. We also consider the relation between the country of the institution named in articles and the country in which the journal is published, in order to know if there are a home publication bias in regional and urban science. Analysis was made for the whole decade and by subperiods, this allowed us to make a more dynamic interpretation of the results

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The current state of regional and urban science has been much discussed and a number of studies have speculated on possible future trends in the development of the discipline. However, there has been little empirical analysis of current publication patterns in regional and urban journals. This paper studies the kinds of topics, techniques and data used in articles published in nine top international journals during the 1990s with the aim of identifying current trends in this research field

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A small, closed, lacustrine system developed during the restraining overstep stages of the Oligocene As Pontes strike-slip basin (Spain). The increase in basin accommodation and the headward spread of the drainage, which increased the water input, triggered a change from shallow, holomictic to deeper, meromictic conditions.

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In this paper we analyse some of the organisational aspects of the urban solid waste collection and, in particular, the privatization modality of contracting out. We start by discussing some of the theoretical aspects of contracting out. We then specify and estimate an explanatory model on a sample of municipalities that we surveyed. Our purpose is twofold: on the one hand, we identify the economic factors at work when deciding to contract out the service and, on the other hand, we analyse the role of ideological factors in choosing between the public production of the service or contracting it out. The results show a significant effect of the demand for waste collection on contracting out. There also appears to be a neighbouring effect as the municipalities close to other cities that contract out are also more prone to do so. Finally, the decisions to contract seem to have been motivated by pragmatic rather than ideological reasons.

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[spa] En lo que concierne al cambio climático, los pronósticos de cercanos picos de combustible fósiles parecen buenas noticias pues la mayoría de las emisiones proceden de la quema de combustibles fósiles. Sin embargo, esto podría resultar engañoso de confirmarse las enormes estimaciones de reservas de carbón pues puede divisarse un intercambio de combustible fósiles con baja concentración de carbono (petróleo y gas) por otros de mayor (carbón). Ciñéndonos a esta hipótesis desarrollamos escenarios donde tan pronto el petróleo y el gas natural alcanzan su cénit la extracción de carbón crece lo necesario para compensar el descenso de los primeros. Estimamos las emisiones que se deriva de tales supuestos y las comparamos con el peor escenario del IPCC. Si bien dicho escenario parece improbable concluimos que los picos de petróleo y gas no son suficientes para evitar peligrosas sendas de gases de efecto invernadero. Las concentraciones de CO2 halladas superan con creces las 450 ppm sin signos de remisión.

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Abstract. Drought leads to a loss of longitudinal and lateral hydrologic connectivity, which causes direct or indirect changes in stream ecosystem properties. Changes in macrohabitat availability from a rifflepool sequence to isolated pools are among the most conspicuous consequences of connectivity loss. Macroinvertebrate assemblages were compared among 3 distinct stream macrohabitats (riffles [R], pools connected to riffles [Pc], disconnected pools [Pd]) of 19 Mediterranean-climate sites in northern California to examine the influence of loss of habitat resulting from drought disturbance. At the time of sampling, 10 sites were perennial and included R and Pc macrohabitats, whereas 9 sites were intermittent and included only Pd macrohabitats. Taxa richness was more variable in Pd, and taxa richness was significantly lower in Pd than in Pc but not R. These results suggested a decline in richness between Pc and Pd that might be associated with loss of connectivity. Lower Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness relative to Odonata, Coleoptera, and Heteroptera (OCH) richness was observed for Pd than R and Pc macrohabitats. Family composition was more similar between R and Pc than between R or Pc and Pd macrohabitats. This similarity may be associated with greater connectivity between R and Pc macrohabitats. Correspondence analysis indicated that macroinvertebrate composition changed along a gradient from R to Pc and Pd that was related to a perennialintermittent gradient across sites. High variability among macroinvertebrate assemblages in Pd could have been related to variability in the duration of intermittency. In cluster analysis, macroinvertebrate assemblages were grouped by macrohabitat first and then by site, suggesting that the macrohabitat filter had a greater influence on macroinvertebrate assemblages than did local site characteristics. Few taxa were found exclusively in Pc, and this macrohabitat shared numerous taxa with R and Pd, indicating that Pc may act as a bridge between R and Pd during drought. Drought is regarded as a ramp disturbance, but our results suggest that the response of macroinvertebrate assemblages to the loss of hydrological connectivity among macrohabitats is gradual, at least in Mediterranean-climate streams where drying is gradual. However, the changes may be more dramatic in arid and semiarid streams or in Mediterranean-climate streams if drying is rapid.

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Urban Regeneration. A challenge for Public Art, supposed the start of a trend of critical thought related to the topics of Public Art, Urban Regeneration and Urban Design. This trend agglutinated around the Public Art Observatory that, still today, develops its activities.The book gathers a series of critical proposals organized in the chapters " Art and Design in/for Public Space ", " Forms and Representations of Public Art/Public Space. The Producer/User Dilemma " and " Public Art / Cities in Competition: Strategies, Bridges and Gateways ", with the participation of, among others, Sergi Valera, Ray Smith, Martí Peran, Ian Rawlinson, Chaké Matosian, Enric Pol, J. Hyatt, J. Gingell or T. Bovaird.

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Climate change may pose challenges and opportunities to viticulture, and much research has focused in studying the likely impacts on grapes and wine production in different regions worldwide. This study assesses the vulnerability and adaptive capacity of the viticulture sector under changing climate conditions, based on a case study in El Penedès region, Catalonia. Farm assets, livelihood strategies, farmer-market interactions and climate changes perceptions are analysed through semi-structured interviews with different types of wineries and growers. Both types of actors are equally exposed to biophysical stressors but unevenly affected by socioeconomic changes. While wineries are vulnerable because of the current economic crisis and the lack of diversification of their work, which may affect their income or production, growers are mainly affected by the low prices of their products and the lack of fix contracts. These socioeconomic stressors strongly condition their capacity to adapt to climate change, meaning that growers prioritize their immediate income problems, rather than future socioeconomic or climate threats. Therefore, growers undertake reactive adaptation to climate changing conditions, mainly based on ancient knowledge, whilst wineries combine both reactive and anticipatory adaptation practices. These circumstances should be addressed in order to allow better anticipatory adaptation to be implemented, thus avoiding future climate threats.

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In the context of observed climate change impacts and their effect on agriculture and crop production, this study intends to assess the vulnerability of rural livelihoods through a study case in Karnataka, India. The social approach of climate change vulnerability in this study case includes defining and exploring factors that determine farmers’ vulnerability in four villages. Key informant interviews, farmer workshops and structured household interviews were used for data collection. To analyse the data, we adapted and applied three vulnerability indices: Livelihood Vulnerability Index (LVI), LVI-IPCC and the Livelihood Effect Index (LEI), and used descriptive statistical methods. The data was analysed at two scales: whole sample-level and household level. The results from applying the indices for the whole-sample level show that this community's vulnerability to climate change is moderate, whereas the household-level results show that most of the households' vulnerability is high-very high, while 15 key drivers of vulnerability were identified. Results and limitations of the study are discussed under the rural livelihoods framework, in which the indices are based, allowing a better understanding of the social behaviouraltrends, as well as an holistic and integrated view of the climate change, agriculture, and livelihoods processes shaping vulnerability. We conclude that these indices, although a straightforward method to assess vulnerability, have limitations that could account for inaccuracies and inability to be standardised for benchmarking, therefore we stress the need for further research.

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Ecosystems are complex systems and changing one of their components can alter their whole functioning. Decomposition and biodiversity are two factors that play a role in this stability, and it is vital to study how these two factors are interrelated and how other factors, whether of human origin or not, can affect them. This study has tested different hypotheses regarding the effects of pesticides and invasive species on the biodiversity of the soil fauna and litter decomposition rate. Decomposition was measured using the litterbags technique. Our results indicate that pesticides had a negative effect on decomposition whereas invasive species increased decomposition rate. At the same time, the diversity of the soil biota was unaffected by either factor. These results allow us to better understand the response of important ecosystem functions to human‐induced alterations, in order to mitigate harmful effects or restore them wherever necessary.