899 resultados para Urban land - Usage and occupancy
Resumo:
Toponomastics is increasingly interested in the subjective role of place names in quotidian life. In the frame of Urban Geography, the interest in this matter is currently growing, as the recently change in modes of habitation has urged our discipline to find new ways of exploring the cities. In this context, the study of how name's significance is connected to a urban society constitutes a very interesting approach. We believe in the importance of place names as tools for decoding urban areas and societies at a local-scale. This consideration has been frequently taken into account in the analysis of exonyms, although in their case they are not exempt of political and practical implications that prevail over the tool function. The study of toponomastic processes helps us understanding how the city works, by analyzing the liaison between urban landscape, imaginaries and toponyms which is reflected in the scarcity of some names, in the biased creation of new toponyms and in the pressure exercised over every place name by tourists, residents and local government for changing, maintaining or eliminating them. Our study-case, Toledo, is one of the oldest cities in Spain, full of myths, stories and histories that can only be understood combined with processes of internal evolution of the city linked to the arrival of new residents and the more and more notorious change of its historical landscape. At a local scale, we are willing to decode the information which is contained in its toponyms about its landscape and its society.
Resumo:
Soil erosion is a serious environmental threat in the Mediterranean region due to torrential rainfalls, and it contributes to the degradation of agricultural land. Techniques such as rainwater harvesting may improve soil water storage and increase agricultural productivity, which could result in more effective land usage. Reservoir tillage is an effective system of harvesting rainwater, but it has not been scientifically evaluated like other tillage systems. Its suitability for the conditions in Spain has not been determined. To investigate and quantify water storage from reservoir tillage and how it could be adapted to improve infiltration of harvested rainwater, a laboratory-scale rainfall simulator was developed. Rainfall characteristics, including rainfall intensity, spatial uniformity and raindrop size, confirm that natural rainfall conditions are simulated with sufficient accuracy. The simulator was auto-controlled by a solenoid valve and three pressure nozzles were used to spray water corresponding to five rainfall intensities ranging from 36 to 112 mm h-1 for 3 to 101-year return period with uniformity coefficients between 83 and 94%. In order to assess the reservoir tillage method under surface slopes of 0, 5, and 10%, three soil scooping devices with identical volume were used to make depressions in the following forms: a) truncated square pyramid, b) triangular prism, and c) truncated cone. These depressions were compared to a control soil surface with no depression. For the loam soil used in this study, results show that reservoir tillage was able to reduce soil erosion and surface runoff and significantly increase infiltration. There was significant difference between the depressions and the control. Compared to the control, depression (a) reduced surface runoff by about 61% and the sediment yield concentration by about 79%.
Resumo:
Accessibility is an essential concept widely used to evaluate the impact of land-use and transport strategies in transport and urban planning. Accessibility is typically evaluated by using a transport model or a land-use model independently or successively without a feedback loop, thus neglecting the interaction effects between the two systems and the induced competition effects among opportunities due to accessibility improvements. More than a mere methodological curiosity, failure to account for land- use/transport interactions and the competition effect may result in large underestimation of the policy effects. With the recent development of land-use and transport interaction (LUTI) models, there is a growing interest in using these models to adequately measure accessibility and evaluate its impact. The current study joins this research stream by embedding an accessibility measure in a LUTI model with two main aims. The first aim is to account for adaptive accessibility, namely the adjustment of the potential accessibility due to the effect of competition among opportunities (e.g., workplaces) as a result of improved accessibility. LUTI models are particularly suitable for assessing adaptive accessibility because the competition factor is a function of the number of jobs, which is related to land-use attractiveness and the number of workers which is related, among other factors, to the transport demand. The second aim is to identify the optimal implementation scenario of policy measures on the basis of the potential and adaptive accessibility and analyse the results in terms of social welfare and accessibility. The metropolitan area of Madrid is used as a case-study and two transport policy instruments, namely a cordon toll and bus frequency increase, have been chosen for the simulation study in order to present the usefulness of the approach to urban planners and policy makers. The MARS model (Metropolitan Activity Relocation Simulator) calibrated for Madrid was employed as the analysis tool. The impact of accessibility is embedded in the model through a social welfare function that includes not only costs and benefits to both road users and transport operators, but also costs and benefits for the government and society in general (external costs). An optimisation procedure is performed by the MARS model for maximizing the value of objective function in order to find the best (optimal) policy imp lementations intensity (i.e., price, frequency). Last, the two policy strategies are evaluated in terms of their accessibility. Results show that the accessibility with competition factor influences the optimal policy implementation level and also generates different results in terms of social welfare. In addition, mapping the difference between the potential and the adaptive accessibility indicators shows that the main changes occur in areas where there is a strong competition among land-use opportunities.
Resumo:
This article presents an alternative approach to the decision-making process in transport strategy design. The study explores the possibility of integrating forecasting, assessment and optimization procedures in support of a decision-making process designed to reach the best achievable scenario through mobility policies. Long-term evaluation, as required by a dynamic system such as a city, is provided by a strategic Land-Use and Transport Interaction (LUTI) model. The social welfare achieved by implementing mobility LUTI model policies is measured through a cost-benefit analysis and maximized through an optimization process throughout the evaluation period. The method is tested by optimizing a pricing policy scheme in Madrid on a cordon toll in a context requiring system efficiency, social equity and environmental quality. The optimized scheme yields an appreciable increase in social surplus through a relatively low rate compared to other similar pricing toll schemes. The results highlight the different considerations regarding mobility impacts on the case study area, as well as the major contributors to social welfare surplus. This leads the authors to reconsider the cost-analysis approach, as defined in the study, as the best option for formulating sustainability measures.
Resumo:
Una gestión más eficiente y equitativa del agua a escala de cuenca no se puede centrar exclusivamente en el recurso hídrico en sí, sino también en otras políticas y disciplinas científicas. Existe un consenso creciente de que, además de la consideración de las cambiantes condiciones climáticas, es necesaria una integración de ámbitos de investigación tales como la agronomía, planificación del territorio y ciencias políticas y económicas a fin de satisfacer de manera sostenible las demandas de agua por parte de la sociedad y del medio natural. La Política Agrícola Común (PAC) es el principal motor de cambio en las tendencias de paisajes rurales y sistemas agrícolas, pero el deterioro del medio ambiente es ahora una de las principales preocupaciones. Uno de los cambios más relevantes se ha producido con la expansión e intensificación del olivar en España, principalmente con nuevas zonas de regadío o la conversión de olivares de secano a sistemas en regadío. Por otra parte, el cambio de las condiciones climáticas podría ejercer un papel importante en las tendencias negativas de las aportaciones a los ríos, pero no queda claro el papel que podrían estar jugando los cambios de uso de suelo y cobertura vegetal sobre las tendencias negativas de caudal observadas. Esta tesis tiene como objetivo mejorar el conocimiento de los efectos de la producción agrícola, política agraria y cambios de uso de suelo y cobertura vegetal sobre las condiciones de calidad del agua, respuesta hidrológica y apropiación del agua por parte de la sociedad. En primer lugar, el estudio determina las tendencias existentes de nitratos y sólidos en suspensión en las aguas superficiales de la cuenca del río Guadalquivir durante el periodo de 1998 a 2009. Desde una perspectiva de política agraria, la investigación trata de evaluar mediante un análisis de datos de panel las principales variables, incluyendo la reforma de la PAC de 2003, que están teniendo una influencia en ambos indicadores de calidad. En segundo lugar, la apropiación del agua y el nivel de contaminación por nitratos debido a la producción del aceite de oliva en España se determinan con una evaluación de la huella hídrica (HH), teniendo en cuenta una variabilidad espacial y temporal a largo de las provincias españolas y entre 1997 y 2008. Por último, la tesis analiza los efectos de los cambios de uso de suelo y cobertura vegetal sobre las tendencias negativas observadas en la zona alta del Turia, cabecera de la cuenca del río Júcar, durante el periodo 1973-2008 mediante una modelización ecohidrológica. En la cuenca del Guadalquivir cerca del 20% de las estaciones de monitoreo muestran tendencias significativas, lineales o cuadráticas, para cada indicador de calidad de agua. La mayoría de las tendencias significativas en nitratos están aumentando, y la mayoría de tendencias cuadráticas muestran un patrón en forma de U. Los modelos de regresión de datos de panel muestran que las variables más importantes que empeoran ambos indicadores de calidad del agua son la intensificación de biomasa y las exportaciones de ambos indicadores de calidad procedentes de aguas arriba. En regiones en las que el abandono agrícola y/o desintensificación han tenido lugar han mejorado las condiciones de calidad del agua. Para los nitratos, el desacoplamiento de las subvenciones a la agricultura y la reducción de la cuantía de las subvenciones a tierras de regadío subyacen en la reducción observada de la concentración de nitratos. Las medidas de modernización de regadíos y el establecimiento de zonas vulnerables a nitratos reducen la concentración en subcuencas que muestran una tendencia creciente de nitratos. Sin embargo, el efecto de las exportaciones de nitratos procedente de aguas arriba, la intensificación de la biomasa y los precios de los cultivos presentan un mayor peso, explicando la tendencia creciente observada de nitratos. Para los sólidos en suspensión, no queda de forma evidente si el proceso de desacoplamiento ha influido negativa o positivamente. Sin embargo, los mayores valores de las ayudas agrarias aún ligadas a la producción, en particular en zonas de regadío, conllevan un aumento de las tasas de erosión. Aunque la cuenca del Guadalquivir ha aumentado la producción agrícola y la eficiencia del uso del agua, el problema de las altas tasas de erosión aún no ha sido mitigado adecuadamente. El estudio de la huella hídrica (HH) revela que en 1 L de aceite de oliva español más del 99,5% de la HH está relacionado con la producción de la aceituna, mientras que menos del 0,5% se debe a otros componentes, es decir, a la botella, tapón y etiqueta. Durante el período estudiado, la HH verde en secano y en regadío representa alrededor del 72% y 12%, respectivamente, del total de la HH. Las HHs azul y gris representan 6% y 10%, respectivamente. La producción de aceitunas se concentra en regiones con una HH menor por unidad de producto. La producción de aceite de oliva ha aumentado su productividad del agua durante 1997-2008, incentivado por los crecientes precios del aceite, como también lo ha hecho la cantidad de exportaciones de agua virtual. De hecho, las mayores zonas productoras presentan una eficiencia alta del uso y de productividad del agua, así como un menor potencial de contaminación por nitratos. Pero en estas zonas se ve a la vez reflejado un aumento de presión sobre los recursos hídricos locales. El aumento de extracciones de agua subterránea relacionadas con las exportaciones de aceite de oliva podría añadir una mayor presión a la ya estresada cuenca del Guadalquivir, mostrando la necesidad de equilibrar las fuerzas del mercado con los recursos locales disponibles. Los cambios de uso de suelo y cobertura vegetal juegan un papel importante en el balance del agua de la cuenca alta del Turia, pero no son el principal motor que sustenta la reducción observada de caudal. El aumento de la temperatura es el principal factor que explica las mayores tasas de evapotranspiración y la reducción de caudales. Sin embargo, los cambios de uso de suelo y el cambio climático han tenido un efecto compensatorio en la respuesta hidrológica. Por un lado, el caudal se ha visto afectado negativamente por el aumento de la temperatura, mientras que los cambios de uso de suelo y cobertura vegetal han compensado positivamente con una reducción de las tasas de evapotranspiración, gracias a los procesos de disminución de la densidad de matorral y de degradación forestal. El estudio proporciona una visión que fortalece la interdisciplinariedad entre la planificación hidrológica y territorial, destacando la necesidad de incluir las implicaciones de los cambios de uso de suelo y cobertura vegetal en futuros planes hidrológicos. Estos hallazgos son valiosos para la gestión de la cuenca del río Turia, y el enfoque empleado es útil para la determinación del peso de los cambios de uso de suelo y cobertura vegetal en la respuesta hidrológica en otras regiones. ABSTRACT Achieving a more efficient and equitable water management at catchment scale does not only rely on the water resource itself, but also on other policies and scientific knowledge. There is a growing consensus that, in addition to consideration of changing climate conditions, integration with research areas such as agronomy, land use planning and economics and political science is required to meet sustainably the societal and environmental water demands. The Common Agricultural Policy (CAP) is a main driver for trends in rural landscapes and agricultural systems, but environmental deterioration is now a principal concern. One of the most relevant changes has occurred with the expansion and intensification of olive orchards in Spain, taking place mainly with new irrigated areas or with the conversion from rainfed to irrigated systems. Moreover, changing climate conditions might exert a major role on water yield trends, but it remains unclear the role that ongoing land use and land cover changes (LULCC) might have on observed river flow trends. This thesis aims to improve the understanding of the effects of agricultural production, policies and LULCC on water quality conditions, hydrological response and human water appropriation. Firstly, the study determines the existing trends for nitrates and suspended solids in the Guadalquivir river basin’s surface waters (south Spain) during the period from 1998 to 2009. From a policy perspective, the research tries to assess with panel data analysis the main drivers, including the 2003 CAP reform, which are having an influence on both water quality indicators. Secondly, water appropriation and nitrate pollution level originating from the production of olive oil in Spain is determined with a water footprint (WF) assessment, considering a spatial temporal variability across the Spanish provinces and from 1997 to 2008 years. Finally, the thesis analyzes the effects of the LULCC on the observed negative trends over the period 1973-2008 in the Upper Turia basin, headwaters of the Júcar river demarcation (east Spain), with ecohydrological modeling. In the Guadalquivir river basin about 20% of monitoring stations show significant trends, linear or quadratic, for each water quality indicator. Most significant trends of nitrates are augmenting than decreasing, and most significant quadratic terms of both indicators exhibit U-shaped patterns. The panel data models show that the most important drivers that are worsening nitrates and suspended solids in the basin are biomass intensification and exports of both water quality indicators from upland regions. In regions that agricultural abandonment and/or de-intensification have taken place the water quality conditions have improved. For nitrates, the decoupling of agricultural subsidies and the reduction of the amount of subsidies to irrigated land underlie the observed reduction of nitrates concentration. Measures of irrigation modernization and establishment of vulnerable zones to nitrates ameliorate the concentration of nitrates in subbasins showing an increasing trend. However, the effect of nitrates load from upland areas, intensification of biomass and crop prices present a greater weight leading to the final increasing trend in this subbasins group, where annual crops dominate. For suspended solids, there is no clear evidence that decoupling process have influenced negatively or positively. Nevertheless, greater values of subsidies still linked to production, particularly in irrigated regions, lead to increasing erosion rates. Although agricultural production has augmented in the basin and water efficiency in the agricultural sector has improved, the issue of high erosion rates has not yet been properly faced. The water footprint (WF) assessment reveals that for 1 L Spanish olive oil more than 99.5% of the WF is related to the olive fruit production, whereas less than 0.5% is due to other components i.e. bottle, cap and label. Over the studied period, the green WF in rainfed and irrigated systems represents about 72% and 12%, respectively, of the total WF. Blue and grey WFs represent 6% and 10%, respectively. The olive production is concentrated in regions with the smallest WF per unit of product. The olive oil production has increased its apparent water productivity from 1997 to 2008 incentivized by growing trade prices, but also did the amount of virtual water exports. In fact, the largest producing areas present high water use efficiency per product and apparent water productivity as well as less nitrates pollution potential, but this enhances the pressure on the available water resources. Increasing groundwater abstractions related to olive oil exports may add further pressure to the already stressed Guadalquivir basin. This shows the need to balance the market forces with the available local resources. Concerning the effects of LULCC on the Upper Turia basin’s streamflow, LULCC play a significant role on the water balance, but it is not the main driver underpinning the observed reduction on Turia's streamflow. Increasing mean temperature is the main factor supporting larger evapotranspiration rates and streamflow reduction. In fact, LULCC and climate change have had an offsetting effect on the streamflow generation during the study period. While streamflow has been negatively affected by increasing temperature, ongoing LULCC have positively compensated with reduced evapotranspiration rates, thanks to mainly shrubland clearing and forest degradation processes. The research provides insight for strengthening the interdisciplinarity between hydrological and spatial planning, highlighting the need to include the implications of LULCC in future hydrological plans. These findings are valuable for the management of the Turia river basin, as well as a useful approach for the determination of the weight of LULCC on the hydrological response in other regions.
Resumo:
Water is fundamental to human life and the availability of freshwater is often a constraint on human welfare and economic development. Consequently, the potential effects of global changes on hydrology and water resources are considered among the most severe and vital ones. Water scarcity is one of the main problems in the rural communities of Central America, as a result of an important degradation of catchment areas and the over-exploitation of aquifers. The present Thesis is focused on two critical aspects of global changes over water resources: (1) the potential effects of climate change on water quantity and (2) the impacts of land cover and land use changes on the hydrological processes and water cycle. Costa Rica is among the few developing countries that have recently achieved a land use transition with a net increase in forest cover. Osa Region in South Pacific Costa Rica is an appealing study site to assess water supply management plans and to measure the effects of deforestation, forest transitions and climate change projections reported in the region. Rural Community Water Supply systems (ASADAS) in Osa are dealing with an increasing demand of freshwater due to the growing population and the change in the way of life in the rural livelihoods. Land cover mosaics which have resulted from the above mentioned processes are characterized by the abandonment of marginal farmland with the spread over these former grasslands of high return crops and the expansion of secondary forests due to reforestation initiatives. These land use changes have a significant impact on runoff generation in priority water-supply catchments in the humid tropics, as evidenced by the analysis of the Tinoco Experimental Catchment in the Southern Pacific area of Costa Rica. The monitoring system assesses the effects of the different land uses on the runoff responses and on the general water cycle of the basin. Runoff responses at plot scale are analyzed for secondary forests, oil palm plantations, forest plantations and grasslands. The Oil palm plantation plot presented the highest runoff coefficient (mean RC=32.6%), twice that measured under grasslands (mean RC=15.3%) and 20-fold greater than in secondary forest (mean RC=1.7%). A Thornthwaite-type water balance is proposed to assess the impact of land cover and climate change scenarios over water availability for rural communities in Osa Region. Climate change projections were obtained by the downscaling of BCM2, CNCM3 and ECHAM5 models. Precipitation and temperature were averaged and conveyed by the A1B, A2 and B1 IPCC climate scenario for 2030, 2060 and 2080. Precipitation simulations exhibit a positive increase during the dry season for the three scenarios and a decrease during the rainy season, with the highest magnitude (up to 25%) by the end of the 21st century under scenario B1. Monthly mean temperature simulations increase for the three scenarios throughout the year with a maximum increase during the dry season of 5% under A1B and A2 scenarios and 4% under B1 scenario. The Thornthwaite-type Water Balance model indicates important decreases of water surplus for the three climate scenarios during the rainy season, with a maximum decrease on May, which under A1B scenario drop up to 20%, under A2 up to 40% and under B1 scenario drop up to almost 60%. Land cover scenarios were created taking into account current land cover dynamics of the region. Land cover scenario 1 projects a deforestation situation, with forests decreasing up to 15% due to urbanization of the upper catchment areas; land cover scenario 2 projects a forest recovery situation where forested areas increase due to grassland abandonment on areas with more than 30% of slope. Deforestation scenario projects an annual water surplus decrease of 15% while the reforestation scenario projects a water surplus increase of almost 25%. This water balance analysis indicates that climate scenarios are equal contributors as land cover scenarios to future water resource estimations.
Resumo:
Channel cbanges are the consequence of cbanges in sediment yield from the slopes and in the connectivity between slopes and channels bccause of distinct land use and climate inJpacts. In Ibis study, we investigated the characteristics and evolution of a short reach in the headwater of the !juez River, central-soutbem Pyrenees. Assessment of a series of sedimentar)' and geomorphic structures confirtned major cbanges to the valley boUom, mainly related to changes in the intensity of human activity. 'The oldest sedimentar)' structure is a terrace leve! located 3 10 4 m above the current alluvial plain. General deforestation, overgrazing and recwring tires in the montane belt ( 1100-1600 m a.sJ.) have led 10 increased soil erosioo and connectivity, and to tbe triggering of debris llows thal have been deposited on the fluvial tmace. Woody fragments from within the debris llows were dated using acceleraror mass spectrOmetry '"e radiocaroon tcchniques (AMS), yielding ages between 1 00 and 115 cal years BP, whicb coincides with tbe period of maximum deforestalion and human density in the Pyrenees. Depopulation and fannland abaodonment since tbe beginning of tbe 2001 oenrury has resulled in generalliJcod natural and artificial reforestation, a shrinkage of the eroded arcas aod a decline in connectivi¡y bdween slopes and the channel. 1be rnost impor1an1 consequence has been cbannel incision and oarrowing, and the development of a sedimed annour !ayer. Active sedimenl b8llSpOI1 is continui.Qg, although there has been a decrease in sed.iment yield from the slopes. Copyright O 2014 John Wiley & Soos, Ltd.
Resumo:
Soil erosion is a serious environmental threat in the Mediterranean region due to torrential rainfalls, and it contributes to the degradation of agricultural land. Techniques such as rainwater harvesting may improve soil water storage and increase agricultural productivity, which could result in more effective land usage. Reservoir tillage is an effective system of harvesting rainwater, but it has not been scientifically evaluated like other tillage systems. Its suitability for the conditions in Spain has not been determined. To investigate and quantify water storage from reservoir tillage and how it could be adapted to improve infiltration of harvested rainwater, a laboratory-scale rainfall simulator was developed. Rainfall characteristics, including rainfall intensity, spatial uniformity and raindrop size, confirm that natural rainfall conditions are simulated with sufficient accuracy. The simulator was auto-controlled by a solenoid valve and three pressure nozzles were used to spray water corresponding to five rainfall intensities ranging from 36 to 112 mm h− 1 for 3 to 101-year return period with uniformity coefficients between 83 and 94%. In order to assess the reservoir tillage method under surface slopes of 0, 5, and 10%, three soil scooping devices with identical volume were used to make depressions in the following forms: a) truncated square pyramid, b) triangular prism, and c) truncated cone. These depressions were compared to a control soil surface with no depression. For the loam soil used in this study, results show that reservoir tillage was able to reduce soil erosion and surface runoff and significantly increase infiltration. There was significant difference between the depressions and the control. Compared to the control, depression (a) reduced surface runoff by about 61% and the sediment yield concentration by about 79%.
Resumo:
In order to minimize car-based trips, transport planners have been particularly interested in understanding the factors that explain modal choices. Transport modelling literature has been increasingly aware that socioeconomic attributes and quantitative variables are not sufficient to characterize travelers and forecast their travel behavior. Recent studies have also recognized that users’ social interactions and land use patterns influence travel behavior, especially when changes to transport systems are introduced; but links between international and Spanish perspectives are rarely dealt with. The overall objective of the thesis is to develop a stepped methodology that integrate diverse perspectives to evaluate the willingness to change patterns of urban mobility in Madrid, based on four steps: (1st) analysis of causal relationships between both objective and subjective personal variables, and travel behavior to capture pro-car and pro-public transport intentions; (2nd) exploring the potential influence of individual trip characteristics and social influence variables on transport mode choice; (3rd) identifying built environment dimensions on travel behavior; and (4th) exploring the potential influence on transport mode choice of extrinsic characteristics of individual trip using panel data, land use variables using spatial characteristics and social influence variables. The data used for this thesis have been collected from a two panel smartphone-based survey (n=255 and 190 respondents, respectively) carried out in Madrid. Although the steps above are mainly methodological, the application to the area of Madrid allows deriving important results that can be directly used to forecast travel demand and to evaluate the benefits of specific policies that might be implemented in the area. The results demonstrated, respectively: (1st) transport policy actions are more likely to be effective when pro-car intention has been disrupted first; (2nd) the consideration of “helped” and “voluntary” users as tested here could have a positive and negative impact, respectively, on the use of public transport; (3rd) the importance of density, design, diversity and accessibility underlying dimensions responsible for land use variables; and (4th) there are clearly different types of combinations of social interactions, land use and time frame on travel behavior studies. Finally, with the objective to study the impact of demand measures to change urban mobility behavior, those previous results have been considered in a unique way, a hybrid discrete choice model has been used on a 5th step. Then it can be concluded that urban mobility behavior is not only ruled by the maximum utility criterion, but also by a strong psychological-environment concept, developed without the mediation of cognitive processes during choice, i.e., many people using public transport on their way to work do not do it for utilitarian reasons, but because no other choice is available. Regarding built environment dimensions, the more diversity place of residence, the more difficult the use of public transport or walking.
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Recent research has shown large differences between the expected and the actual energy consumption in buildings. The differences have been attributed partially, to the assumptions made during the design phase of buildings when simulation methods are employed. More accurate occupancy profiles on building operation could help to carry out more precise building performance calculations. This study focuses on the post-occupancy evaluation of two apartments, one renovated and one non renovated, in Madrid within the same building complex. The aim of this paper is to present an application of the mixed-methods methodology (Creswell, 2007) to assess thermal comfort and occupancy practices used in the case studies, and to discuss the shortcomings and opportunities associated with it. The mixed-methods methodology offers strategies for integrating qualitative and quantitative methods to investigate complex phenomena. This approach is expected to contribute to the growing knowledge of occupants’ behaviour and building performance by explaining the differences observed between energy consumption and thermal comfort in relation to people’s saving and comfort practices and the related experiences, preferences and values.
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En las últimas tres décadas, las dinámicas de restructuración económica a nivel global han redefinido radicalmente el papel de las ciudades. La transición del keynesianismo al neoliberalismo ha provocado un cambio en las políticas urbanas de los gobiernos municipales, que han abandonado progresivamente las tareas de regulación y redistribución para centrarse en la promoción del crecimiento económico y la competitividad. En este contexto, muchas voces críticas han señalado que la regeneración urbana se ha convertido en un vehículo de extracción de valor de la ciudad y está provocando la expulsión de los ciudadanos más vulnerables. Sin embargo, la regeneración de áreas consolidadas supone también una oportunidad de mejora de las condiciones de vida de la población residente, y es una política necesaria para controlar la expansión de la ciudad y reducir las necesidades de desplazamiento, promoviendo así ciudades más sostenibles. Partiendo de la hipótesis de que la gobernanza de los procesos de regeneración urbana es clave en el resultado final de las operaciones y determina el modelo de ciudad resultante, el objetivo de esta investigación es verificar si la regeneración urbana es necesariamente un mecanismo de extracción de valor o si puede mejorar la calidad de vida en las ciudades a través de la participación de los ciudadanos. Para ello, propone un marco de análisis del proceso de toma de decisiones en los planes de regeneración urbana y su impacto en los resultados de los planes, tomando como caso de estudio la ciudad de Boston, que desde los años 1990 trata de convertirse en una “ciudad de los barrios”, fomentando la participación ciudadana al tiempo que se posiciona en la escena económica global. El análisis se centra en dos operaciones de regeneración iniciadas a finales de los años 1990. Por un lado, el caso de Jackson Square nos permite comprender el papel de la sociedad civil y el tercer sector en la regeneración de los barrios más desfavorecidos, en un claro ejemplo de urbanismo “desde abajo” (bottom-up planning). Por otro, la reconversión del frente marítimo de South Boston para la construcción del Distrito de Innovación nos acerca a las grandes operaciones de regeneración urbana con fines de estímulo económico, tradicionalmente vinculadas a los centros financieros (downtown) y dirigidas por las élites gubernamentales y económicas (la growth machine) a través de procesos más tecnocráticos (top-down planning). La metodología utilizada consiste en el análisis cualitativo de los procesos de toma de decisiones y la relación entre los agentes implicados, así como de la evaluación de la implementación de dichas decisiones y su influencia en el modelo urbano resultante. El análisis de los casos permite afirmar que la gobernanza de los procesos de regeneración urbana influye decisivamente en el resultado final de las intervenciones; sin embargo, la participación de la comunidad local en la toma de decisiones no es suficiente para que el resultado de la regeneración urbana contrarreste los efectos de la neoliberalización, especialmente si se limita a la fase de planeamiento y no se extiende a la fase de ejecución, y si no está apoyada por una movilización política de mayor alcance que asegure una acción pública redistributiva. Asimismo, puede afirmarse que los procesos de regeneración urbana suponen una redefinición del modelo de ciudad, dado que la elección de los espacios de intervención tiene consecuencias sobre el equilibrio territorial de la ciudad. Los resultados de esta investigación tienen implicaciones para la disciplina del planeamiento urbano. Por una parte, se confirma la vigencia del paradigma del “urbanismo negociado”, si bien bajo discursos de liderazgo público y sin apelación al protagonismo del sector privado. Por otra parte, la planificación colaborativa en un contexto de “responsabilización” de las organizaciones comunitarias puede desactivar la potencia política de la participación ciudadana y servir como “amortiguador” hacia el gobierno local. Asimismo, la sustitución del planeamiento general como instrumento de definición de la ciudad futura por una planificación oportunista basada en la actuación en áreas estratégicas que tiren del resto de la ciudad, no permite definir un modelo coherente y consensuado de la ciudad que se desea colectivamente, ni permite utilizar el planeamiento como mecanismo de redistribución. ABSTRACT In the past three decades, the dynamics of global economic restructuring have radically redefined the role of cities. The transition from keynesianism to neoliberalism has caused a shift in local governments’ urban policies, which have progressively abandoned the tasks of regulation and redistribution to focus on promoting economic growth and competitiveness. In this context, many critics have pointed out that urban regeneration has become a vehicle for extracting value from the city and is causing the expulsion of the most vulnerable citizens. However, regeneration of consolidated areas is also an opportunity to improve the living conditions of the resident population, and is a necessary policy to control the expansion of the city and reduce the need for transportation, thus promoting more sustainable cities. Assuming that the governance of urban regeneration processes is key to the final outcome of the plans and determines the resulting city model, the goal of this research is to verify whether urban regeneration is necessarily a value extraction mechanism or if it can improve the quality of life in cities through citizens’ participation. It proposes a framework for analysis of decision-making in urban regeneration processes and their impact on the results of the plans, taking as a case study the city of Boston, which since the 1990s is trying to become a "city of neighborhoods", encouraging citizen participation, while seeking to position itself in the global economic scene. The analysis focuses on two redevelopment plans initiated in the late 1990s. The Jackson Square case allows us to understand the role of civil society and the third sector in the regeneration of disadvantaged neighborhoods, in a clear example of bottom-up planning. On the contrary, the conversion of the South Boston waterfront to build the Innovation District takes us to the big redevelopment efforts with economic stimulus’ goals, traditionally linked to downtowns and led by government and economic elites (the local “growth machine”) through more technocratic processes (top-down planning). The research is based on a qualitative analysis of the processes of decision making and the relationship between those involved, as well as the evaluation of the implementation of those decisions and their influence on the resulting urban model. The analysis suggests that the governance of urban regeneration processes decisively influences the outcome of interventions; however, community engagement in the decision-making process is not enough for the result of the urban regeneration to counteract the effects of neoliberalization, especially if it is limited to the planning phase and does not extend to the implementation of the projects, and if it is not supported by a broader political mobilization to ensure a redistributive public action. Moreover, urban regeneration processes redefine the urban model, since the choice of intervention areas has important consequences for the territorial balance of the city. The results of this study have implications for the discipline of urban planning. On the one hand, it confirms the validity of the "negotiated planning" paradigm, albeit under public leadership discourse and without a direct appeal to the leadership role of the private sector. On the other hand, collaborative planning in a context of "responsibilization" of community based organizations can deactivate the political power of citizen participation and serve as a "buffer" towards the local government. Furthermore, the replacement of comprehensive planning, as a tool for defining the city's future, by an opportunistic planning based on intervention in strategic areas that are supposed to induce change in the rest of the city, does not allow a coherent and consensual urban model that is collectively desired, nor it allows to use planning as a redistribution mechanism.
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The urban microclimate plays an important role in building energy consumption and thermal comfort in outdoor spaces. Nowadays, cities need to increase energy efficiency, reduce pollutant emissions and mitigate the evident lack of sustainability. In light of this, attention has focused on the bioclimatic concepts use in the urban development. However, the speculative unsustainability of the growth model highlights the need to redirect the construction sector towards urban renovation using a bioclimatic approach. The public space plays a key role in improving the quality of today’s cities, especially in terms of providing places for citizens to meet and socialize in adequate thermal conditions. Thermal comfort affects perception of the environment, so microclimate conditions can be decisive for the success or failure of outdoor urban spaces and the activities held in them. For these reasons, the main focus of this work is on the definition of bioclimatic strategies for existing urban spaces, based on morpho-typological components, urban microclimate conditions and comfort requirements for all kinds of citizens. Two case studies were selected in Madrid, in a social housing neighbourhood constructed in the 1970s based on Rational Architecture style. Several renovation scenarios were performed using a computer simulation process based in ENVI-met and diverse microclimate conditions were compared. In addition, thermal comfort evaluation was carried out using the Universal Thermal Climate Index (UTCI) in order to investigate the relationship between microclimate conditions and thermal comfort perception. This paper introduces the microclimate computer simulation process as a valuable support for decision-making for neighbourhood renovation projects in order to provide new and better solutions according to the thermal quality of public spaces and reducing energy consumption by creating and selecting better microclimate areas.
Resumo:
Black South Africans experienced centuries of mistreatment and land dispossessions, leaving their population in dire poverty and dependence. The 1994 democratization of South Africa birthed a three-fold land reform program dedicated to land restitution, land redistribution, and tenure reform. The first decade of implementation left government goals unmet. The relevance of land reform is examined given modern-day urbanization, industrialization, and globalization. This paper affirms land reform is still relevant socially and is therefore relevant politically and economically. Improvements to program implementation are suggested in the following areas: implementing agency support; rural representation; information management; land market stimulation; beneficiary support; and agrarian reform. Land reform limitations are discussed, and industrialization is briefly explored as the more likely solution to poverty issues.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Map of New-York Bay and Harbor and the environs : sheet no. 2, founded upon a trigonometrical survey under the direction of F.R. Hassler, superintendent of the Survey of the Coast of the United States ; triangulation by James Ferguson and Edmund Blunt, assistants ; the hydrography under the direction of Thomas R. Gedney, lieutenant U.S. Navy ; the topography by C. Renard and T.A. Jenkins assists. It was published by Survey of the Coast of the United States in 1844-1845. Scale 1:30,000. This layer is image 2 of 6 total images of the six sheet source map, representing the southeast portion of the map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Universal Transverse Mercator (UTM) Zone 18N NAD83 projection. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, or other information associated with the principal map. This map shows coastal features such as lighthouses, buoys, beacons, rocks, channels, points, coves, islands, bottom soil types, wharves, and more. Includes also selected land features such as roads, drainage, land cover, forts, selected buildings, towns, and more. Relief shown by hachures. Depths are shown by soundings and shading. Includes text, table of currents and stations, notes, sailing directions, 4 coastal panoramas and 2 views of Sandy Hook Light. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Map of New-York Bay and Harbor and the environs : sheet no. 1, founded upon a trigonometrical survey under the direction of F.R. Hassler, superintendent of the Survey of the Coast of the United States ; triangulation by James Ferguson and Edmund Blunt, assistants ; the hydrography under the direction of Thomas R. Gedney, lieutenant U.S. Navy ; the topography by C. Renard and T.A. Jenkins assists. It was published by Survey of the Coast of the United States in 1844-1845. Scale 1:30,000. This layer is image 1 of 6 total images of the six sheet source map, representing the southwest portion of the map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Universal Transverse Mercator (UTM) Zone 18N NAD83 projection. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, or other information associated with the principal map. This map shows coastal features such as lighthouses, buoys, beacons, rocks, channels, points, coves, islands, bottom soil types, wharves, and more. Includes also selected land features such as roads, drainage, land cover, forts, selected buildings, towns, and more. Relief shown by hachures. Depths are shown by soundings and shading. Includes text, table of currents and stations, notes, sailing directions, 4 coastal panoramas and 2 views of Sandy Hook Light. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.