2,434 research outputs found
Boundaries as tools for sustainable water management
Accross river basins water can have different types of values according not only to its production costs but also due to changes in the willingness to pay across the territory. The generalized view that integrated water management must be made through a centralised mechanism does not consider those facts and often assumes that command and control policies are the only tool available and effective. Therefore the functioning of river basins tend to be symplified with dams and the reserach agenda has been directed to design major models with powerful decision support systems for one coordinator body to decide. Nevertheless the effects of these centralised and controled systems has not been able to address the impredictability of human and ecosystem behaviour. The hypothesis we would like to test is that boundaries and negotiation between boundaries can be good tools for sustainable water management. First we review the literature on cases of basins' manegement trying to discuss the relation between boundaries. Then we develop a formal model with upstream and downstream regions and try to understand in what conditions boundaries can be good for sustainable water management. Finaly we try to introduce the concept of boundaries in an applied model for a particular river basin and simulate the solutions for a centralised planning body and for a descentralised negotiation system.
The morphotectonics offshore Southwest Iberia and the origin and evolution of the South Portuguese submarine canyons
Tese de doutoramento, Geologia (Geodinâmica Interna), Universidade de Lisboa, Faculdade de Ciências, 2012Fundação para a Ciência e a Tecnologia (FCT, SFRH/BD/17603/2004
On Applying Unit Propagation-Based Lower Bounds in Pseudo-Boolean Optimization
Unit propagation-based (UP) lower bounds are used in the vast majority of current Max-SAT solvers. However, lower bounds based on UP have seldom been applied in Pseudo-Boolean Optimization (PBO) algorithms derived from the DPLL procedure for Propositional Satisfiability (SAT). This paper enhances a DPLL-style PBO algorithm with an UP lower bound, and establishes conditions that enable constraint learning and non-chronological backtracking in the presence of conflicts involving constraints generated by the UP lower bound. From a theorical point of view, the paper highlights the relationship between the recent UP lower bound and the well-known Maximum Independent Set (MIS) lower bound. Finally, the paper provides preliminary results that show the effectiveness of the proposed approach for representative sets of instances
Exchange rate between scientific currencies - An application to the landuse plan of natura 2000
Science is driven by research funds, research funds are associated with decision making, and decision making is attached to valuation. Therefore every scientific paradigm tend to devise its own valuation system. Ecconomists prefer cost benefit analysis where everything can be translated into money. Planners assume values to infinity which lines in a map difining restrictions and enforceable land uses. Ecologists design maps with values for biodiversity. Historians value things according to their age. And engineers enjoy the mathematical control over multicriteria analysis. Anyway, concerning spatial planinng, most of the time there is a line on a map, assumed by polititions and experts and more or less respected by stakeholders. Along this line the total value of alternative uses must be the same. And the total value assumes all the infomation values provided by economists, ecologists, planners, engineers and historians. Because a line has many points it is possible to estimate the exchange rate function between all these different scientific currencies and derive the total economic value of different land uses.
Using yield gap analysis to give sustainable intensification local meaning
Yield gap analysis is useful to understand the relative contribution of growth-defining, -limiting and -reducing factors to actual yields. This is traditionally performed at the field level using mechanistic crop growth simulation models, and directly up-scaled to the regional and global levels without considering a range of factors intersecting at farm and farming system levels. As an example, these may include farmers' objectives and resource constraints, farm(er) characteristics, rotational effects between subsequent crops or decisions on resource allocation and prioritization of crop management. The objective of this thesis is to gain insights into yield gaps from a farm(ing) systems perspective in order to identify opportunities for sustainable intensification at local level. Three contrasting case studies representing a gradient of intensification and capturing a diversity of agricultural systems were selected for this purpose, namely mixed crop-livestock systems in Southern Ethiopia, rice based-farming systems in Central Luzon (Philippines) and arable farming systems in the Netherlands. A theoretical framework combining concepts of production ecology and methods of frontier analysis was developed to decompose yield gaps into efficiency, resource and technology yield gaps. This framework was applied and tested for the major crops in each case study using crop-specific input-output data for a large number of individual farms. In addition, different statistical methods and data analyses techniques were used in each case study to understand the contribution of farmers' objectives, farm(er) characteristics, cropping frequency and resource constraints to yield gaps and management practices at crop level. Yield gaps were largest for maize and wheat in Southern Ethiopia (ca. 80\\% of the water-limited yield), intermediate for rice in Central Luzon (ca. 50\\% of the climatic potential yield) and smallest for the major arable crops in the Netherlands (ca. 30\\% of the climatic potential yield). The underlying causes of these yield gaps also differed per case study. The technology yield gap explained most of the yield gap observed in Southern Ethiopia, which points to a lack of adoption of technologies able to reach the water-limited yield. The efficiency yield gap was most important for different arable crops in the Netherlands, which suggests a sub-optimal timing, space and form of the inputs applied. The three intermediate yield gaps contributed similarly to the rice yield gap in Central Luzon meaning that sub-optimal quantities of inputs used are as important in this case study as the causes mentioned for the other case studies. Narrowing the yield gap of the major crops does not seem to entail trade-offs with gross margin per unit land in each case study. However, the opposite seems to be true for N use efficiency and labour productivity particularly in Southern Ethiopia and Central Luzon, and to a less extent in the Netherlands. This means that (sustainable) intensification of smallholder agriculture in the tropics needs to go hand-in-hand with agronomic interventions that increase land productivity while ensuring high resource use efficiency and with labour-saving technologies that can reduce the drudgery of farming without compromising crop yields. Other insights at farm(ing) system level were clearer in Southern Ethiopia than in Central Luzon or in the Netherlands. For example, alleviating capital constraints was positively associated with intensification of maize-based farming systems around Hawassa and increases in oxen ownership (an indicator of farm power) was associated with extensification of wheat-based farming systems around Asella. In Central Luzon, farm and regional factors did not lead to different levels of intensification within the variation of rice farms investigated and the most striking effect was that direct-seeding (and thus slightly lower rice yields) was mostly adopted in larger farms, and used lower amounts of hired labour, compared to transplanting. In the Netherlands, the analysis of rotational effects on crop yields provided inconclusive results but confounding effects with e.g. rented land do not allow to conclude that these are not at stake in this farming system. This thesis broadens the discussion on yield gaps by moving from the technical aspects underlying their estimation towards the broader farm level opportunities and constraints undermining their closure. Overall, insights from contrasting case studies support conventional wisdom that intensification of agriculture needs to occur in the 'developing South', where yield gaps are large and resource use efficiency low, while a focus on improving sustainability based on sustainable intensification (or even extensification) is more appropriate in the 'developed North', where yield gaps are small and resource use efficiency high.</p
Demographic Sustainability and Regional Development: The Cases of Alto Minho and Alto Alentejo
Demographic Sustainability and Regional Development: The Cases of Alto Minho and Alto Alentejo Maria Nazaré Oliveira Roca, Vasco Silva, Susana Caldinhas Centro de Estudos de Geografia e Planeamento Regional, Universidade Nova de Lisboa The paper is focused on the interrelationship of the demographic resources and sustainable development, illustrated by the case studies of two regions of Portugal: Alto Minho and Alto Alentejo. In the introduction, some concepts related to demographic sustainability and rural development are discussed. In the following sections, the main features of the two sub-regions and a brief diagnosis of the population structure and dynamics are presented. This serve as the basis for the identification of the strengths and weaknesses as well as of the opportunities and threats related to demographic sustainability of those regions. In the conclusion guideline for promoting sustainable development of Alto Minho and Alto Alentejo are presented.
A comparison of two methods for the definition of Regional Metropolitan Areas through an application in the North of Portugal
The objective of this paper is to present a comparison of two methods for the definition of regional metropolitan areas, in a perspective of identification of urban territories with similar characteristics. In this study it is assumed that population density is, in the absence of another measure that describe daily or weekly individual movements, a variable that can be used to evaluate, although indirectly, the activity level and dynamics of the territory. The first method explored here uses ESDA (Exploratory Spatial Data Analyses) techniques for the definition of regional metropolitan areas. The second method is based on an index value that results from a rank of the variable under analysis in a spatial context, both at the local and national (or regional) levels. The methods are implemented in a case study in the north of Portugal, where this is a very opportune issue.
Relatório de estágio realizado na Escola Básica Rainha Dona Leonor de Lencastre em São Marcos
O presente relatório refere-se ao estágio pedagógico realizado na Escola Básica Rainha Dona Leonor de Lencastre, em são Marcos, e contempla as ações desenvolvidas ao longo do ano letivo. O estágio pedagógico foi uma etapa decisiva da nossa formação académica, onde foi possível estar em contato com o contexto escolar e todos os seus intervenientes, pôr em prática os conhecimentos adquiridos na nossa formação inicial através da intervenção pedagógica, bem como permitiu traçar objetivos profissionais e pessoais, criando estratégias para os atingir. O relatório foi realizado numa lógica sequencial das tarefas ocorridas ao longo do estágio, em que primeiro contextualizo as características próprias da escola que eu encontrei no início do ano letivo, de seguida apresenta a forma como lidei com as diferentes tarefas e funções que me foram incumbidas, terminando com uma reflexão sobre o conjunto de aprendizagens que fui adquirindo. A realização do relatório de estágio teve como intuito descrever os acontecimentos ocorridos ao longo do ano, acompanhando sempre esta mesma descrição com uma análise reflexiva da prática desenvolvida.The present Internship report is based on the pedagogical practicum carried out at the Primary School Rainha Dona Leonor de Lencastre in São Marcos, with the class 8.º and contemplates the actions throughout the school year. The pedagogic practicum was decisive for our academic formation, where it was possible to be in contact with the school context and all its participants, to put into practice the knowledge acquired in our initial formation through the pedagogical intervention, as well as allowing us to set personal and professional goals, creating strategies to achieve them. The report was divided into 3 parts: 1st part contextualizes the characteristics of the school, part 2 presents how I dealt with the different tasks and functions entrusted to me and finally a reflection was made on the set of learning that I acquired. The main purpose of the internship report was to describe the events that occurred during the year, always accompanying this same description with a reflexive analysis of the developed practice
Framework de Tomada de Decisão para Last-Mile Sustentável
The e-commerce growth, propelled by factors like globalization, urbanization, or the COVID-19 pandemic, has been raising the demand for logistic activities. This affects the entire supply chain, especially the last-mile, as it is considered the most ineffective part of the supply chain and a source of negative externalities. Although various solutions promise to alleviate these problems, understanding them and selecting the best has proven to be difficult due to conflicting criteria, multiple perspectives, and trade-offs. The vicissitudes of complex and sensitive urban contexts like historic centers also contribute to this difficulty. This work contributes an integrated framework that may assist the involved stakeholders in decision-making. To this end, this work is based on a three-part methodology. The extensive systematic literature review developed provided an integrated overview of this fragmented research area. This review confirmed the multidisciplinary nature of the topic, as there is an increasing number of studies conducted under very different perspectives. Furthermore, it was found that the economic dimension is the most considered; the most polluting countries contributed little to the research; and the solutions involve trade-offs. The literature review supported the definition of the hierarchical model that structures last-mile operations in historic centers. This model was evaluated by interviewing a group of experts. After integrating the experts’ feedback, the model was quantified by the same experts according to an AHP-TOPSIS approach. This quantification had as a case study the historic center of Porto, Portugal. The experts considered the three sustainability dimensions identically important. Air pollution was the most valued sub-criterion whereas Visual pollution was the least. All last-mile solutions considered in the model achieved similar results, therefore suggesting a combined distribution strategy. Nevertheless, the use of parcel lockers is the most favorable solution and seems adequate in Porto’s historic center.O crescimento do e-commerce, impulsionado por fatores como a globalização, a urbanização ou a pandemia de COVID-19, tem aumentado a procura por atividades logísticas. Isto afeta toda a cadeia de abastecimento, principalmente a última-milha, por ser considerada a parte mais ineficaz da cadeia de abastecimento e uma fonte de externalidades negativas. Embora existam várias soluções que prometem aliviar estes problemas, entendêlas e selecionar a melhor tem se provado difícil devido a critérios conflituosos, múltiplas perspetivas e trade-offs. As vicissitudes de contextos urbanos complexos e sensíveis como os centros históricos também contribuem para essa dificuldade. Este trabalho contribui um framework integrado que pode auxiliar os stakeholders envolvidos na tomada de decisão. Para este fim, este trabalho é baseado numa metodologia composta por três partes. A extensa revisão sistemática da literatura desenvolvida forneceu uma visão integrada desta área de investigação fragmentada. Esta revisão confirmou o caráter multidisciplinar do tema, pois há um número crescente de estudos conduzidos sob perspetivas muito diferentes. Além disso, verificou-se que a dimensão económica é a mais considerada; os países mais poluentes contribuíram pouco para a pesquisa; e as soluções envolvem trade-offs. A revisão da literatura suportou a definição do modelo hierárquico que estrutura as operações de última-milha em centros históricos. Este modelo foi avaliado entrevistando um grupo de experts. Após a integração do feedback dos experts, o modelo foi quantificado pelos mesmos de acordo com uma abordagem AHP-TOPSIS. Esta quantificação teve como caso de estudo o centro histórico do Porto, Portugal. Os experts consideraram as três dimensões da sustentabilidade identicamente importantes. O subcritério relativo à poluição atmosférica foi o mais valorizado, enquanto o menos foi o relativo à poluição visual. Todas as soluções de últimamilha consideradas no modelo alcançaram resultados semelhantes, sugerindo uma estratégia de distribuição combinada. No entanto, o uso de parcel lockers é a solução mais favorável e é aparentemente adequada para o centro histórico do Porto
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