Browsing by Author "Xavier, António"
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- An integrated decision support system for the Mediterranean forestsPublication . Costa Freitas, M. B.; Xavier, António; Fragoso, R.Mediterranean forests contain a relevant biological diversity and are relevant for local economy. However, they are subject to various risks, particularly the risk of forest fires. This turns the critical decisions of forest managers, affecting both the long-term future of the forest and daily activities, to be difficult. To simulate decisions, and help managers and policy makers, a decision support system, which integrates the biological, environmental and economic management perspectives of agricultural and forest areas, was developed and considers the activities existing in the territory. The decision support system considers the characteristics of the biophysical units that comprise the territorial study area, production technologies and conservation of agro-forestry goods and preferences of managers or stakeholders. The proposed approach was applied in a pilot Forest Intervention Zone (FIZ) located within the Algarve region inner land. The results show that the decision support system proposed is an important tool for managing the territory and for implementing the manager's decisions. (C) 2015 Elsevier Ltd. All rights reserved.
- Analysing the recent dynamics of agricultural sustainability in Portugal using a compromise programming approachPublication . Xavier, António; Costa Freitas, M. B.; Fragoso, Rui; Rosário, Maria do SocorroSociety recognises the importance of agriculture to supply goods, which are essential for human survival and well-being. Sustainable agriculture is an important goal since resources need to be preserved for future generations. The recent agricultural policy orientations towards environmental concerns have also had consequences for Portuguese agriculture. The information provided by the 2019 Agricultural Census offers an opportunity to analyse the recent dynamics and establish rankings of municipalities related to agricultural sustainability. Sustainability in agriculture can be studied using different types of indicators, but its quantification and aggregation into an index is still difficult. This paper proposes an approach based on compromise programming to analyse sustainability considering the dynamics between the 2009 and 2019 Agricultural Census. This approach has three main steps: in the first one, the indicators are selected and a HJ-Biplot and Cluster analysis are carried out to identify groups of municipalities and general dynamics; in the second step, the weights of indicators are defined, and a novel compromise programming model is implemented to define the rankings of sustainability for each year; finally, in the third step, the spatial dynamics of the sustainability rankings are analysed and classified into the clusters of municipalities previously created. The analysis was implemented using data from the 308 Portuguese municipalities for 12 individual indicators encompassing the several dimensions of sustainability. The results were promising since the approach allowed for the identification of the main dynamics and tendencies regarding sustainability.
- Combined disaggregation of agricultural land uses, livestock numbers and crops' production: an entropy approachPublication . Xavier, António; Freitas, Maria de Belém; De Sousa Fragoso, R. M.This paper presents several combined agricultural data disaggregation models in order to recover the farms' land uses, the livestock numbers and main crops' productions. The proposed approach estimates incomplete information at disaggregated level through entropy, using an information prior, and generating information for a combined calculation use of data in the estimation of other variables. The models were applied to the region of Algarve, to some rural pilot areas (Salir-Ameixial-Cachopo and Alcoutim) for livestock data, since this data in some Algarve's inland areas is needed for a European forest fire prevention project, and to the agrarian zones in a more complex framework. The results are promising. They were validated, in cross reference to real data, having proven to be valid and reliable. The total error was small and a considerable level of information heterogeneity was recovered. The total error was about 27,9% for the counties' land uses and 21% for the agrarian zones, and for the livestock it was also acceptable. The level of heterogeneity recovered was always higher than 50%, revealing some improvements regarding previous studies.
- A composite indicator to measure sustainable water use in Portugal: a compromise programming approachPublication . Costa Freitas, M. B.; Xavier, António; Fragoso, Rui; Antunes, CarlaClean water is an important resource for maintaining human life, economic activities, and ecosystems' survival. Nevertheless, its irregular distribution and occasional scarcity lead to the need to promote its sustainable use. To assess the current situation and the dynamics of sustainable water use, it is crucial to identify the main factors affecting it and to propose monitoring indicators. This paper develops an approach based on compromise programming to analyse water use sustainability at the municipal level, with a methodology that comprise a framework designed in five steps: 1 - indicators' choice; 2 - indicators's weights; 3 - definition of sustainability rankings with the application of a compromise programming approach; 4- application of a GIS analysis; 5 - identification of the main factors affecting sustainable water use. As a first result, the consensus weights of the chosen indicators were defined, indicating that the most important internal factors affecting sustainable water use are safe water, the percentage of housing served by water supply and water distributed by inhabitant. Then sustainability rankings at the municipality level were defined considering these factors. Finally, it was possible to conclude that tourism activity, income level, and young age population have a significant negative effect on sustainable water use, and municipal revenue has a positive effect. Irrigated farming shows a non-significant negative effect on sustainable water use. Population density, elderly population and education level did not show the expected effects on sustainable water use.
- A compromise programming approach for assessing territorial biophysical suitability: a Case StudyPublication . Xavier, António; Ferreira da Silva da Costa Freitas, Maria de Belém; Rolo Antunes, Carla MariaLand-use fragmentation is an important issue for land management and rural development. For the last few decades, the relationship between mankind and land has become more dynamic though the traditional cadastral system has been slow in responding to the changing needs of society. Associated with land-use fragmentation, there are different sizes of land parcels with different biophysical characteristics that will dictate different land management decisions, and, in many countries, it is a problem that constitutes a challenge for correct land management. This article proposes a compromise programming approach for determining the biophysical potential of land parcels. This approach was implemented in Loul & eacute; municipality, Portugal, in more than 50,000 parcels. Results were promising since the approach was able to build a ranking of parcels that have different biophysical conditions, proving that this approach is relevant and interesting for land management.
- A desagregação espacial de dados agrícolas: aplicação de uma abordagem baseada na máxima entropia ao concelho de Castelo de VidePublication . Xavier, António; Martins, Maria de Belém; Fragoso, Rui Manuel de SousaThe purpose of this dissertation is to complement the lack of data related to the forest and agricultural occupation and the livestocks in Castelo de Vide. To solve the research problem a model of data disaggregation was developed, taking the utmost of previous information available in earlier studies. The proposed model was based on the ideas of generalized maximum entropy (GME) and minimum generalized crossed entropy (MGCE), in order to obtain a series of disaggregated data related to the forest and agricultural occupation, considering two levels of disaggregation and following two steps: 1) the creation of a basis at the aggregated level (Markov transition matrixes, estimated by the maximum entropy); 2) data disaggregation, based on the previous established basis. The model also involves two application variants: simultaneous disaggregation of data as well as a direct one (to solve the problems that might appear in the previous one and maximize the recovered information). Moreover, a model based on these principles is proposed to the disaggregation of the livestock data. The model is applied to the disaggregation of data in the municipality of Castelo de Vide. The results obtained in the process of direct disaggregation of the forest and agricultural occupation and livestock have shown to be reliable. They have been validated in the year of 1999, submitted to experts? opinions, to other sources of information and compared to the results of other methodologies. The analysis of the results showed that the forest and agricultural occupation of Alto Alentejo and Castelo de Vide after 1999 tend to be more homogeneous, with a strong domain of permanent pastures, and there is a shortage of certain livestocks (sheep and goats). The several CAP changes have had effects in Alto Alentejo and Castelo de Vide, since they have contributed to a larger extensification of the practice of agriculture and to the decline of traditional productions.
- Innovation for Sustainability and NetworkingPublication . Kijkamp, Peter; Pinto, Hugo; Xavier, António; Noronha, Teresa de; Faustino, Chanda; Vaz, Eric; Madureira, Lívia; Gamito, Teresa Maria; Ferreira, Dora; Oliveira, Ivo; Portela, José; Monteiro, Pedro Valadas; Neto, Paulo; Maldonado, Mauricio; Hobeica, Adib; Gomes, Jorge F. S.; Bernardo, Sofia; Noronha, Teresa de; Gomes, Jorge F.S.Throughout human history, innovation has been the main factor in adapting humanity to its settings. On the basis of earlier practice, human creativity allows the finding of new, permanent ways to do things. their applications encourage new spaces, new necessities and new lifestyles. Innovation has been an element of human capacities from its earlier stages, but it has been recognized only recently as a clear device of social and economic change.
- Um modelo bioeconómico para a gestão sustentável das florestas mediterrâneasPublication . Xavier, António; Freitas, Maria de Belém; Fragoso, Rui Manuel de Sousa; Panagopoulos, ThomasAs florestas mediterrâneas contêm uma diversidade vegetal, animal e biológica considerável e são relevantes para a vida das populações locais, contudo estão sujeitas a vários riscos, um dos quais é o risco de incêndios florestais. Para potenciar e valorizar as florestas mediterrâneas e as áreas agrícolas que se situam junto a elas, é necessário uma solução de gestão integrada que as valorize e maximize os benefícios que delas retiramos. Assim, de forma a atingir este objetivo, desenvolveu-se um modelo de programação matemática que integra as perspetivas biológica, ambiental e económica na gestão das áreas agrícolas e florestais, considerando todas as atividades existentes no território. O modelo de gestão integrado considera as características das unidades biofísicas que compõem o território objeto de estudo, as tecnologias de produção, conservação de bens agro-florestais e as preferências dos gestores para delinear uma estratégia eficiente com vista a desenvolver um plano de gestão sustentável da floresta. É um modelo de programação matemática estocástica discreta de equilíbrio estático em que se pretende contribuir para melhorar a situação dos diferentes proprietários, dotando os gestores de instrumentos que lhes permitam tomar decisões fundamentadas e consistentes com os vários fatores de natureza económica, ambiental e social. Para além do modelo de gestão proposto, foram desenvolvidos dois modelos auxiliares são complementares ao modelo de gestão e que permitem o aperfeiçoamento dos resultados: 1) modelo auxiliar de definição de preferências de gestão; 2) modelo de localização que permite fazer a redistribuição dos resultados do plano de gestão para o nível da parcela. A abordagem metodológica proposta foi aplicada numa Zona de Intervenção Florestal (ZIF) piloto situada no interior da Região do Algarve: a ZIF Arade-Alte/ S. B. Messines. Os resultados demonstram que a abordagem metodológica proposta permitiu definir um plano de gestão completo calculando a melhor situação de compromisso para critérios chave na gestão florestal. Complementarmente, foi possível obter resultados com um enorme detalhe nas diferentes parcelas de terrenos, sendo provado que esta abordagem é uma ferramenta útil para o gestor.