Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Sci Total Environ ; 880: 163248, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37023826

RESUMO

Land is a key resource for human activities under growing pressure. Resource criticality assessment methods investigate the extent to which a resource may become a limiting factor according to various dimensions, including geological, economic and geopolitical availability. They have been applied to resources like minerals, fossil fuels, biotic material or water, but none consider land resources, i.e. natural land units providing space and support for human activities. Based on two recognised criticality methods developed by i) the Yale University and ii) the Joint Research Centre of the European Commission, this study aims to develop spatialized land supply risk indexes at country level. The accessibility of raw resources can be quantified and compared using the supply risk index. The specific characteristics of land call for certain adaptations of the criticality approach, and are designed to ensure comparability between resources. The main adaptations include the definition of land stress and the internal land concentration index. Land stress represents the physical availability of land, while internal land concentration relates to the concentration of landowners within a country. Finally, land supply risk indexes are computed for 76 countries, including 24 European countries for which the results of the two criticality methods are compared. Comparison points to divergences in the countries ranking for land accessibility, thus underlining the importance of methodological choices in the construction of the indexes. Data quality is discussed for European countries with the JRC method, and the use of alternative data sources reveals that it may lead to differences in absolute values, although the ranking of countries with low or high land supply risk does not change. Finally, this work covers a gap in criticality methods by including land resources. These resources can be critical for certain countries, and are essential for human activities such as food or energy production.

2.
J Environ Manage ; 268: 110555, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32383662

RESUMO

Brazil's Amazon deforestation is a major global and national environmental concern, and the ability to model and project both its course and the effect of different policy options depends on understanding how this process occurs at present and how it might change in the future. The present paper addresses one key factor in Amazon deforestation: land-tenure concentration in settlements. Brazil's policies for establishing and regulating settlement projects represent critical government decisions shaping the landscape in the 5 × 106 km2 Legal Amazonia region. We used remote-sensing data and information provided by the National Institute for Colonization and Agrarian Reform (INCRA) to evaluate the effect of land-tenure concentration in a settlement project (Projeto de Assentamento) located in a frontier area where cattle-ranching is expanding. We identified the actors and their deforestation patterns in the Matupi settlement in the southern part of Brazil's state of Amazonas. We spatially identified actors who concentrated "lots" (the parcels of land distributed to individual settlers) in 2011 and assessed whether the concentration was done by individual landholders or by "families" (where members merged their lots and the clearing was done together). Deforestation rates (1995-2011) were estimated for each type of actor and the trajectory of deforestation in the settlement (cumulative deforestation to 1994 and annual deforestation 1995-2016) was also analyzed. Concentrators occupied 28% (9653 ha) of the settlement and 29% of the lots (152 lots) analyzed; the numbers of lots concentrated ranged from two to ten. Concentrators of two lots and non-concentrators were the predominant actor types in the settlement. The mean annual clearing per landholding for concentrators of two lots (families: 4.1 ± 2.8 ha (mean ± SD); individuals: 5.1 ± 4.6 ha) was greater than for non-concentrators (1.7 ± 1.2 ha), despite their having similar patterns of small clearings. Concentrators of three or more lots had mean annual clearing per landholding between 6.2 ± 12.2 ha and 23.9 ± 38.7 ha and, the pattern of patches cleared per year >34 ha in area was predominant. The deforestation rate per lot was higher among concentrators as compared to non-concentrators, showing that lot concentration speeds deforestation. Analysis of deforestation patterns helps to better understand the process of lot concentration by spatially identifying the predominant patterns of each type of actor. The approach used in our study could assist authorities in identifying and monitoring land-tenure concentration in settlements. Agrarian-reform policymakers need to monitor this process, since it speeds deforestation in Amazonian settlement projects, as well as undermining the social objectives of the agrarian-reform program.


Assuntos
Conservação dos Recursos Naturais , Florestas , Animais , Brasil , Bovinos , Fatores Socioeconômicos
3.
Acta Amazon ; 41(2): 223-232, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-24639597

RESUMO

The objective of this article is to present Polarization of Agrarian Structure as a single, more complete representation than models emphasizing rural exodus and consolidation of land into large agropastoral enterprises of the dynamics of changing land distribution, land use / cover, and thus the rural milieu of Amazonia. Data were collected in 2003 using social surveys on a sample of 587 lots randomly selected from among 5,086 lots on a cadastral map produced in the 1970s. Georeferencing of current property boundaries in the location of these previously demarcated lots allows us to relate sociodemographic and biophysical variables of the surveyed properties to the changes in boundaries that have occurred since the 1970s. As have other authors in other Amazonian regions, we found concentration of land ownership into larger properties. The approach we took, however, showed that changes in the distribution of land ownership is not limited to the appearance of larger properties, those with 200 ha or more; there also exists substantial division of earlier lots into properties with fewer than five hectares, many without any agropastoral use. These two trends are juxtaposed against the decline in establishments with between five and 200 ha. The variation across groups in land use / land cover and population distribution shows the necessity of developing conceptual models, whether from socioeconomic, demographic or environmental perspectives, look beyond a single group of people or properties.

4.
Acta amaz ; Acta amaz;41(2): 223-232, 2011. mapas, tab, graf
Artigo em Português | LILACS, VETINDEX | ID: lil-586477

RESUMO

O objetivo deste artigo é apresentar a polarização da estrutura fundiária como uma expressão mais completa das dinâmicas fundiárias, do uso-cobertura da terra e, consequentemente, do meio rural na Amazônia do que modelos explicativos que enfatizam o êxodo rural e a consolidação de grandes estabelecimentos agropecuários. Os dados foram coletados em levantamento realizado no entorno de Santarém-PA, em 2003, nos locais de 587 lotes rurais selecionados aleatoriamente por amostragem estratificada de 5.086 lotes existentes em mapas da década de 1970. O georreferenciamento permitiu comparar a estrutura fundiária nos dois momentos e relacionar variáveis sociodemográficas e biofísicas dos estabelecimentos encontrados. Detectou-se concentração fundiária, corroborando o documentado por outros autores em outras porções da Amazônia. No entanto, a perspectiva adotada revela que a variação na estrutura fundiária não se limitou ao aparecimento de estabelecimentos maiores, com 200 hectares ou mais, mas se deu também pela divisão dos lotes originais em estabelecimentos com menos de cinco hectares, muitos das quais sem uso agropecuário, em contrapartida à redução de estabelecimentos entre cinco e 200 ha. As especificidades de cada grupo de estabelecimentos com relação ao uso-cobertura da terra e a distribuição da população chamam a atenção para a necessidade de se buscar modelos explicativos - seja da perspectiva socioeconômica, demográfica ou ambiental - que não se fixem exclusivamente em um único processo, grupo de pessoas ou de estabelecimentos.


The objective of this article is to present Polarization of Agrarian Structure as a single, more complete representation than models emphasizing rural exodus and consolidation of land into large agropastoral enterprises of the dynamics of changing land distribution, land use / cover, and thus the rural milieu of Amazonia. Data were collected in 2003 using social surveys on a sample of 587 lots randomly selected from among 5,086 lots on a cadastral map produced in the 1970s. Georeferencing of current property boundaries in the location of these previously demarcated lots allows us to relate sociodemographic and biophysical variables of the surveyed properties to the changes in boundaries that have occurred since the 1970s. As have other authors in other Amazonian regions, we found concentration of land ownership into larger properties. The approach we took, however, showed that changes in the distribution of land ownership is not limited to the appearance of larger properties, those with 200 ha or more; there also exists substantial division of earlier lots into properties with fewer than five hectares, many without any agropastoral use. These two trends are juxtaposed against the decline in establishments with between five and 200 ha. The variation across groups in land use / land cover and population distribution shows the necessity of developing conceptual models, whether from socioeconomic, demographic or environmental perspectives, look beyond a single group of people or properties.


Assuntos
Ecossistema Amazônico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA