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1.
J Environ Manage ; 359: 120864, 2024 May.
Article in English | MEDLINE | ID: mdl-38714029

ABSTRACT

Deforestation rates in the Amazon have markedly increased in the last few years, affecting non-protected and protected areas (PAs). Brazil is a hotspot of Protected Area Downgrading, Downsizing, and Degazettement (PADDD) events, with most events associated with infrastructure projects. Despite the threats dams impose on PAs, there is a knowledge gap in assessing deforestation in PAs around large dams in the Amazon. This study investigates how deforestation affects Biodiversity Protection Areas (BioPAs) and Indigenous Lands around the Jirau and Santo Antônio (JSA) dams (Madeira River, Rondônia) and Belo Monte dam (Xingu River, Pará) in the Brazilian Amazon. We compared clear-cutting between PAs and control areas and the annual rates of forest change between pre-dam and post-dam periods. We discussed deforestation-related factors (e.g., PADDD events and the presence of management plans or councils). Our results show an increase in deforestation after the operation of the dams when environmental control from licensing agencies decreases and other political and economic factors are in practice. Indigenous Lands experienced a significant increase in deforestation around the Belo Monte dam, which is associated with the demarcation process and land conflicts. Surrounding the JSA dams, sustainable use BioPAs showed high deforestation rates, and 27 PADDD events were reported, four directly related to dams. In addition to dams, deforestation was associated with the crisis of Brazilian democracy and the weakening of environmental policies. In conclusion, the weak environmental control from environmental licensing agencies during dam operation and PADDD events have contributed to increased deforestation rates and additional stresses in the Amazon.


Subject(s)
Biodiversity , Conservation of Natural Resources , Brazil , Rivers , Forests
2.
Article in English | MEDLINE | ID: mdl-38397646

ABSTRACT

Within the 2030 Sustainable Development Agenda, large hydropower dams are positioned as a sustainable energy source, notwithstanding their adverse impacts on societies and ecosystems. This study contributed to ongoing discussions about the persistence of critical social issues, even after the investments of large amounts of resources in areas impacted by the construction of large hydropower dams. Our study focused on food insecurity and evaluated this issue in the city of Altamira in the Brazilian Amazon, which has been profoundly socially and economically impacted by the construction, between 2011 and 2015, of Brazil's second-largest dam, namely, Belo Monte. A survey in Altamira city featured a 500-household random sample. Structural equation modeling showed conditioning factors of 60% of the population experiencing varying food insecurity degrees. Poverty, female-led households, lower education, youth, and unemployment were strongly linked to higher food insecurity. Crowded, officially impacted, and resettled households also faced heightened food insecurity. Our findings underscore the food insecurity conditions in the region impacted by the Belo Monte dam, emphasizing the need to take into account this crucial issue while planning and implementing hydropower dams.


Subject(s)
Ecosystem , Poverty , Adolescent , Humans , Female , Brazil , Cities , Food Insecurity , Food Supply
3.
Sci Total Environ ; 904: 166681, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-37673258

ABSTRACT

Climate change mitigation and biodiversity conservation are two major environmental actions that need to be effectively performed this century, alongside ensuring food supply for a growing global human population. These three issues are highly interlinked through land management systems. Thus, major global food production regions located in biodiversity hotpots and with potential for carbon sequestration face trade-offs between these valuable land-based ecosystem services. The state of Mato Grosso in Brazil is one such region, where private lands that have been illegally used for agriculture could be restored to natural vegetation - with potential benefits for climate change mitigation and biodiversity conservation, although with potentially negative effects on food production. To address this challenge, in this study we used a multicriteria nexus modeling approach that considers carbon stocks, priority areas for biodiversity conservation, and the opportunity for food production, to develop scenarios of land allocation that aim to balance the benefits and drawbacks of ecosystem restoration. Results show that forcing landowners to restore their individual lands compromises the potential for a "green land market" throughout the Amazon biome in which private landowners with lower food production capacities (e.g., less connected to markets and infrastructure) would benefit from restoration programs that compensate them for the inclusion of environmental restoration among their economic activities, instead of taking large economic risks to produce more food. We additionally highlight that strategic ecosystem restoration can achieve higher gains in biodiversity and carbon with lower costs of restoration actions and with minimal impacts on agriculture. Analyses like ours demonstrate how scenarios of land allocation that simultaneously address climate mitigation and biodiversity conservation through ecosystem restoration, while also minimizing possible impacts on food production, can be sought to move the world towards a sustainable future.


Subject(s)
Climate Change , Ecosystem , Humans , Brazil , Conservation of Natural Resources/methods , Biodiversity , Agriculture/methods , Carbon
4.
Sci Rep ; 13(1): 11254, 2023 07 12.
Article in English | MEDLINE | ID: mdl-37438427

ABSTRACT

Over the last few years, understanding of the effects of increasingly interconnected global flows of agricultural commodities on coupled human and natural systems has significantly improved. However, many important factors in environmental change that are influenced by these commodity flows are still not well understood. Here, we present an empirical spatial modelling approach to assess how changes in forest cover are influenced by trade destination. Using data for soybean-producing municipalities in the state of Mato Grosso, Brazil, between 2004 and 2017, we evaluated the relationships between forest cover change and the annual soybean trade destination. Results show that although most of the soybean produced in Mato Grosso during the study period (60%) was destined for international markets, municipalities with greater and more consistent soybean production not destined for international markets during the study period were more strongly associated with deforestation. In these municipalities, soybean production was also significantly correlated with cattle and pasture expansion. These results have important implications for the sustainable management of natural resources in the face of an increasingly interconnected world, while also helping to identify the most suitable locations for implementing policies to reduce deforestation risks.


Subject(s)
Conservation of Natural Resources , Glycine max , Humans , Animals , Cattle , Agriculture , Brazil , Forests
5.
PLoS One ; 18(7): e0284760, 2023.
Article in English | MEDLINE | ID: mdl-37450477

ABSTRACT

Large hydropower projects continue to be built in developing nations, despite their known negative impacts. Large-scale energy projects strain local infrastructure and reduce access to infrastructure for households that live near them. Here we investigate the link between large-scale hydropower projects and stress. Our results suggest that these projects create stress through two mechanisms: strains on community resources and through the process of displacement. We also ask how compensation and resettlement programs condition these relationships. Using data from the Madeira river basin in the Brazilian Amazon, we find that hydropower projects increase stress by reducing access to energy, water, sanitation and land. Compensation provided was not sufficient to moderate this effect.


Subject(s)
Rivers , Water , Brazil , Sanitation
6.
J Environ Manage ; 336: 117240, 2023 Jun 15.
Article in English | MEDLINE | ID: mdl-36870321

ABSTRACT

Understanding social and environmental impacts and household adaptation strategies in the face of expansions in energy infrastructure projects is essential to inform mitigation and interventions programs that promote well-being. Here we conducted surveys in seven communities distributed across varying degrees of proximity to a hydropower dam complex in the Brazilian Amazon along about 250 km of the floodplain of the Madeira River. Based on interviews with 154 fishers from these communities, we examine how fishers perceived changes in fisheries yields, changes in the composition of fish species, and whether and how adaptation strategies had evolved 8-9 years after the dams' construction. Most respondents (91%) indicated declines in yields after the dams for both upstream and downstream zones. Multivariate analyses revealed statistically significant differences in the composition of species yields in pre-and post-dam periods for all communities and in both upstream and downstream zones (p < 0.001). The composition of yields diversified after the dams, with an apparent decline in yields of species of greatest market value (e.g., catfishes Brachyplatystoma spp., Pseudoplatystoma spp., and jatuarana Brycon spp.), and increases in yields of a set of other smaller bodied and faster growing species (e.g., 'branquinhas' Psectrogaster spp., Potamohinna spp., and sardines Triportheus spp.). Both downstream and upstream fishers indicated that fishing profits decreased since the dams' construction (76.8% and 67.9%, respectively). To cope with these changes, the majority of both upstream and downstream fishers (>70%) stated they have had to devote more time to fishing after the dams were built. The time fishers spend traveling to fishing locations also increased for upstream communities (77.1%), but not for downstream communities. Thirty-four percent of the interviewees changed the gear they use to fish after the dams construction, with twice as many mentioning uses of non-selective gear, such as gillnets, and declining use of traditional fishing gears such as castnets and a trap ("covi"). Fish consumption overall decreased: fish was consumed 'everyday' before the dams, but 1-2 times per week or rarely after the dams were built. Although the species that declined were those of high economic value, 53% of fishers stated fish prices have increased overall after the dams. These results shed light on the potential challenges faced by fishers and which adaptation strategies they have evolved to maintain livelihoods since the construction of the dams.


Subject(s)
Acclimatization , Rural Population , Humans , Animals , Rivers , Fisheries , Brazil , Fishes
7.
PLOS Glob Public Health ; 3(3): e0001683, 2023.
Article in English | MEDLINE | ID: mdl-36963101

ABSTRACT

During the first two decades of the 21st century, Brazil carried out massive public investments on infrastructure projects, such as large hydropower dams, with potential impact on population health. Here we characterize local malaria transmission and its potential spread during the construction of three large hydropower dams in the Brazilian Amazon. We focus on Porto Velho (PVH), in Rondônia state, where the Santo Antônio and Jirau dams were built (2008-2013), and Altamira region (ATM), in Pará state, where the construction of the Belo Monte dam took place (2011-2016). Analyzed data cover 4 years before, 6 years during, and 4 years after each dam construction. In total, we utilized malaria case notifications entered into the electronic malaria notification system of the Ministry of Health of Brazil between January 2004 and December 2020 (n = 39,977,167 malaria notifications). First, we used Interrupted Time-Series Analysis (ITSA) to assess temporal changes in malaria notifications in the study sites. Then, we conducted a space-time cluster analysis to investigate the potential of malaria spread from the study sites (sources) to elsewhere (sinks). Finally, we present the sociodemographic characteristics of exported cases over time using multivariate logistic regressions. Our results show that there was no upsurge in malaria cases in the study sites and exported cases did not trigger outbreaks in other localities. Exported malaria infections originating from PVH and ATM were typically found in working age literate males involved in mining, farming or traveling. We suggest that efficient control measures, such as ensuring timely diagnosis and treatment; fostering integrated vector control; promoting health education; and prevention, detection and containment of outbreaks, if properly implemented and sustained, may prevent local and introduced malaria outbreaks during and after hydropower dam construction in the Amazon.

8.
Materials (Basel) ; 10(7)2017 Jul 01.
Article in English | MEDLINE | ID: mdl-28773096

ABSTRACT

Research and development of lead-free piezoelectric materials are still the hottest topics in the field of piezoelectricity. One of the most promising lead-free family of compounds to replace lead zirconate-titanate for actuators is that of Bi0.50Na0.50TiO3 (BNT) based solid solutions. The pseudo-binary (1 - x)Bi0.50Na0.50TiO3-xBa1 - yCayTiO3 system has been proposed for high temperature capacitors and not yet fully explored as piezoelectric material. In this work, the solid solution with x = 0.06 and y = 0.10 was obtained by two different synthesis routes: solid state and Pechini, aiming at using reduced temperatures, both in synthesis (<800 °C) and sintering (<1150 °C), while maintaining appropriated piezoelectric performance. Crystal structure, ceramic grain size, and morphology depend on the synthesis route and were analyzed by X-ray diffraction, together with scanning and transmission electron microscopy. The effects of processing and ceramic microstructure on the structural, dielectric, ferroelectric, and piezoelectric properties were discussed in terms of a shift of the Morphotropic Phase Boundary, chemically induced by the synthesis route.

9.
Materials (Basel) ; 9(1)2016 Jan 02.
Article in English | MEDLINE | ID: mdl-28787822

ABSTRACT

The search for electroceramic materials with enhanced ferro-pyro-piezoelectric properties and revealing the perovskite type structure has been the objective of a significant number of manuscripts reported in the literature. This has been usually carried out by proposing the synthesis and processing of new compounds and solid solution series. In this work, several methods to obtain ferro-pyro-piezoelectric families of materials featuring the well-known ABO3 perovskite structure (or related) such as BaTiO3, Ba1-xCaxTi1-yZryO3, (Bi0.5Na0.5)TiO3, (K0.5Na0.5)NbO3 and their solid solutions with different cations either in the A or B positions, are presented. For this kind of materials, the challenge for obtaining a single phase compound with a specific grain size and morphology and, most importantly, with the adequate stoichiometry, will also be discussed. The results reviewed herein will be discussed in terms of the tendency of working with softer conditions, i.e., lower temperature and shorter reaction times, also referred to as soft-chemistry.

10.
GIsci Remote Sens ; 50(2): 172-183, 2013.
Article in English | MEDLINE | ID: mdl-24151451

ABSTRACT

Impervious surface area (ISA) is an important parameter related to environmental change and socioeconomic conditions, and has been given increasing attention in the past two decades. However, mapping ISA using remote sensing data is still a challenge due to the variety and complexity of materials comprising ISA and the limitations of remote sensing data spectral and spatial resolution. This paper examines ISA mapping with Landsat Thematic Mapper (TM) images in urban and urban-rural landscapes in the Brazilian Amazon. A fractional-based method and a per-pixel based method were used to map ISA distribution, and their results were evaluated with QuickBird images based on the 2010 Brazilian census at the sector scale of analysis for examining the mapping performance. This research showed that the fraction-based method improved the ISA estimation, especially in urban-rural frontiers and in a landscape with a small urban extent. Large errors were mainly located at the sites having ISA proportions of 0.2-0.4 in a census sector. Calibration with high spatial resolution data is valuable for improving Landsat-based ISA estimates.

11.
Int J Remote Sens ; 34(16): 5953-5978, 2013.
Article in English | MEDLINE | ID: mdl-24127130

ABSTRACT

This paper provides a comparative analysis of land use and land cover (LULC) changes among three study areas with different biophysical environments in the Brazilian Amazon at multiple scales, from per-pixel, polygon, census sector, to study area. Landsat images acquired in the years of 1990/1991, 1999/2000, and 2008/2010 were used to examine LULC change trajectories with the post-classification comparison approach. A classification system composed of six classes - forest, savanna, other-vegetation (secondary succession and plantations), agro-pasture, impervious surface, and water, was designed for this study. A hierarchical-based classification method was used to classify Landsat images into thematic maps. This research shows different spatiotemporal change patterns, composition and rates among the three study areas and indicates the importance of analyzing LULC change at multiple scales. The LULC change analysis over time for entire study areas provides an overall picture of change trends, but detailed change trajectories and their spatial distributions can be better examined at a per-pixel scale. The LULC change at the polygon scale provides the information of the changes in patch sizes over time, while the LULC change at census sector scale gives new insights on how human-induced activities (e.g., urban expansion, roads, and land use history) affect LULC change patterns and rates. This research indicates the necessity to implement change detection at multiple scales for better understanding the mechanisms of LULC change patterns and rates.

12.
Pesqui Agropecu Bras ; 47(9)2012 Sep.
Article in English | MEDLINE | ID: mdl-24353353

ABSTRACT

Land use/cover classification is one of the most important applications in remote sensing. However, mapping accurate land use/cover spatial distribution is a challenge, particularly in moist tropical regions, due to the complex biophysical environment and limitations of remote sensing data per se. This paper reviews experiments related to land use/cover classification in the Brazilian Amazon for a decade. Through comprehensive analysis of the classification results, it is concluded that spatial information inherent in remote sensing data plays an essential role in improving land use/cover classification. Incorporation of suitable textural images into multispectral bands and use of segmentation-based method are valuable ways to improve land use/cover classification, especially for high spatial resolution images. Data fusion of multi-resolution images within optical sensor data is vital for visual interpretation, but may not improve classification performance. In contrast, integration of optical and radar data did improve classification performance when the proper data fusion method was used. Of the classification algorithms available, the maximum likelihood classifier is still an important method for providing reasonably good accuracy, but nonparametric algorithms, such as classification tree analysis, has the potential to provide better results. However, they often require more time to achieve parametric optimization. Proper use of hierarchical-based methods is fundamental for developing accurate land use/cover classification, mainly from historical remotely sensed data.

13.
Int J Remote Sens ; 32(23): 8207-8230, 2011.
Article in English | MEDLINE | ID: mdl-22368311

ABSTRACT

This research aims to improve land-cover classification accuracy in a moist tropical region in Brazil by examining the use of different remote sensing-derived variables and classification algorithms. Different scenarios based on Landsat Thematic Mapper (TM) spectral data and derived vegetation indices and textural images, and different classification algorithms - maximum likelihood classification (MLC), artificial neural network (ANN), classification tree analysis (CTA), and object-based classification (OBC), were explored. The results indicated that a combination of vegetation indices as extra bands into Landsat TM multispectral bands did not improve the overall classification performance, but the combination of textural images was valuable for improving vegetation classification accuracy. In particular, the combination of both vegetation indices and textural images into TM multispectral bands improved overall classification accuracy by 5.6% and kappa coefficient by 6.25%. Comparison of the different classification algorithms indicated that CTA and ANN have poor classification performance in this research, but OBC improved primary forest and pasture classification accuracies. This research indicates that use of textural images or use of OBC are especially valuable for improving the vegetation classes such as upland and liana forest classes having complex stand structures and having relatively large patch sizes.

14.
São Paulo; Editora Senac; 2011. 307 p. ilus, graf.
Monography in Portuguese | LILACS | ID: lil-691644

ABSTRACT

Diante da crescente evidência das mudanças climáticas, da perda da biodiversidade, do acelerado desflorestamento nos trópicos e da crise iminente de disponibilidade de água potável, a pesquisa ambiental demanda melhor entendimento da complexa interação homem-ambiente. Tem ocorrido um rápido crescimento do desenvolvimento da pesquisa a respeito das dimensões humanas das mudanças ambientais. Moran oferece uma síntese dessa nova iniciativa interdisciplinar, fornecendo uma base para que as pessoas possam lidar com as necessidades urgentes desses processos em escala global.


Subject(s)
Humans , Climate Change , Ecosystem , Environment , Human Ecology
15.
Philos Trans R Soc Lond B Biol Sci ; 363(1498): 1803-9, 2008 May 27.
Article in English | MEDLINE | ID: mdl-18267908

ABSTRACT

This paper argues for a twofold perspective on human adaptation to climate change in the Amazon. First, we need to understand the processes that mediate perceptions of environmental change and the behavioural responses at the levels of the individual and the local population. Second, we should take into account the process of production and dissemination of global and national climate information and models to regional and local populations, especially small farmers. We discuss the sociocultural and environmental diversity of small farmers in the Amazon and their susceptibility to climate change associated with drought, flooding and accidental fire. Using survey, ethnographic and archival data from study areas in the state of Pará, we discuss farmers' sources of knowledge and long-term memory of climatic events, drought and accidental fire; their sources of climate information; their responses to drought and fire events and the impact of changing rainfall patterns on land use. We highlight the challenges of adaptation to climate change created by the influence of migration and family turnover on collective action and memory, the mismatch of scales used to monitor and disseminate climate data and the lack of extension services to translate large-scale forecasts to local needs. We found that for most farmers, memories of extended drought tend to decrease significantly after 3 years. Over 50% of the farmers interviewed in 2002 did not remember as significant the El Niño Southern Oscillation (ENSO) drought of 1997/1998. This helps explain why approximately 40% of the farmers have not changed their land-use behaviours in the face of the strongest ENSO event of the twentieth century.


Subject(s)
Agriculture/economics , Conservation of Natural Resources/economics , Greenhouse Effect , Adaptation, Physiological , Brazil , Data Collection , Disasters , Family Characteristics , Humans , Rural Population , Socioeconomic Factors , Surveys and Questionnaires
16.
Photogramm Eng Remote Sensing ; 74(3): 311-321, 2008.
Article in English | MEDLINE | ID: mdl-19789716

ABSTRACT

Complex forest structure and abundant tree species in the moist tropical regions often cause difficulties in classifying vegetation classes with remotely sensed data. This paper explores improvement in vegetation classification accuracies through a comparative study of different image combinations based on the integration of Landsat Thematic Mapper (TM) and SPOT High Resolution Geometric (HRG) instrument data, as well as the combination of spectral signatures and textures. A maximum likelihood classifier was used to classify the different image combinations into thematic maps. This research indicated that data fusion based on HRG multispectral and panchromatic data slightly improved vegetation classification accuracies: a 3.1 to 4.6 percent increase in the kappa coefficient compared with the classification results based on original HRG or TM multispectral images. A combination of HRG spectral signatures and two textural images improved the kappa coefficient by 6.3 percent compared with pure HRG multispectral images. The textural images based on entropy or second-moment texture measures with a window size of 9 pixels × 9 pixels played an important role in improving vegetation classification accuracy. Overall, optical remote-sensing data are still insufficient for accurate vegetation classifications in the Amazon basin.

17.
Photogramm Eng Remote Sensing ; 74(4): 421-430, 2008.
Article in English | MEDLINE | ID: mdl-19789721

ABSTRACT

Traditional change detection approaches have been proven to be difficult in detecting vegetation changes in the moist tropical regions with multitemporal images. This paper explores the integration of Landsat Thematic Mapper (TM) and SPOT High Resolution Geometric (HRG) instrument data for vegetation change detection in the Brazilian Amazon. A principal component analysis was used to integrate TM and HRG panchromatic data. Vegetation change/non-change was detected with the image differencing approach based on the TM and HRG fused image and the corresponding TM image. A rule-based approach was used to classify the TM and HRG multispectral images into thematic maps with three coarse land-cover classes: forest, non-forest vegetation, and non-vegetation lands. A hybrid approach combining image differencing and post-classification comparison was used to detect vegetation change trajectories. This research indicates promising vegetation change techniques, especially for vegetation gain and loss, even if very limited reference data are available.

18.
Science ; 317(5844): 1513-6, 2007 Sep 14.
Article in English | MEDLINE | ID: mdl-17872436

ABSTRACT

Integrated studies of coupled human and natural systems reveal new and complex patterns and processes not evident when studied by social or natural scientists separately. Synthesis of six case studies from around the world shows that couplings between human and natural systems vary across space, time, and organizational units. They also exhibit nonlinear dynamics with thresholds, reciprocal feedback loops, time lags, resilience, heterogeneity, and surprises. Furthermore, past couplings have legacy effects on present conditions and future possibilities.


Subject(s)
Conservation of Natural Resources , Ecosystem , Environment , Human Activities , Animals , Biodiversity , Brazil , China , Ecology , Humans , Socioeconomic Factors , Sociology , Sweden , United States
19.
Rev. colomb. cardiol ; 14(3)mayo-jun. 2007. tab, graf
Article in Spanish | LILACS | ID: lil-469034

ABSTRACT

Introducción y objetivos: la miocardiopatía hipertrófica es una enfermedad de origen genético con prevalencia de 1 porciento al 2 porciento. La mitad de los pacientes fallecen por muerte súbita cardiaca, la mayoría por arritmias ventriculares. Todavía no está claro a qué pacientes se les debe implantar un desfibrilador automático. El objetivo de este trabajo es describir una serie de pacientes con implante, los criterios empleados y los resultados obtenidos, así como analizar los predictores de terapia apropiada por el desfibrilador.Métodos: se incluyeron 20 pacientes que recibieron un desfibrilador de tercera generación. En todos se realizó estudio electrofisiológico y seguimiento prospectivo con registro de eventos. En 18 (90 porciento) se hizo estudio genético.


Introduction and objectives: hypertrophic myocardiopathy is a genetic entity with 1% to 2% prevalence. Half patients die of sudden cardiac death, most due to ventricular arrhythmias. There is still no clarity with regard to the patients to whom an automatic defibrillator has to be implanted. The objective of this work is to describe a series of patients with implant, the criteria used and the results obtained, as well as to analyze the predictors of appropriate therapy with the defibrillator. Methods: 20 patients that received a third generation defibrillator were included. Electrophysiological study and prospective follow-up with register of events was performed in all. Genetic study was done in 18 (90%). Results: 55% were men with mean age 40 (11-78) years. Six (30%) received implant for secondary prevention and 14 (70%) for primary prevention; the last ones because of several risk factors. A sustained arrhythmia was induced in 15 (75%) and in 3 (15%) monomorphic sustained ventricular tachycardia. At 22 months of follow-up, 4 (20%) underwent appropriate therapy and 2 (10%) died. Clinical monomorphic ventricular tachycardia (p=0.03) and the induced one (p<0.01) were significant therapy predictors. In 10 (56%) a mutation was identified; in 8 (44%) in the b-myosin gene. Conclusions: monomorphic sustained clinical ventricular tachycardia and the induced one were predictors of the appropriate defibrillator therapy in this series. The stratification based on the risk factors addition is actually a good option for primary prevention. Mutations in the heavy b-myosin chain are also the most frequent in our population.


Subject(s)
Cardiomyopathy, Hypertrophic , Electrophysiologic Techniques, Cardiac , Tachycardia, Ventricular
20.
Acta amaz ; Acta amaz;35(2): 239-247, abr.-jun. 2005. ilus, tab, graf
Article in Portuguese | LILACS | ID: lil-413339

ABSTRACT

O entendimento das mudanças em paisagens amazônicas depende de documentação das alterações na cobertura da terra. Este artigo parte de resultados do Experimento de Larga Escala de Biosfera-Atmosfera na Amazônia (LBA) relativos ao tema para focalizar um estudo transversal que analisa as dimensões sociais e biofísicas dessas transformações. As áreas de estudo representam um gradiente de fertilidade de solos e inclui distintos mosaicos de paisagens, desde o estuário Amazônico e a Região Bragantina até o nordeste de Rondônia. Areas de assentamento rural são enfatizadas, devido a sua relevância social e a seus impactos sobre a cobertura das terras em escala local e regional. Para exemplificar o potencial destes estudos, apresentamos resultados comparativos para Machadinho d'Oeste e Vale do Anari, RO. A análise multitemporal utilizou imagens do satélite Landsat e levantamentos de campo. Proprietários, seringueiros, madeireiros e outros atores locais foram entrevistados sobre seus sistemas de produção e a história de uso das terras. O cálculo de métricas espaciais embasou nossas conclusões. Os resultados indicam que o desenho do assentamento e aspectos institucionais têm um papel importante no processo de alteração da paisagem. A combinação de lotes privados com reservas comuns, manejadas por populações locais, pode produzir efeitos positivos na manutenção de maiores manchas de floresta. A metodologia utilizada oferece potenciais de integração, análise e monitoramento do uso e cobertura das terras na Amazônia, visando fornecer subsídios a políticas que valorizem as dimensões sociais e ambientais do desenvolvimento da região.


Subject(s)
Amazonian Ecosystem
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