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An essential process in earthworks is projecting effective routes for material allocation. In highway construction, haul road planning is a challenge for practitioners once there are few consolidated methodologies to rationally select existing haul routes or construct new ones. Some authors indicated geographic information system (GIS)-based methods for routing through least-cost algorithms. However, most proposed methodologies overlook the logistics related to allocations, not considering supply–demand relations in their criteria. Consequently, through a case study in Brazil, we present an earthwork optimization system that integrated established mathematical programming techniques for allocation and a GIS-based algorithm for haul road construction. In summary, we formulated a model capable of selecting different routes based on their impact on earthworks logistics cost. Thus, we built several paths between source and demand points utilizing two methods. First, based on recent literature, we used a GIS-based least-cost algorithm using the measuring attractiveness by a categorical-based evaluation technique (MACBETH) as a multicriteria support system incorporating multiple economic and environmental parameters. Second, we built routes based on Euclidian distance between the same source and demand points, analyzing if the savings in operational costs would payoff additional expenses of choosing a shorter route. After applying our methodology to the case study, we observed that the proposed procedure presented a lower budget in a reasonable processing time compared with the original project. Therefore, we inferred that the strategy of proposing path alternatives can be significantly efficient when applied to highways. Based on the results, we also found opportunities for improvement of our GIS step once it generated long paths when the distance between source and demand was short. [ABSTRACT FROM AUTHOR]

Forest road densities which are too high increase production costs, planting area loss, and environmental impacts. To solve this problem and plan an adequate forest road density, it is necessary to analyze and consider the topography, road network-related costs, and the type and number of machines to meet the required wood production. The aim of this study was to determine the current road density (RD), the optimal economic road density (ORD) and operational road density (OD) in flat and sloping site conditions for the full tree harvesting system in Southern Brazil. The RD was determined by the ratio of total road lengthand the total productive area. ORD was determined based on the transport geometry model, considering the minimization of the sum of unit costs of road construction and maintenance, loss of productive area, mitigation of road impacts, and wood extraction. The OD was determined considering the minimum number of extraction machines necessary to meet the annual demand for wood. All forest road densities were lower in flat site conditions than in sloping areas. In both conditions (flat and sloping), RDs (126 and 180 m ha−1, respectively) were higher than ORDs (53 and 65 m ha−1, respectively), which were lower than ODs (92 and 123 m ha−1, respectively). Therefore, OD can be an alternative parameter for managers to use in forest road network planning, mainly in conditions where ORD is not feasible to adopt. [ABSTRACT FROM AUTHOR]

The choice of an incorrect terrain classification might lead to consequences in construction costs, design speed, or even safety. However, the current design criteria for terrain classification may be highly subjective. In Brazil, design guidelines use textual descriptors for three classes, namely level, rolling, and mountainous. This study proposes a fuzzy rule-based classifier to predict terrain classes based on average slope and slope variation. The classifier uses fuzzy logic, which can account for imprecise and vague definitions of the input variables. The classifier was built using topographic variables, i.e. slope variation and average slope, and experts' knowledge. A survey was considered to extract experts' opinions regarding different terrain classes. The classifier provided an accuracy of at least 75%, which suggests that the expert system captured the experts' perceptions of the highway classes. As a result, the proposed system can assist decision-making by providing a more consistent method for terrain classification. [ABSTRACT FROM AUTHOR]

Paracoccidioidomycosis (PCM) is a neglected endemic mycosis in Latin America. Most cases occur in Brazil. It is classified as PCM infection and PCM disease and is subdivided into chronic (adult type) or acute (juvenile type) disease, with the latter being less frequent and more severe. In 2016, we reported an increase in the numbers of patients diagnosed with acute PCM after a highway's construction. We conducted a study at INI-Fiocruz, a reference center for infectious diseases, including endemic mycoses, in Rio de Janeiro, Brazil, aiming to deepen the analysis of this new clinical and epidemiological profile of PCM. The authors developed a retrospective study including 170 patients diagnosed with PCM between 2010 and 2019. There was an increase in the number of atypical and severe forms, starting in 2014. In subsequent years, we detected a higher incidence of adverse outcomes with patients requiring more hospitalizations and an increased mortality rate. We estimate that PCM has become more severe throughout the Rio de Janeiro state, affecting a greater number of young individuals and leading to a greater number of and longer hospitalizations. Surveillance measures and close monitoring of future notification data in the state, with emphasis on children, adolescents, and young adults are necessary for a better understanding of the perpetuation of this public health challenge. [ABSTRACT FROM AUTHOR]

Mangroves provide a unique ecological environment for complex microbial communities, which play important roles in biogeochemical cycles, such as those for carbon, sulfur, and nitrogen. Microbial diversity analyses of these ecosystems help us understand the changes caused by external influences. Amazonian mangroves occupy an area of 9000 km2, corresponding to 70% of the mangroves in Brazil, on which studies of microbial biodiversity are extremely scarce. The present study aimed to determine changes in microbial community structure along the PA-458 highway, which fragmented a mangrove zone. Mangrove samples were collected from three zones, (i) degraded, (ii) in the process of recovery, and (iii) preserved. Total DNA was extracted and submitted for 16S rDNA amplification and sequencing on an MiSeq platform. Subsequently, reads were processed for quality control and biodiversity analyses. The most abundant phyla were Proteobacteria, Firmicutes, and Bacteroidetes in all three mangrove locations, but in significantly different proportions. We observed a considerable reduction in diversity in the degraded zone. Important genera involved in sulfur, carbon, and nitrogen metabolism were absent or dramatically reduced in this zone. Our results show that human impact in the mangrove areas, caused by the construction of the PA-458 highway, has resulted in a loss of biodiversity. [ABSTRACT FROM AUTHOR]

The death of wild vertebrates run over by motor vehicles on highways is one of the main causes of the loss of wildlife diversity. The aim of the present study was to investigate the diversity of wild fauna in roadkill incidents on a stretch of highway in the semiarid region of Brazil. The survey was conducted between March 2020 and May 2021 through active searches using a motorcycle. Killed vertebrates were analyzed and photographed in situ. Wild fauna was studied based on ecological descriptors, speed of movement and average rate of roadkill incidents. We compared total observed richness to that expected using nonparametric estimators. A total of 464 road-killed vertebrates were represented by two species of amphibians, 17 reptiles, 17 birds and 10 mammals. Amphibians were the most affected, totaling 245 individuals. Colubridae was the family with the largest number of species affected. Boiruna sertaneja and Boa constrictor were the only medium-size to large snakes killed. Herpailurus yagouaroundi and Leopardus tigrinus are respectively categorized as "least concern" and "vulnerable" according to the IUCN. The species accumulation curves continued to rise, showing no sign of approaching to an asymptote. Chao 2 and Jack 2 were the main estimators for road-killed wild vertebrates considering total richness. The diversity reported here is considered to be underestimated and greater monthly sampling efforts are required. Conservation strategies are urgently needed for the protection of wild vertebrate fauna to mitigate the staggering loss of biodiversity caused by the construction and operation of roads and highways in Brazil. [ABSTRACT FROM AUTHOR]

• Analysis of data from 2432 survey respondents in Brazil and Ecuador. • More fatalistic individuals tend to hold more dangerous attitudes to road safety. • More fatalistic individuals also perceive traffic risk to be lower. • The relationship between beliefs and attitudes is mediated by risk perceptions. • Patterns of results are highly similar between samples from Brazil and Ecuador. Road safety is a major challenge in the Latin American region; however, there is a significant lack of research undertaken there. To contribute to addressing this gap, this paper reports on an exploration of the antecedents of traffic safety attitudes in two Latin American contexts: Brazil and Ecuador. Building on related work undertaken in other countries, the research explored the relationships between fatalistic beliefs, traffic risk perceptions, and road safety attitudes, while accounting for age, gender, and exposure to the road environment. Data from 2432 individuals, analysed using Structural Equation Modelling, revealed differences in the extent to which different fatalistic belief constructs (including divine control, luck, helplessness, internality, and general fatalism) were related to road safety attitudes. Moreover, fatalistic beliefs were found to influence road safety attitudes both directly and indirectly through their influence on risk perceptions. Those that reported more fatalistic beliefs also reported more dangerous attitudes to road safety and a lower perception of on-road risk. Mirroring findings from work undertaken in other countries, we found males compared to females and younger compared to older respondents to report more dangerous attitudes to road safety, with inconclusive results for risk perceptions. We also found very similar patterns of results in the data from the two countries included in the research. Results are discussed with regards to informing the design of road safety interventions aimed at influencing individual road user attitudes and, ultimately, human behaviour and system performance. [ABSTRACT FROM AUTHOR]

The construction of new roads opens access to native environments, resulting in changes to the landscape. These roads cause the death of native wildlife due to collisions with vehicles, which is the main cause of human-induced vertebrate death. This work aimed to investigate the spatial distribution of roadkills on the BR-163 highway, Mato Grosso, Brazil, an Amazonia–Cerrado transition zone, to identify roadkill hotspots. The study area consisted of 244 km of road. Twenty-five trips were made totaling 6100 km of surveyed roadway between 2008 and 2011. A total of 1005 individuals from 65 species was recorded in this study. Mammals were the most affected, both in number of individuals and species, followed by birds, reptiles, and amphibians. The species with the highest roadkill rates were Cerdocyon thous and Tyto furcata. Identified endangered mammals included Myrmecophaga tridactyla, Chrysocyon brachyurus, Priodontes maximus, Speothos venaticus, Tapirus terrestris, Pteronura brasiliensis, and Ateles marginatus. The highest rates of roadkill were recorded during the wet season. The location and number of hotspots varied among classes and were related to different environmental variables such as waterbodies, forest fragments, and agricultural areas. Roadkills may be a major threat for vulnerable species and should therefore be studied to define conservation plans for local species and road traffic. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Exact Sciences is the property of Master Editora and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: Currently, there are no life cycle impact data available on the construction of road infrastructure in Brazil. This study aimed to determine several environmental impacts associated with the construction of an asphalt-paved highway in Brazil using the life cycle assessment approach and road construction data available from two Brazilian highways. The results from this study can potentially raise awareness to the importance of life cycle thinking in road construction in Brazil. Methods: The processes considered within the asphalt road pavement product system were extraction and processing of sand, gravel, and pitch; transportation of these inputs; and machinery use and operation, including direct and indirect emissions, raw materials, and electricity/fuel. Inventories available in Ecoinvent were used, and processes relevant to the Brazilian scenario were selected, with modifications made when necessary. The ReCiPe method was used to calculate the impacts, and for each category a second method was used to verify the results. The impact categories analyzed were global warming potential (GWP), terrestrial acidification potential (TAP), ozone depletion potential (ODP), freshwater eutrophication (FWEP), marine eutrophication (MEP), and freshwater ecotoxicity (FWECP). In addition, an alternative scenario was considered by substituting diesel with biodiesel in the transportation trucks. Results and discussion: Gravel production was the main contributor to TAP (56% based on ReCiPe) and MEP (62%) categories. It was also a significant contributor to the GWP (16%), FWEP (25%), and FWECP (33%) categories. Transport of raw materials was the most impactful process in the GWP (58%), FWEP (55%), and FWECP (52%) categories. Pitch production was the major contributor to the ODP category (57%). The impact from sand production was negligible for all categories. Machinery operation had a small contribution in all impact categories (less than 14%). The different assessment methods used for each category indicated similar percent contributions for all processes considered (gravel, sand, pitch, transport, and machinery). Substitution of diesel with biodiesel caused an increase in the total impact for all categories, except for ODP. Conclusions and recommendations: Gravel and pitch production, as well as raw material transport, were the most impactful processes in road construction. Therefore, strategies to reduce the impacts of road construction projects should focus on these three processes. In particular, investigation of the environmental impact, using a life cycle approach, of substituting gravel and pitch with alternative or recycled materials should be carried out for the Brazilian context. [ABSTRACT FROM AUTHOR]

During the last decades in Brazil, the developmentalist discourse has promoted several actions that attracted investments for large construction projects. The south coast of the state of Espírito Santo, chosen as the adequate site for investments in transport and logistics infrastructure to support exports and modernize the oil and gas production chain, has been, since the early 2000s, a setting of transformations prompted by the announcement of future installation of ports, thermoelectric plants, construction of roads and railways, among other infrastructures. Such a process does not happen without conflicts. In a recent research focused on environmental conflicts originated from the clash of interests between port investments and fishing communities in the south of the state, it was found that a strategy used by agents to enable "development" was the formation of a discourse that highlights the "empty spaces". This is a qualitative research based on ethnographic immersion, observations, document analysis and interviews with fishermen, government officials and representatives of the enterprises. This article aims to demonstrate the elements used to form this discourse and its opposite, which includes the spaces' plenty diversity, expressed by the presence of traditional artisanal fishing communities. Findings show that the development actions, intending to be homogenizing, do not allow the existence of differences in space, what sparks the disputes that occur on the south coast of Espírito Santo, especially concerning the maintenance of the way of life for artisanal fishermen. [ABSTRACT FROM AUTHOR]

The utilization of construction and demolition wastes routine to the materials and to the dosages' samples, (CDW) in mixtures for construction of road pavements is employing the performing Marshall. The recycleds input an alternative to reduce the consumption of natural showed less apparent density, expressively over aggregates destining correctly those substrates. Sharing absorption, abrasion's test near the natural one, beyond of these concerns, in this research was analyzed the others parameters, respecting the limits required to usage of CDW, in fractions of gravel 1 and sand, in application on the intended destination. From reviews replacement to their natural similar, in the composition about the produced mixtures it was obtained satisfactory of an asphalt concrete, for application in the bearing layer results, attesting positive the use of the recycled of flexible pavement on roads. Were produced two aggregates analyzed in the composition of asphalt concrete's mixtures (one conventional and another concrete, resulting on the execution of an experimental containing CDW), in four percentage of binder, between highway stretch in urban area from Natal county, Rio 4.5% and 6.0%, comparing the fisical and mechanical Grande do Norte, Brazil, however the analyze about the parameters between both. Were applied the tests of stretch is not contemplated in this work. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Business & Projects / Revista de Gestão e Projetos is the property of Revista de Gestao e Projetos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To protect water resources, Brazil's first environmental protection law, known as the Forest Code, was passed in 1934, with the main objective of preserving natural resources, maintaining biodiversity, and promoting water security. Keywords: Amazon; drainage; ecofriendly road; riparian biodiversity; riparian zones; sustainability EN Amazon drainage ecofriendly road riparian biodiversity riparian zones sustainability 1548 1550 3 06/09/21 20210601 NES 210601 Water resources affect ecological and social processes, and riparian vegetation protects these resources, conserves biodiversity, controls soil erosion, and filters pollutants (Riis et al., 2020). [Extracted from the article]

• Roads are a major factor in the ongoing spread of invasive plants. • We examine the facilitative effects of nurse shrubs on native vs. exotic species. • Proportion of exotic species was 27% greater in areas without the nurse shrubs. • Probability of nurse shrubs as facilitators was 61% greater for native species. • Nurse shrubs represent an interesting alternative to mitigate exotic plant invasion. Roads are known to be a major factor in the ongoing spread and establishment of invasive plants by modifying habitats and providing movement corridors. Controlling plant invasion or restoring highly-invaded areas along roads is a challenging task in current conservation practice. We aim to investigate the possible facilitative effects of nurse shrubs on native vs. exotic species in order to provide applications for conservation and restoration of highly invaded roadsides areas in megadiverse montane areas of Brazil. We estimated the abundance of each plant species (native and exotic) in paired roadsides with and without pioneer nurse shrubs (Baccharis spp.), and measured whether they were facilitated (i.e., growing underneath native nurse shrubs), using a Facilitation Value metric. We found that the proportion of exotic species was 27% greater in areas without the nurse shrubs. In addition, predicted probability of nurse shrubs as facilitators of native species was 61% greater than that of exotic species. Pioneer nurse shrubs that alleviate the environmental shift generated by the construction and use of roads (e.g., disturbed soils with low nutrient content) may represent an interesting alternative to mitigate exotic plant invasion along roadsides, a current global priority for biodiversity conservation. Decision-makers considering whether to build, improve, and maintain roads should take into account the potential spread of exotic plants and the use of nurse shrubs to prevent or mitigate plant invasiveness. [ABSTRACT FROM AUTHOR]

Copyright of Anuario do Instituto de Geociencias is the property of Universidade Federal do Rio de Janeiro, Instituto de Geociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The growing demand for aggregates in highway infrastructure makes necessary to search local materials. The objective was to evaluate the inclusion of limestone aggregates in hot mix asphalt mixtures, through laboratory tests. The HMA mixtures were designed by Marshall and Superpave and submitted to indirect tensile-strength, resilient modulus, moisture damage and Flow Number. It was found that HMA mixtures with limestone showed better mechanical behavior, contributed for stiffness and gain of mechanical resistance, mainly to permanent deformation. Relative to moisture damage results, all mixtures were susceptible to water, but even so are technically viable for use in surface courses. [ABSTRACT FROM AUTHOR]

Four analytical models to estimate percent time spent following (PTSF) on two-lane highways were tested with data from 16 sites in Brazil. Besides percent following, the models are based on shockwave analysis, moving-bottleneck theory, or queuing theory. As direct measurement of the PTSF is impractical, PTSF values produced by a simulation program were the basis for comparison (observed PTSF values). The quality of the PTSF estimates produced by the four models was tested using 442 observations and four goodness-of-fit functions [mean normalized error (MNE), mean absolute normalized error (MANE), root-mean squared normalized error (RMSNE), and correlation coefficient r]. Although some degree of correlation between the estimated and observed PTSF values was detected, none of the four models was able to provide reliable estimates of PTSF, as indicated by high mean normalized errors (around 35%) and mean absolute normalized errors that were, on average, close to 50%. [ABSTRACT FROM AUTHOR]

The article explores the halt to the trans-Amazonian migration in Brazil. The authors use the various modes of discourse, from pro-development government propaganda to rainforest-celebrating literature, film, and music, to address the issue. They also discuss the relationship between migration and droughts in the region and the impact of the Transamazonian highway project on the population.

Amazonian deforestation has declined recently, but Brazil's infrastructure plans continue to target the region. In the interest of sustainable development, this article engages the spatial discourses in conservation planning and landscape ecology. It does so by addressing fishbone fragmentation, commonly observed in development frontiers in Brazil. The article demonstrates the importance of road-building by private citizens as key to explaining this particular development geometry. It also suggests that fishbone fragmentation may promote human welfare, and at the same time provide a porous disturbance "filter" with vegetative corridors linking areas of low disturbance across areas of human occupation, thereby enhancing connectivity to support biodiversity conservation. [ABSTRACT FROM AUTHOR]

This study evaluated possible causes of degradation of a microbasin (16 ha) in an area of the Salitre River Basin undergoing desertification, in North-eastern Brazil. Interrill erosion in the microbasin was estimated based on measurements of topography, soil erodibility, rainfall erosivity and land use and occupation. The relief was surveyed by an unmanned aerial vehicle, equipped with precision optical meter. Based on the height, position and local erosion around 53 soil pedestals, the year of their origin was estimated, given that these microstructures resist erosion due to the presence of roots. The sediment yield in the microbasin is 71 Mg ha−1 per year. The dating indicates two main periods of pedestal generation: the first, during which 16% emerged, occurred in the 1960s, coinciding with the construction of an unpaved side road in the upper part of the microbasin. The second, in which 80% of the pedestals originated, dates from the 1990s, when there was intense cultivation of Agave sisalana in the region, even on the steep hillslopes. The dating also identified a significant reduction in pedestal formation during the 1980s, a period in which there was a drop in agricultural production of Agave sisalana in the region. Therefore, two development initiatives (the construction of the local road and the implantation of the Agave sisalana monoculture on the hillslopes) are the most likely factors that triggered the desertification in the area. • Between 1967 and 2019, the yearly production of hillslope interrill sediment yield ranged from 1 to 440 Mg ha−1. • The desertification process might have triggered by a side road construction and monoculture. • The erosion process is until twenty times greater than the rate of soil formation in the area. [ABSTRACT FROM AUTHOR]

This article asks what happens when the colonial dream of a road does not materialize as intended, and becomes instead a permanent project for distant state managers and rural Amazonian settlers. Roads have featured prominently in Brazil’s development designs, and ethnography along an unpaved road demonstrates how a wide array of actors negotiate the tension between the material challenges of moving in Amazonia and the bold modernist figurations that guide highway construction and territorial planning. Over the past 40 years, the unpaved road has itself become a central but unpredictable player in the plans and practices of colonists as well as in emerging governance projects of the Brazilian state. Colonists’ arrival in the region via what they perceive to be an abandoned and impassable road repositions their prefigured relationships with the histories, narratives, and infrastructures of colonial occupation and state-making. Newly local to a frontier zone not yet ‘connected’ to the rest of Brazil, colonists leverage an intimate knowledge of roadside material conditions in an effort to anticipate and influence future state actions. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ibero-Americana de Ciências Ambientais is the property of CBPC - Companhia Brasileira de Producao Cientifica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Neotropical Biology & Conservation is the property of Pensoft Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper features a tool to carry out environmental performance evaluation in highway rehabilitation works, as a component of environmental supervision activities. The procedure involves (i) evidence gathering by conducting technical inspections and reviewing environmental compliance reports, (ii) ranking nonconformities according to a proposed weighting framework, and (iii) calculation of an environmental conformity index. For the sake of testing and calibration, the procedure was applied to five road segments that were submitted to rehabilitation works in São Paulo State and the results were treated qualitatively. [ABSTRACT FROM AUTHOR]

Background: Economic development is often evoked as a driving force that has the capacity to improve the social and health conditions of remote areas. However, development projects produce uneven impacts on local communities, according to their different positions within society. This study examines the spatial distribution of three major health threats in the Brazilian Amazon region that may undergo changes through highway construction. Homicide mortality, AIDS incidence and malaria prevalence rates were calculated for 70 municipalities located within the areas of influence of the Cuiabá-Santarém highway (BR-163), i.e. in the western part of the state of Pará state and the northern part of Mato Grosso. Results: The municipalities were characterized using social and economic indicators such as gross domestic product (GDP), urban and indigenous populations, and recent migration. The municipalities' connections to the region's main transportation routes (BR-163 and Trans-Amazonian highways, along with the Amazon and Tapajós rivers) were identified by tagging the municipalities that have boundaries crossing these routes, using GIS overlay operations. Multiple regression was used to identify the major driving forces and constraints relating to the distribution of health threats. The main explanatory variables for higher malaria prevalence were: proximity to the Trans-Amazonian highway, high proportion of indigenous population and low proportion of migrants. High homicide rates were associated with high proportions of migrants, while connection to the Amazon River played a protective role. AIDS incidence was higher in municipalities with recent increases in GDP and high proportions of urban population. Conclusions: Highways induce social and environmental changes and play different roles in spreading and maintaining diseases and health threats. The most remote areas are still protected against violence but are vulnerable to malaria. Rapid economic and demographic growth increases the risk of AIDS transmission and violence. Highways connect secluded localities and may threaten local populations. This region has been undergoing rapid localized development booms, thus creating outposts of rapid and temporary migration, which may introduce health risks to remote areas. [ABSTRACT FROM AUTHOR]

Copyright of Revista Turismo em Análise is the property of Revista Turismo em Analise and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

El artículo presenta un análisis sobre las políticas públicas dirigidas al desarrollo de la Amazonía brasileña. Entre los aspectos principales destacan una serie de debates de geopolítica entre los más destacadas figuras y políticos brasileños de las últimas décadas. Asimismo, se señalan el papel de las comunidades indígenas, los desarrollos viales de la zona, así como los asentamientos fronterizos.

Brazil has long ago removed most of the perverse government incentives that stimulated massive deforestation in the Amazon in the 1970s and 1980s, but the highly controversial policy concerning road building still remains. While data is now abundantly available due to the constant satellite surveillance of the Amazon, the analytical methods typically used to analyze the impact of roads on natural vegetation cover are methodologically weak and not very helpful in guiding public policy. This article discusses the respective weaknesses of typical geographic information system (GIS) analysis and typical municipality-level regression analysis, and shows what would be needed to construct an ideal model of deforestation processes. It also presents an alternative approach that is much less demanding in terms of modeling and estimation and is more useful for policymakers. [ABSTRACT FROM AUTHOR]

Brazil’s BR-319 Highway linked Manaus, in the state of Amazonas, to Porto Velho, Rondônia, until it became impassable in 1988. Now it is proposed for reconstruction and paving, which would facilitate migration from the “Arc of Deforestation” in the southern part of the Amazon region to new frontiers farther north. The purpose of the highway, which is to facilitate transport to São Paulo of products from factories in the Manaus Free Trade Zone, would be better served by sending the containers by ship to the port of Santos. The lack of a land connection to Manaus currently represents a significant barrier to migration to central and northern Amazonia. Discourse regarding the highway systematically overestimates the highway’s benefits and underestimates its impacts. A variety of changes would be needed prior to paving the highway if these potential impacts are to be attenuated. These include zoning, reserve creation, and increased governance in various forms, including deforestation licensing and control programs. More fundamental changes are also needed, especially the abandonment of the long-standing tradition in Brazil of granting squatters’ rights to those who invade public land. Organizing Amazonian occupation in such a way that road construction and improvement cease to lead to explosive and uncontrolled deforestation should be a prerequisite for approval of the BR-319 and other road projects for which major impacts are expected. These projects could provide the impetus that is needed to achieve the transition away from appropriation of public land by both small squatters and by grileiros (large-scale illegal claimants). A delay in reconstructing the highway is advisable until appropriate changes can be effected. [ABSTRACT FROM AUTHOR]

The expansion of hydroelectric dams that is planned, and under construction, in the Amazon basin is a proposal to generate "clean" energy, with the purposes of meeting the regional energy demand, and the insertion of Brazil into the international economic market. However, this type of megaproject can change the dynamics of natural ecosystems. In the present article, the spatiotemporal patterns of deforestation according to distance from the reservoir in the vicinity of the lake of Tucuruí, and within a radius of 30 km from it, are analyzed. A linear spectral mixture model of segmented Landsat-thematic mapper (TM), enhanced thematic mapper plus (ETM+), and operational land imager (OLI) images, and proximity analysis were used for the mapping of the land-cover classes in the vicinity of the artificial lake of Tucuruí. Likewise, landscape metrics were determined with the purpose of quantifying the reduction of primary forest, as a mechanism of loss of ecosystem services in the region. These methods were also used for the evaluation of the influence of the distance from the reservoir on the expansion of anthropogenic activities. This methodology was used for the scenarios of pre-inauguration, completion of phase I, beginning of construction phase II, full completion of the Tucuruí hydroelectric project, and the current scenario of the region. The results showed that the highest deforestation rate occurred in the first period of the analysis, due to the areas submerged by the reservoir and due to the anthropogenic disturbances, such as timber extraction, road construction, and the conversion of forests into large areas of agribusiness. [ABSTRACT FROM AUTHOR]

Gully development following agricultural land use change is well documented in many tropical developing countries. However, the impact of specific agricultural intensification practices on gully formation, such as the construction of unpaved roads and contour terracing, remains poorly understood. We studied gully formation in catchments with sugarcane agriculture to inform sustainable agricultural management in Brazil. Through field surveys in ten first-to second-order catchments, we mapped erosional features and described gullying along an incision gradient from rill, to ephemeral and permanent gullies. We documented formation of >130 erosional features that concentrated mainly (96%) on dirt roads along the outer margins of streamside vegetation and bordering transitions from hillslope to hollow. We further established a slope-contributing area threshold for gullying, highlighting high susceptibility to gully formation on dirt roads and contour terraces. Key implications of our findings include targeted enhancements of riparian buffers that extend beyond concave topographies as well as the use of topographic thresholds as a benchmark for gully formation along dirt roads in Brazilian sugarcane fields. • Sugarcane-dominated catchments are under substantial geomorphic readjustment. • Gullying occurs mostly along riparian dirt roads located where there is a slope break. • Gullies are forming in geomorphic process domains less prone to channelization. • Adoption of best management practices on roads urgently needed to reduce gullying. [ABSTRACT FROM AUTHOR]

Biodiversity in Latin America is at risk today due to habitat loss, land conversion to agriculture and urbanization. To grow their economies the developing countries of Latin America have begun to invest heavily in new road construction. An assessment of research on the impacts of roads on wildlife in Latin America will help define science-based conservation strategies aimed at mitigating road expansion. The aim of this review was to qualitatively and quantitatively assess scientific research papers addressing road impacts on vertebrate species in Latin America. We searched for scientific papers published as early as 1990 to 2017. We reviewed a total of 197 papers. Published research showed an increasing trend in the last decade with a strong geographic bias with a majority of papers from Brazil. Mammals were the most studied taxa followed by birds, reptiles and amphibians. The majority of studies focused on road mortality and at the individual species level. Studies documented an increase in deforestation rates, in land conversion to agriculture, illegal activities (hunting, logging) and the establishment of human settlements. The effects of roads on species richness and populations abundance varied among taxa with no apparent pattern within taxa. Forest-dependent species tended to avoid crossing roads. Amphibians had the highest median road-kill rate, followed by reptiles, mammals and birds. Our results suggest that there is an urgent need for more research, particularly in Central America and to employ predictive tools for difficult-to-sample or understudied species and critical conservation areas. We recommend a two-speed approach to guide future research: one focusing on quantifying individual species responses towards roads and their implications on population viability; a second consisting of regional or continental-scale analyses and modelling of road risks to species and populations to inform road planning immediately. • Planned roads in Latin America are a threat to biodiversity conservation. • Published research has grown in the last decade with a geographic bias for Brazil. • Studies are focused on road mortality, especially on medium-large mammals. • There is a need for more research, particularly on the impacts of roads at level of genes and populations. • Quantifying individual species responses towards roads and predictive analyses are needed to inform road mitigation [ABSTRACT FROM AUTHOR]