RESUMO
Designing and deploying telecommunications and broadcasting networks in the challenging terrain of the Amazon region pose significant obstacles due to its unique morphological characteristics. Within low-power wide-area networks (LPWANs), this research study introduces a comprehensive approach to modeling large-scale propagation loss channels specific to the LoRaWAN protocol operating at 915 MHz. The objective of this study is to facilitate the planning of Internet of Things (IoT) networks in riverside communities while accounting for the mobility of end nodes. We conducted extensive measurement campaigns along the banks of Universidade Federal do Pará, capturing received signal strength indication (RSSI), signal-to-noise ratio (SNR), and geolocated point data across various spreading factors. We fitted the empirical close-in (CI) and floating intercept (FI) propagation models for uplink path loss prediction and compared them with the Okumura-Hata model. We also present a new model for path loss with dense vegetation. Furthermore, we calculated received packet rate statistics between communication links to assess channel quality for the LoRa physical layer (PHY). Remarkably, both CI and FI models exhibited similar behaviors, with the newly proposed model demonstrating enhanced accuracy in estimating radio loss within densely vegetated scenarios, boasting lower root mean square error (RMSE) values than the Okumura-Hata model, particularly for spreading factor 9 (SF9). The radius coverage threshold, accounting for node mobility, was 945 m. This comprehensive analysis contributes valuable insights for the effective deployment and optimization of LoRa-based IoT networks in the intricate environmental conditions of the Amazon region.
RESUMO
Dams cause profound changes in the structure of environments and local fishing practices. One example of these impacts is the Tucuruí dam, in the southeast of the state of Pará, in northern Brazil. The changes were gradual, but eventually established unique fishery systems and capture techniques that were consolidated over time. The present study used a rapid analysis technique based on the Métier principle to identify 14 fishing systems with distinct characteristics, although a more holistic approach (dimensions: economic, social, technological, and management), supported the identification of four clearly distinguishable groups. From the management perspective, studies of this type are important because they permit the establishment of more effective practices based on the deficiencies found in the different systems or their respective groups.(AU)
As barragens causam profundas mudanças na estrutura dos ambientes e nas práticas de pesca das áreas sob sua influência. Um exemplo dessas mudanças ocorreu na barragem de Tucuruí, no sudeste do Pará, Brasil. As mudanças foram tipologias de pesca graduais e estabelecidas como formas únicas de captura que foram consolidadas ao longo do tempo. Neste documento, usando uma técnica de análise rápida baseada no princípio de métier, foram identificados 14 sistemas de pesca com características particulares, mas, com base em uma observação mais holística (dimensões ecológica, econômica, social, tecnológica e de gestão), quatro grupos de sistemas pesqueiros foram claramente definidos. Do ponto de vista do gerenciamento, estudos dessa natureza são importantes, pois permitem o estabelecimento de práticas de gerenciamento mais criativas, baseadas nas deficiências encontradas nos sistemas ou grupo de sistemas.(AU)
Assuntos
Pesqueiros/classificação , Pesqueiros/história , Meio Ambiente , Avaliação de Danos/políticasRESUMO
Dams cause profound changes in the structure of environments and local fishing practices. One example of these impacts is the Tucuruí dam, in the southeast of the state of Pará, in northern Brazil. The changes were gradual, but eventually established unique fishery systems and capture techniques that were consolidated over time. The present study used a rapid analysis technique based on the Métier principle to identify 14 fishing systems with distinct characteristics, although a more holistic approach (dimensions: economic, social, technological, and management), supported the identification of four clearly distinguishable groups. From the management perspective, studies of this type are important because they permit the establishment of more effective practices based on the deficiencies found in the different systems or their respective groups.
As barragens causam profundas mudanças na estrutura dos ambientes e nas práticas de pesca das áreas sob sua influência. Um exemplo dessas mudanças ocorreu na barragem de Tucuruí, no sudeste do Pará, Brasil. As mudanças foram tipologias de pesca graduais e estabelecidas como formas únicas de captura que foram consolidadas ao longo do tempo. Neste documento, usando uma técnica de análise rápida baseada no princípio de métier, foram identificados 14 sistemas de pesca com características particulares, mas, com base em uma observação mais holística (dimensões ecológica, econômica, social, tecnológica e de gestão), quatro grupos de sistemas pesqueiros foram claramente definidos. Do ponto de vista do gerenciamento, estudos dessa natureza são importantes, pois permitem o estabelecimento de práticas de gerenciamento mais criativas, baseadas nas deficiências encontradas nos sistemas ou grupo de sistemas.
Assuntos
Avaliação de Danos/políticas , Meio Ambiente , Pesqueiros/classificação , Pesqueiros/históriaRESUMO
Anthropogenic threat maps are commonly used as a surrogate for the ecological integrity of rivers in freshwater conservation, but a clearer understanding of their relationships is required to develop proper management plans at large scales. Here, we developed and validated empirical models that link the ecological integrity of rivers to threat maps in a large, heterogeneous and biodiverse Andean-Amazon watershed. Through fieldwork, we recorded data on aquatic invertebrate community composition, habitat quality, and physical-chemical parameters to calculate the ecological integrity of 140 streams/rivers across the basin. Simultaneously, we generated maps that describe the location, extent, and magnitude of impact of nine anthropogenic threats to freshwater systems in the basin. Through seven-fold cross-validation procedure, we found that regression models based on anthropogenic threats alone have limited power for predicting the ecological integrity of rivers. However, the prediction accuracy improved when environmental predictors (slope and elevation) were included, and more so when the predictions were carried out at a coarser scale, such as microbasins. Moreover, anthropogenic threats that amplify the incidence of other pressures (roads, human settlements and oil activities) are the most relevant predictors of ecological integrity. We concluded that threat maps can offer an overall picture of the ecological integrity pattern of the basin, becoming a useful tool for broad-scale conservation planning for freshwater ecosystems. While it is always advisable to have finer scale in situ measurements of ecological integrity, our study shows that threat maps provide fast and cost-effective results, which so often are needed for pressing management and conservation actions.