Notheast Geoscience Journal

Analysis of water quality in springs in different types of land use using the soil-cement method

2024-09-23T17:19:16-03:00

For a long time, spring water was considered pure and clean due to the natural filtration that occurs during the infiltration and movement of spring water through deep and shallow aquifers. However, due to the increase in anthropogenic activities, spring water has shown contamination problems. Various methods for spring recovery are found in the literature, especially in rural areas where spring water is used to supply the population. In the southeast region of the state of Paraná, Brazil, farmers have been applying the soil-cement method to improve the quality of spring water. However, there are few studies on the efficiency of this method. The objective of this article is to evaluate whether there has been an improvement in water quality after three years of using the soil-cement method in springs located in different types of land use (pasture, faxinal, forest, agriculture, and urban). Water samples were collected before the recovery, one year after, and three years after the recovery. At the end of the research, we observed an improvement in water quality, with areas with grazing animals showing the best recovery indices. Some parameters indicated significant improvement, such as E. coli, total coliforms, and turbidity.

Dinâmica do uso e ocupação da terra e seu efeito na temperatura e na precipitação no bioma Caatinga (Floresta Tropical Sazonamente Seca) - Brasil

2024-10-14T10:08:30-03:00

The objective of this work was to evaluate the influence of the dynamics of land use and occupation in the Caatinga on precipitation and temperature. To determine the temperature, precipitation, number of days without rain and of the areas occupied by the classes, the Google Earth Engine platform was used. Precipitation variability was assessed by the Rainfall Anomaly Index. Trend analyzes were performed using the Mann-Kendall test. Pearson's Correlation Coefficient was calculated between climate variables and land use and land cover classes. The dynamics of land use and occupation between 1991 and 2020 demonstrated an advance in anthropized areas. The number of consecutive days without rain, which between 1981 and 1990 had its highest value in September, in subsequent decades, was observed in October. For temperature, an upward trend was observed between 1991 and 2020. It was not possible to establish a relationship between land use and occupation and precipitation. The reduction in the area occupied by larger formations increases the temperature in the region. The change in land use and occupation did not affect precipitation in the region but had a direct impact on air temperature.

Suscetibilidade à inundação de lagos glaciais na sub-bacia Chajolpaya, norte da Cordilheira Real, Bolívia

2023-11-13T11:59:42-03:00

Most of the glaciers across the planet have been retreating in recent decades as a response to global climate change. The loss of glacier area in all regions of the world over the 20th and 21st centuries has resulted in an increase in glacial lakes. The aim of this study was to investigate the flood susceptibility associated with glacial lakes fed by tropical glaciers, located in a pilot study area of the Chajolpaya sub-basin, in the north of the Cordillera Real, Bolivia, using the AHP methodology - Weighted Hierarchical Analysis, with aid of remote sensing and geoprocessing tools. Satellite images were used, referring to the years 1999, 2011, 2015 and 2022, from which 16 glacial lakes in the study area were selected, according to established criteria, to be analyzed and monitored. The results found indicated that two lakes have very high susceptibility to flooding (GLOF - Glacial Lake Outburst Flood), four lakes have high susceptibility to GLOF, six lakes have medium susceptibility, no lake has low susceptibility and four have very low susceptibility to GLOF. These results indicate the existence of cryospheric risks associated with very high and high risk lakes, which can impact downstream communities.

Mapeamento topográfico com aeronave remotamente pilotada para fins de georreferenciamento de propriedades rurais

2024-12-17T11:59:16-03:00

The objective of this study was to evaluate the quality of digital products obtained in topographic surveys using remotely piloted aircraft for the georeferencing of rural properties. The study was conducted at the Federal Institute of Education, Science, and Technology of Maranhão, São Raimundo das Mangabeiras Campus. Three areas with different terrain slopes were selected: 0 to 5%, 5 to 10%, and 10 to 20%. In each area, geodetic surveys were conducted using GNSS and aerial photogrammetry with a remotely piloted aircraft (at three flight altitudes: 70, 80, and 90 meters) to collect coordinates of photo-identifiable topographic points, totaling nine combinations of slope and flight altitude. Digital image processing was carried out using the Structure from Motion technique, resulting in orthomosaics and digital elevation models for each area/flight altitude as the final products. The generated images were evaluated according to the criteria established by the ABNT NBR 13.133/2021 Technical Standard and the Technical Manual for the Georeferencing of Rural Properties - 2nd Edition. It was possible to obtain digital products with high planimetric and altimetric positional accuracy when compared to similar studies found in the literature. It can be concluded that the flight altitude should be configured according to the terrain slope to be mapped. In areas with steeper slopes, it is recommended to conduct flights at lower altitudes to ensure greater planimetric accuracy of orthomosaics and digital elevation models.

A percepção como indicador para melhorias em diagnósticos ambientais prévios de parques eólicos

2024-08-12T11:22:41-03:00

Rio Grande do Norte (RN) is the state with the highest wind energy generation in Brazil. Wind farms are among the projects that generate significant environmental impacts and the populations close to them are the most affected. When it comes to parks with estimated production above 10MW, it is necessary to present the Environmental Impact Study and the Environmental Impact Report (EIA/RIMA). Based on the analysis of the environmental perception of the population affected by projects, it is possible to provide indicators of impacts in the economic, social and environmental spheres, which brought about the previous survey of environmental impacts and subsidize future EIAs/RIMAs. The objective of this study was to carry out a survey, through secondary data, of impacts identified by the environmental perception of residents close to wind farms in municipalities in RN and compare them with those previously identified in the socioeconomic part of the EIAs/RIMAs. The present study brings to light relevant aspects that during and after the construction of these types of projects must be considered through the environmental perception of the population. However, they are not present in EIAs/RIMAs. Thus, it becomes important research for environmental agencies and environmental consultancy companies that request and carry out EIAs/RIMAs respectively, to consider them as prior indicators of social environmental impacts.

Equações de Intensidade-Duração-Frequência de chuvas intensas para Itabuna-BA e municípios limítrofes

2024-08-09T10:29:31-03:00

The aim of this study is to determine the parameters of the intensity-duration-frequency (IDF) equation of intense rains for the municipalities of Itabuna, São José da Vitória, Jussari, Itapé, Itajuípe, Ilhéus, Buerarema, and Barro Preto in Bahia, Brazil. The stations that had more than 20 years of coherent data and whose historical series had records from 1980 were chosen. For each station, the series of maximum precipitation of one day were obtained for the following return periods (TR): 5, 10, 15, 25, 50, and 100 years. Then, the precipitation of one day was disaggregated into smaller intervals of 5, 10, 15, 20, 25, 30, 60, 360, 480, 600, 720, and 1440 minutes. The adjustment of the IDF equation parameters is performed through nonlinear multiple regression, using the Generalized Reduced Gradient (GRG) iteration method. Twelve pluviometric stations were identified within the studied area, but three stations were discarded due to lack of data. Therefore, the data from nine pluviometric stations were adjusted, where the adjustment of the K, a, b, and c parameters of the Intensity-Duration-Frequency equation showed values above the coefficient of determination (R 2 ) of 0.997, demonstrating a very good fit to the observed data.

Efeitos ópticos em gemas produzidas a partir de cristais de feldspato.

2024-08-13T10:51:06-03:00

This article reviews the optical effects of feldspars, a group of minerals with various applications, including jewelry. Feldspars are divided into alkali and plagioclase, and exhibit effects such as adularescence, labradorescence and aventurescence, depending on the mineral intergrowth. The article discusses the gem varieties of feldspar, such as moonstone, labradorite and sunstone, and highlights the importance of crystal orientation in cutting to maximize the optical effects. The article concludes that more research on the optical properties of feldspar can improve gem processing techniques and mineralogical knowledge.

Keywords: optical effect, gemstone, feldspar.

Aplicação de sensoriamento remoto e geoprocessamento da palma forrageira para desenvolvimento da produtividade agropecuária em regiões semiáridas

2024-10-18T10:42:35-03:00

The semi-arid region has a diversified economy in the agricultural sector, but droughts cause great damage to agricultural activity. For this reason, fodder palm has emerged as an alternative for supplying dairy cattle with food. With this research, the spectral signature of fodder palm at different crop ages was determined through remote sensing and geoprocessing, using satellite images. The multivariate analysis showed that the years with above-average rainfall are in opposition to the grouping containing the lowest reflectance values (in the visible and near-infrared bands), which indicate the periods of greatest coverage of the soil surface by forage palm in relation to native vegetation. However, it was possible to monitor the forage palm at different stages of development, providing support for decision-making regarding the management of areas cultivated with palm to increase milk production in the semi-arid region.

Tratamento de Efluentes Domésticos em Sistema Biológico de Membranas Nanocerâmicas para Fins de Reúso Florestal

2024-11-08T15:30:23-03:00

Sewage in Brazil represents 54.1% of sewage collected and 49.1% treated. Therefore, technologies must be innovative to remove contaminants so that they return to the environment within standards. Among the technologies: Water Quality Unit, traditional HDPE designed for the separation of solids and oils and a nanoceramic membrane reactor called Biogill, which has aerobic, anaerobic and anoxic phases associated with a BOD removal efficiency of 90% and nutrients of 80%. To contribute to the increase in these rates, an ETE was built in a residential building located in the city of Barra de São Miguel. The treated sewage was reused to produce Aroeira do Sertão and Ipê Roxo seedlings, as well as a morphophysiological and statistical analysis of the seedlings in relation to production with drinking water. Among the results: full compliance with CONAMA resolution nº 430/11; compliance with reuse standards ABNT NBR 13.969/1999, PROSAB, COEMA nº 2/2017 and SES/SMA/SSRH nº 1/2017, except turbidity and BOD, requiring improvements in tertiary treatment. Finally, the effluent showed better results for the development of seedlings than water, however, using ANOVA and Tukey's test (p<0.05), no significant classification was obtained.

Impacto do fogo sobre a macrofauna edáfica em área de cerrado no município de São João do Sóter – MA

2024-04-05T09:13:14-03:00

The study of soil macrofauna is used to monitor environmental disturbances and degraded areas. Fire is one of the agents with the greatest potential to drastically modify the environment and landscape, and can cause environmental and economic damage. The aim of the work is to analyze the effect of fire on the soil macrofauna community in a cerrado area. The material was collected in the rainy season (March 2021) in Povoado Serra do Cajuí, municipality of São João do Sóter – Caxias MA. To collect the specimens, pitfall traps were used. 15 points were delimited with a distance of 450m from each other. These points were demarcated into burned area (Area 1), little burned area (Area 2) and unburned area (Area 3). A total of 3,876 individuals were found distributed across 11 orders, with 8 orders found in Area 1, 10 orders in Area 2 and 9 orders in Area 3. Area 2 presented the greatest abundance, and among the three Areas, the order Hymenoptera is the most abundant, dominant and frequent. Area 1 presented the highest Diversity and Uniformity index and Area 2 presented the highest Wealth index. The richness estimator suggests greater sampling effort.

Multitemporal Analysis of Land Use and Cover in the Marine Extractive Reserve of Bay do Iguape – Recôncavo Baiano

2024-08-30T10:43:26-03:00

The present work aimed to analyze the dynamics of land use and coverage in the Marine Extractive Reserve of Baía do Iguape, using Landsat images from 1986, 1994, 2003, 2017 and 2022. RESEX Baía do Iguape, covers the municipalities of Cachoeira , São Félix and Maragogipe, located in Recôncavo Baiano. 
The methodological procedures included bibliographic research, organization of a geographic database in a GIS environment, data tabulation, digital image processing and creation of maps. To carry out land use and cover mapping, the vectorization method was chosen. 
The accuracy of the mappings for the global accuracy and Kappa indices were above 90%. At RESEX Baía do Iguape, over the last 36 years (1986 to 2022), there has been an expansion of the mangrove area of 1.8 km2, a reduction in the agricultural class and an increase in dense rainforest vegetation. In this context, multi-temporal analyzes of land use and cover are considered essential, which allow knowing the targets that are exposed to the likely impacts of rising mean sea levels, contributing to the planning and coastal management of the reserve and the formulation of policies public projects aimed at the fishing communities that are located there.

Análise de estabilidade de taludes usando uma abordagem probabilística

2024-03-08T10:35:19-03:00

This paper presents a study that utilizes computational implementations of the FOSM and Monte Carlo methods. These methods aim to determine the probability of slope rupture in areas prone to shallow landslides. The study focuses on the Vila Rabelo region situated in the administrative zone of Sobradinho II, Federal District. The computational approach involves two distinct programming tools: MATLAB for the FOSM method, and FORTRAN for the Monte Carlo simulation method. The analysis reveals that the Monte Carlo method tends to yield higher maximum rupture probability values compared to the FOSM method, particularly in steep terrain. A convergence analysis for the Monte Carlo method was undertaken to illustrate how the appropriate number of simulations is determined. Furthermore, findings indicate spatial proximity and occasionally higher values in the spatial distribution of rupture probabilities obtained from the Monte Carlo method compared to the FOSM method. The variations in rupture probability values achieved through probabilistic methods stem from the distribution configurations of the cohesion variable, which is one of the input data.

Circuitos produtivos e a participação da agricultura familiar na suinocultura brasileira

2024-05-17T08:12:49-03:00

The objective of this study is to analyze the productive dynamics and the participation of family farming in Brazilian pig farming, especially in light of local and global technological changes in recent years. The research is quantitative in nature, with the collection, processing, and analysis of secondary data from the 2006 and 2017 Agricultural Censuses regarding pig farming in Brazil. Regarding the analysis of the results, the quantitative data were treated using descriptive statistics adjusted for each variable studied. The results indicate the presence of pig farming throughout Brazil, with a strengthening, in recent years, of integrated production systems in the South and Southeast regions, and production focused on subsistence in the North and Northeast. The main conclusion is the relevance of pig farming for the reproduction of ways of life and its influence on international markets through exports, in addition to the need to rethink the current model, since the basis of the pig diet, corn, is exposed to climate and market fluctuations. It is also important to explore alternative markets, fostering this activity beyond conventional models. The Brazilian government needs to pay special attention and support to family farming, which is the main producer in the country. Although integration with agribusiness brings benefits, such as access to markets and stability, it also increases farmers' dependence, requiring public policies and industry actions that consider these vulnerabilities.

Richness, diversity and faunal similarity estimators of soil spiders (Arachnida: Araneae) in two vegetation formations of the Cerrado biome

2024-04-05T09:11:15-03:00

Studies on soil araneofauna in the Cerrado biome are still scarce in northeastern Brazil, especially in Maranhão. This study aimed to conduct an inventory of richness, diversity, and faunal similarity estimators of soil spiders in two vegetation formations of the Cerrado biome, namely gallery forest and Cerrado sensu stricto, in the Inhamum Municipal Environmental Protection Area (EPA), Caxias, Maranhão, Brazil. Collections were carried out during dry and rainy periods using Provid-type traps. For faunal analysis, species richness, diversity and equitability tests were used in the Anafau program and faunal similarity tests in the R program. In the present inventory, 23 families, 37 genera, and 43 species were identified. Richness estimators and species accumulation curves generated for both sites (gallery forest and Cerrado sensu stricto) revealed that the sampling effort was not sufficient to fully quantify soil araneofaunal species; therefore, the richness of soil spiders at the two analyzed sites of the Inhamum EPA is underestimated, suggesting that it might be possible to record even higher richness values in the two studied vegetation formations of the Cerrado biome. The Shannon–Wiener diversity index (H′) and Pielou's evenness index (J′) were similar and indicated a moderate diversity of soil spiders in both gallery forest and Cerrado sensu stricto sites. Similarity dendrogram analysis showed that the soil spider communities analyzed were substantially similar, with most species occurring at both sites.

Análise espacial de correlação entre o índice de desenvolvimento humano e as atividades agropecuárias na Ilha do Marajó, Pará, Brasil

2024-12-20T11:47:13-03:00

The economy of Marajó Island is shaped by activities such as livestock farming—particularly buffalo farming in the island’s natural fields—forest extraction, and small-scale agriculture, which have been practiced since colonial times. In light of the region's low Human Development Index (HDI) scores, this study examines the correlation between agricultural activities and HDI across the municipalities of Marajó Island. The methodology involved organizing HDI data and agricultural census information for the centroids of 16 municipalities and applying the Inverse Distance Weighted (IDW) method to spatialize these attributes. Due to the non-normal distribution of the data, Spearman’s correlation was employed. The results revealed a moderate positive correlation between buffalo farming and pineapple cultivation with HDI, indicating that these activities, along with tourism, contribute to improvements in human development. In contrast, poultry farming showed a moderate negative correlation, suggesting it may reflect a form of local economic resilience. This study contributes to understanding the relationship between specific agricultural activities and human development in a region that has received limited research attention. By utilizing spatial analysis, it provides new insights into the interplay between agricultural practices and HDI, emphasizing the need for locally tailored strategies to foster sustainable development.

Análise dos efeitos da refração no monitoramento de barragens Estudo de Caso UHE Governador Jayme Canet Junior

2024-04-30T08:55:18-03:00

The influence of atmospheric refraction on dam monitoring is a topic that requires study and discussion, due to variations in atmospheric conditions caused by the region's specific characteristics. The study site is the dam of the Governador Jayme Canet Junior Hydroelectric Plant, located between the municipalities of Ortigueira and Telêmaco Borba, in the state of Paraná. Due to the construction of the dam, the region has a large flooded area and downstream a large roller-compacted concrete (CCR) structure that absorbs solar radiation throughout the day, generating an important temperature gradient. The research evaluated variations in temperature, pressure and humidity throughout the day in determining the coordinates of monitoring points, using topographic irradiation with a total station, together with an automatic search system for the point to be monitored. To this end, a survey of these points was carried out using three different geodetic landmarks, two upstream and one downstream, with the purpose of calculating the coordinates of two geodetic landmarks located on the crest of the dam called CG01 and CG02. The results show that, even after correcting the distances depending on meteorological conditions, the calculated coordinates showed discrepancies and this variation suggests that possible errors may be due to the effects of refraction in the measurements of horizontal directions and vertical angles, as we observed a behavior where the average coordinates are more influenced by the point occupied in the survey than by the time of day. Analyzing the error ellipses, it is possible to verify that the biggest variations were in the morning, which suggests that solar incidence can cause a change in the refractive index in the region and consequently in the coordinates.

Uso da Classificação Geomecânica RMR Relacionado à Estimativa de Auto Sustentação em Mina Subterrânea de Sal

2024-03-08T10:16:23-03:00

Geomechanical classification in a salt mine (especially a potash mine) is based on the following parameters: position and angle of the stratified layer, thickness of the strata, immediate roof of the excavation, distance to the top of the waste rock layer, depth, orientation of the plough and clay thickness. Because there are few underground salt mines, scientific studies and publications have always been limited, especially those related to geomechanical classifications. The initial study aims to verify if the RMR (Rock Mass Rating) system proposed by Bieniawski (1973) can be adopted to correlate the specific stand-up time in the mine. Using statistical studies, it was observed that the RMR system showed strong correlation with the maximum stable opening time and can be useful in predicting the roof self-support time.

Estudo hidrológico da área do lixão do Roger em João Pessoa-PB, Brasil

2025-01-10T11:25:58-03:00

The recurrence times or return periods of intense precipitation can be obtained from estimates, making it possible to evaluate the flooding caused by the rise in the water level of water bodies in a region. Such an assessment makes it possible to map water spots and thus verify the areas that could be affected by floods. In this context, this work aimed to evaluate historical precipitation series from pluviometric stations located close to the Lixão do Roger area in João Pessoa-PB, estimate maximum precipitation using continuous probability distribution (Gumbel) for different recurrence times and map the floods generated by these precipitations associated with the recurrence times studied, aiming at safety in the area for the implementation of a park. Using hydrological modeling and delimitation, it was possible to identify the flood areas in the Lixão do Roger area and predict the altitude reached by the flood spots for each recurrence time. For the Cabelo Cagepa Post and considering a recurrence time of 100 years, it is possible to verify that up to 30% of the Lixão do Roger area is affected by floods and the elevation intercepted by the water was approximately 5.87 m.

Propriedades estatísticas das séries históricas de cota e vazão da bacia do rio Doce

2025-01-08T16:08:33-03:00

The Doce River Basin holds immense socio-environmental, economic, and cultural significance, playing a vital role in the lives of local communities, regional biodiversity, and the preservation of water resources. For water resource planning, historical data series are commonly used. However, these series are not always statistically analyzed prior to use. Therefore, this study employed non-parametric tests using the statistical software R to assess the randomness, independence, homogeneity, and stationarity of the monthly mean water level and flow rate series of this basin. The results indicated that none of the stations had random series; four stations had independent series (three for water level and one for flow rate); 128 stations had homogeneous series (58 for water level and 70 for flow rate); and 148 stations had stationary series (76 for water level and 72 for flow rate). In conclusion, the historical data series exhibit consistent variations and should be thoroughly analyzed before being utilized.

Estabilidade nas estradas da Amazônia brasileira: um recorte da BR-010 no Estado do Pará

2024-11-08T15:27:58-03:00

In Brazil, road construction processes started in the 1930s but were intensified in the 1960s due to the projects of national integration. Building a road requires the application of various geotechnical solutions, among other studies, to ensure the correct execution of the project. Slopes are commonly deployed, particularly in regions of rugged terrain, presenting steep inclines and declines. In this research work, slopes six were analyzed along, approximately, 36 km of the BR-010 road, in the Paragominas and Ipixuna do Pará, municipalities of Pará State in Brazil. These presented values of safety factors within the recommended limits; however, erosion and mass movement problems occur in most of them. Hence, it is necessary to employ preventive treatment to avoid block falls and landslides that could obstruct the road causing traffic interruption, environmental and economic harm or, even worse, detriments to human lives.

Avaliação Geoespacial da Dinâmica Espaço-Temporal da Linha de Costa de São José da Coroa Grande, Pernambuco, Brasil

2024-12-23T08:58:35-03:00

Coastline monitoring is essential to understanding the impact of human activities and climate change on the coastal zone. Regular monitoring of the position of the coastline is extremely important to analyze and select the most effective engineering solutions to contain coastal erosion, in addition to supporting a sustainable coastal management system. This study aims to evaluate the evolution of the coastline in São José da Coroa Grande, Pernambuco, over the last 49 years, using remote sensing techniques such as satellite images, unmanned aerial vehicles (UAVs), in addition to GNSS surveys. Coastal progradation and retrogradation rates were calculated, identifying the geomorphological elements that influence changes, such as erosion and sediment accumulation. The results revealed consistent patterns of erosion and accretion over the decades examined (1974, 1981, 1997 and 2023), highlighting a section with erosion of up to -114,291 m/year between 1974 and 1997. The study also highlighted seasonal dynamics of progradation and retrogradation in the area. It is recommended to integrate high spatial resolution remote sensing data and GNSS with oceanographic information for a more complete understanding of coastal changes in future research.

A comparative analysis of metal bar bending under loads, using different geodetic methods: geometric leveling, trigonometric leveling and close-range Photogrammetry

2024-07-15T10:06:09-03:00

The analysis of bending and deformation of metallic structures are an important part in monitoring these structures. Understanding its behavior under stress (displacements) is important to guarantee safety and durability when used in structures or even to ensure that they behave as designed. In this context, the use of advanced geodetic measurement methods plays a role. This study focuses on the analysis of the bending of a metal bar using three different measurement methods: close-range terrestrial photogrammetry, leap-frog trigonometric leveling and precision geometric leveling. Each of these methods has its own advantages and challenges. Throughout this work, its characteristics are explored, as well as the steps involved in data collection and processing, contributing to a more comprehensive understanding of the possibilities and limitations in the bending analysis of structures. The results of this study indicate that the three chosen methods are capable of monitoring structures like the one chosen here, for the loads adopted here, with maximum differences between the results for the three methods in the order of 1mm, when the maximum load is applied.

Análise numérica bidimensional e tridimensional de estabilidade de talude de grande altura em mina a céu aberto

2024-03-19T09:43:01-03:00

The slope stability analyzes most commonly used in geotechnical engineering practice are in two dimensions. However, the evaluation in three dimensions tends to be more rigorous, and more justifiable to represent the real condition of the geometry of the unstable terrain mass. Thus, advances in the theory of three-dimensional stability analysis, the increase in the processing power of personal computers and the development of more robust software packages, have allowed engineers, designers and researchers to present these analyzes in a more assertive and pragmatic way. In this way, the article develops the analysis of the two-dimensional and three-dimensional slope stability of a pit of an open-pit mine located within the Mineral Complex of Patrocínio-MG, with height in the order of 375m, with banks of 10m, evaluating the consistency of the database available and, in sequence, the results obtained. The geology of the region is characterized by an economic alkaline deposit of phosphate that occurs in the central area located entirely within the Salitre I dome. Rocscience®. The stability method adopted for the present research was the General Limit Equilibrium Method (GLE) proposed by Morgenstern-Price (1965) for two-dimensional problems with lamellae (slices) of 1 (one) meter thickness, later adapted for three-dimensional problems, where 2D lamellae were replaced by 3D columns, thus generalizing their use. A safety factor was then obtained with the average resistance parameters of the materials of 1.22 2D and average (FS) 1.32 3D, close to the minimum (FS) = 1.30 recommended by several authors for pit slopes, enough to define an unstable slope condition. Considering the 2D analytical model as a reference, in absolute terms, the difference between the analyzes is around 8.2%, thus showing convergence between the analyses.

Keywords: 2D and 3D stability analysis, limit equilibrium, automatic search, critical section, open pit mine.

Avaliação da estabilidade de uma barragem de rejeitos de mineração de ferro

2024-03-15T08:49:45-03:00

In engineering practice, the evaluation of dam stability is commonly done in a deterministic way, using Limit Equilibrium Methods. However, probabilistic methods have been increasingly accepted as a complementary analysis tool to represent the real condition of soil variability in the field. Thus, the article presents an evaluation of the stability of an upstream tailings dam, in the iron mining region of Minas Gerais, Brazil. In the research, the commercial program Slide 2D from the company Rocscience®️ was used. The stability studies adopted in the present work were based on the Limit Equilibrium Method proposed by Morgenstern-Price (1965). Probabilistic analyzes were carried out, using the classic methods of Monte Carlo (MC) and FOSM (First Order Second Moment), obtaining a deterministic factor of safety (FS) in the order of 1.06, for the condition of the previous dam rupture. The value of probability of rupture (Pr) by the FOSM Method was 27.0% (or 1:3.7), with a reliability index (β) equal to 0.621. Using the MC Method, Pr = 25.6% (or 1:3.9) and β = 0.705 were obtained. It appears, therefore, that both methods indicated a precarious condition of the stability of the dam, which broke in 2019.

Utilização de geotecnologia no estudo das “Terras Caídas” na Terra Indígena barreira da Missão, Tefé/Amazonas/Brasil

2024-04-10T19:41:47-03:00

The “Fallen Lands” are morphodynamic processes that occur mainly in Amazonian rivers and that cause significant changes in landscapes, including triggering material and human losses. This study aims to characterize and analyze physical-natural events by determining formation/change rates of Fallen Land processes in the Barreira Indigenous Land (Tefé/Amazonas) based on the use of geotechnologies. Methodologically, the tools available in Google Earth Pro were used to collect, process and interpret spatial data (elevation profile, drainage, vegetation and soil coverage) and human activities (economic and housing occupation) along the erosion scars. As an analytical parameter, 20 features were determined (five in each indigenous community) demonstrating the variety of the process in its geometries, dimensions and spatio-temporal behavior, such as Feature 05 located in Barreira de Baixo, with an 80 meter perimeter of the erosion scar. The results identified can be useful for the implementation of social and environmental public policies aimed at improving the quality of life of the populations that inhabit these areas, considering that the process intensifies over the years.

Análise do impacto ambiental na qualidade da água subterrânea de cemitérios – Caso do cemitério municipal localizado no município de Recife, Pernambuco – Brasil

2024-10-28T11:56:05-03:00

Among the United Nations' Sustainable Development Goals (SDGs) is the quest for universal access to quality water by 2030. SDG 6 aims to ensure the availability and sustainable management of water. According to the latest SDG progress report published by the UN (2023), 2.2 billion people still lack access to drinking water, one of the problems being water contamination. Among the sources of contamination are cemeteries, which has been aggravated by the Covid-19 pandemic. The aim of this work is to assess possible groundwater contamination in the largest cemetery in the state of Pernambuco, Brazil, the Senhor Bom Jesus da Redenção Cemetery, Recife. To assess the vulnerability of the water, laboratory and field studies were carried out to determine the levels of heavy metals, COD, BOD and pH in samples collected from the cemetery. The data is compared with water collected from the state supply system. The effect of recent burials is observed in the average phosphorus content of the soil samples tested (471, 81 mg/kg), as well as changes observed in the concentrations of heavy metals and physical-chemical parameters indicating that the groundwater in the cemetery is suffering interference in its quality due to recent burials.

Geodiversidade do Vale do Jacaré, Regeneração, Piauí, Brasil: potencialidades e valores

2025-01-10T08:49:16-03:00

In Piauí, research involving geodiversity has been developed in the last decade, and despite the growing number, they are still insufficient. Given this scenario, the work aimed to inventory the geodiversity of Vale do Jacaré, municipality of Regeneração, Piauí, emphasizing its potential and associated values. A literature review, office and field research were carried out. The studied municipality reveals potentialities from the point of view of its geological, geomorphological and hydrological heritage, in view of the occurrence of mountains, caves, lakes and canyons. It is recommended that these locations be used as a way to boost geoconservation strategies and the local-based economy, enabling the municipality's economy to become more dynamic. It is expected that the work of different spheres of public power, combined with private initiatives, especially local residents, will implement measures that guarantee the conservation, dissemination and promotion of this valuable geodiversity.

Avaliação da influência de variáveis naturais na temperatura do ar através de regressão linear

2023-11-13T11:49:09-03:00

Air temperature is a factor that directly affects the physiological processes of plants and animals. Therefore, its understanding has become essential in analyzing the adaptations of fauna and flora in certain areas, as well as in studies related to human thermal comfort. However, a major obstacle to this territorial characterization is the lack of a dense network for monitoring climatic data. Various methods have been applied to estimate temperatures in areas without meteorological data, including multiple linear regression equations. This study aims to create a model to predict the average air temperature based on altitude, latitude, longitude, and surface temperature obtained from orbital sensors. The choice of the study area encompassed the states of the South, Southeast, and Mato Grosso do Sul, with 319 weather stations. The resulting regression model achieved an R² of 0.74. Temperature predictions and residuals were generated, highlighting higher temperatures in the Midwest, demonstrating the influence of the continentality phenomenon, and lower temperatures in mountainous areas due to altitude. This study underscores the importance of climate monitoring in understanding geographical influences on air temperatures.

Meio físico e impactos ambientais na mata ciliar do baixo curso do rio Groaíras, Ceará

2024-04-10T18:14:00-03:00

Studies related to watersheds should consider not only the physical environment, but all the structural physiographic elements of the landscape. Based on this premise, this work aimed to characterize the physiography of a stretch of the low course of the Groaíras River, Northwestern Ceará, relating the physical environment with the riparian forest ecosystem and the main environmental impacts observed in the area. The research was carried out from bibliographic surveys and field observations, during the period from august 2020 to september 2021. The results indicate that some of the environmental components of the study area are still preserved, especially the geomorphological features of the river channel, which have been protected by the remnants of the riparian forest. It is believed that the maintenance of the riparian forest occurred due to the extraction of carnauba wax (Copernicia prunifera (Mill.) H.E.Moore), a socioeconomic activity that is currently threatened, not only by the demand for agricultural areas and inputs for the potteries, but also by the bio-invasion of the witch's claw (Cryptostegia madagascariensis Bojer), an invasive exotic plant.

Geoprocessamento aplicado à avaliação de Áreas de Preservação Permanente de nascentes inseridas na área de influência do Complexo Portuário de Suape

2024-10-14T10:22:48-03:00

Springs are water bodies that are essential for the ecological balance of river basins, which are ideal units for use in environmental studies. Therefore, sought to evaluate the springs and their Permanent Preservation Areas, including the microbacteria of Riacho Algodoais, in the area of influence of the Port of Suape, using geotechnologies, such as the Mapbiomas program. The methodology consists of creating thematic maps and collecting quantitative data, analyzing from 2002 to 2022 variations in land use and occupation and contour dynamics that can influence the flow of water in the soil, such as the transport of materials and a possible distribution of contamination in the area. In the selected period, an increase was observed in the Urbanized Area class (+ 77.17%), as well as in Forest Formation (+ 53.51%). However, there was a reduction in the River, Lake and Ocean (-59.55%), which includes the water bodies in the research area. The study showed similarity with related publications, demonstrating that geotechnologies are effective tools for environmental monitoring, with an accurate approach to vegetation cover and contributing to the implementation of appropriate measures. Furthermore, they are essential in preventing and mitigating problems resulting from adverse environmental impacts caused by the interaction between human activities and the environment.

Influência da biodegradação no desenvolvimento de recalques em resíduos sólidos urbanos cobertos com uma cobertura intermediária de aterros sanitários

2024-12-13T10:03:22-03:00

Physico-chemical parameters of landfill leachate such as chemical oxygen demand (COD), electrical conductivity, pH, ions, etc. are useful for investigating the biodegradation phases of municipal solid waste (MSW) and can be determined through laboratory analysis. Given that biodegradation is responsible for a large part of the settlements that occur in MSW landfills, it is essential to monitor the biodegradation phases of the waste mass. These parameters do not behave individually, as they are interconnected. The use of lysimeters installed in the field, exposed to environmental conditions, makes it possible to simulate the degradation behavior of the waste mass. In this study, 3 lysimeters were built, containing MSW and covered by an intermediate cover layer from landfills in the state of Ceará, with different MSW compositions and surface drainage conditions (with and without leachate recirculation). In the lysimeter without recirculation, a decrease in COD was observed compared to the lysimeter with recirculated slurry. The recirculation of leachate contributed to greater settlements and to making the leachate more concentrated with salts such as chlorides, which directly influenced the increase in electrical conductivity.

Geotechnical treatment analysis for headrace tunnel in gneissic rock mass

2025-01-10T10:49:19-03:00

This article presents the methodology adopted for the geotechnical design of the support applied to the headrace tunnels of the Laúca Hydropower Plant (AHE Laúca), located in Angola. The plant's headrace system consists of six parallel tunnels, each with an average length of 1900 meters, excavated in a gneissic rock mass. To determine the supports required to maintain excavation stability during the construction phase and the plant's operation, geological and geotechnical tests and investigations were conducted. The results of these investigations supported the studies presented here, providing parameters such as compressive strength and deformability of the rock mass, as well as shear strength of the rock mass discontinuities. The definition of appropriate support to ensure excavation stability was based on the Q-system rock mass classification. After the preliminary design of the support for excavations in competent rock mass, classified as Classes I to III, the proposed support was subjected to verification and validation through local stability analyses. These analyses were performed using the Unwedge software for the End of Construction load case, and a combined approach of local stability and coupled flow analysis using the Unwedge and Phase software for the operational phase load condition. The results highlighted the necessity of a drainage system consisting of perforated drains in the rock mass, in addition to the standard treatment comprising anchors and shotcrete. This system was crucial for reducing pore pressures acting on potentially unstable wedges around the excavations, particularly in scenarios where one tunnel remained empty while the others were in operation. Currently, all tunnels in the project are in operation and have undergone emptying processes due to operational demands. On none of these occasions were issues observed with the tunnel floor, nor were there any reports of block falls from the walls or crown.

Permeabilidade, Drenagem e Instrumentação em Maciços: Estudo e Aplicações em Barragens

2025-02-21T13:33:40-03:00

This article addresses the influence of permeability and water percolation velocity in soil masses, highlighting their variation according to grain size and sensitivity to the amount of water present. Permeability is directly linked to the medium's porosity, influencing soil drainage. Tables are presented with permeability and drainage characteristics of various types of soil, as well as average consolidated permeability values of common materials used in dam embankments and their foundations. The negative effects of water infiltration in embankment dams are also discussed, such as soil particle displacement and leaching, emphasizing the importance of adequate drainage systems. Additionally, empirical criteria and probabilistic models for the design of drainage and filtration systems for dams are described, aiming to control percolating fluids and ensure the structures' safety. Instrumentation in dams, especially in Brazilian territory, is also addressed, highlighting its fundamental role in the monitoring and control of structures.

Zoneamento Eólico e Transporte dos Sedimentos na área dos Corredores Eólicos do PARNA de Jericoacoara, Ceará, Brasil

2023-06-30T12:14:52-03:00

The study analyzed the behavior of sediment transport in the Beach Zone located between Praia do Preá and Jericoacoara in the Jericoacoara National Park - PARNA.

The physical limitations of in situ measurements of sediment transport on beaches, mainly longitudinal, restrict studies in these environments to the subaerial part. Sediment trap methods were chosen, with 04 collection and measurement campaigns being carried out for reconnaissance, carried out between July 2019 and February 2022, where eleven trap points were delimited, comprising the beach sectors and the wind corridors of transportation and feeding of Duna Por do Sol (DPS). Three sediment traps were used for each collection point, spaced 5.00 meters apart.

With the results obtained, an eolic-sedimentary zoning was carried out, presenting the processes and effects of the local wind dynamics (erosion and sedimentation), understanding how the morphological dynamics of the area occurs and correlating it with possible scenarios, essential elements for the planning that aimed at mitigating impacts and requalification of the area in the medium and long term, resulting in a project that will try to stop the sediment balance deficit in the DPS, contributing to its recovery in volume and area, with the installation of sets of Wind Current Guide Structures (EGCE).

Análise mineralógica e aplicações tecnológicas do resíduo da extração de esmeraldas dos Garimpos de Carnaíba e Socotó/BA em composição de massas cerâmicas

2025-02-21T13:58:58-03:00

Emerald mining in the Carnaíba and Campo Formoso Mountains, in Bahia, generates significant environmental waste. This study aimed to characterize the waste from the Carnaíba (Pindobaçu-BA) and Socotó (Campo Formoso-BA) mining sites and to develop clay-based composites for the production of ceramic materials in civil construction. Formulations were prepared with varying concentrations of clay and mineral residues (10, 20, 30, 40, and 50 %) and were subjected to chemical and mineralogical analyses using X-ray fluorescence and diffraction. The samples were sintered at different temperatures (850, 900, 950, 1000, 1100, and 1200 ºC) and underwent technological tests (water absorption, apparent porosity, linear shrinkage, loss on ignition, apparent density, and flexural strength). The results revealed favorable characteristics for the ceramic industry, with the predominant presence of SiO₂ and Al₂O₃ affecting plasticity, and fluxing elements influencing thermal properties. The mineralogical diversity, including mullite, metakaolinite, indialite and quartz, contributed to the composites' strength and stability. The C20 (20 % Carnaíba residue) and S10 (10 % Socotó residue) formulations showed the best results, standing out for their technical feasibility and sustainability in ceramic production.

Modelos preditivos para análise da variação da Altitude da Superfície do Mar utilizando leituras marégráficas

2024-12-20T11:37:21-03:00

Evaluating Sea Surface Altitude (SSA) is crucial for predicting the consequences that global warming may have on coastal cities, as well as for establishing a reference altimetry. Monitoring this altimetric component can be conducted through tide gauges or Satellite Altimetry (ALTSAT). The aim of this research was to analyze the readings from the tide gauge in Fortaleza, Brazil, to determine the SSA and generate predictive models for the variation of this component. Based on a five-year sample of readings, a linear regression was conducted using the statistical software R. Starting in 2020, there was a change in the measurement pattern of the readings, which significantly impacted the validation of the models. The average variation of the SSA was 1.0198 cm ± 0.2034 cm, suggesting an increase in sea surface elevation at the location.

Incidência do Amarelecimento fatal da palma de óleo em resposta à resistência a penetração do solo

2025-01-23T15:29:00-03:00

Studies on abiotic factors have gained increasing attention in research on Fatal Yellowing (FY) of oil palm (Elaeis guineensis Jacq.). The application of geostatistical techniques, especially ordinary kriging, enhances the analysis of these factors, providing a more holistic view of the study environment. This study aimed to analyze the influence of Soil Penetration Resistance (SPR) on the incidence of FY in oil palm, using geostatistical techniques. The study was conducted at Nogami Farm, in Igarapé-Açu (Pará State), in a 6.3-hectare oil palm plantation with 10.24% of affected plants. After measuring the SPR using a soil penetrometer, the data were subjected to descriptive and normality tests, followed by the construction of the semivariogram and the application of ordinary kriging, generating the thematic map of the spatial distribution of SPR. Based on the georeferenced phytosanitary inventory and the map, the SPR for each plant was determined, forming two groups: Plants with FY and Plants without FY. Given the non-normality of the data (Shapiro-Wilk test), the Mann-Whitney test was used, revealing a higher prevalence of FY in areas with higher SPR.

ANÁLISE DA DINÂMICA DO USO E COBERTURA DO SOLO NO MUNICÍPIO DE ITABUNA, BAHIA

2025-01-10T11:17:12-03:00

Using data from remote sensing as a basis for studies on mapping land cover and use is a world-renowned practice, as it allows a dynamic and spatial analysis of the different classes existing in the territory. In this context, the main objective of this work was to analyze the dynamics of land cover and use in the municipality of Itabuna-BA, from 1985 to 2021, through data obtained by remote sensing. The data used came from MapBiomas project, and the processing and analysis of this data was carried out with the help of QGIS and Excel software. The results revealed a significant replacement of Forest Formation class by other categories, such as Pasture, Mosaic of Uses and Urbanized Area. The evolution of urban areas in the municipality was also observed, with a significant increase in the Urbanized Area class from 2003 onwards. Furthermore, there was a growing process of urbanization and irregular occupation of preservation areas along the Cachoeira river. Through the results found, we can see the importance and urgency of implementing public policies aimed at environmental conservation and sustainable development, as alternatives to reduce the negative impacts resulting from disorderly urban growth in the municipality of Itabuna-BA.

A new soil classification system for the quadrilátero ferrífero province using multivariate statistical analysis

2025-02-14T07:49:16-03:00

The Unified Soil Classification System (USCS) is widely used in geotechnical engineering, but it has limitations in classifying tropical soils due to characteristics such as the presence of saprolites or laterites. This study proposes a regional soil classification system for the mineral province of the Quadrilátero Ferrífero, in Brazil, aiming to enhance the understanding of soil behavior in the region. A total of 101 soil samples, both natural and compacted, were analyzed, including variables such as effective friction angle, cohesion, plasticity index, specific gravity of particles, and fines content. Principal Component Analysis (PCA) and k-means clustering were used to develop the proposed classification system. This categorizes the soils into three distinct classes (A, B, and C) based on their geotechnical parameters. The analysis showed that the proposed system outperforms the USCS in differentiating soil behavior in the Quadrilátero Ferrífero province, establishing a classification chart that explains 81.68% of the variability of the analyzed parameters. Compared to the USCS, the new system provides a more accurate tool for predicting soil behavior, being useful in foundation engineering, excavation projects, and other geotechnical applications in the region.

Determinação do índice de refração vertical, utilizando visadas reciprocas e simultâneas: análise de sua aplicação no cálculo do desnível utilizando nivelamento trigonométrico

2025-01-30T09:51:24-03:00

The safety and operational efficiency of dams are crucial aspects for their use. However, monitoring these structures faces several challenges. In the context of dam monitoring, the use of total stations has been a practice for controlling the movement of monitoring points. However, atmospheric refraction can introduce significant errors into the measurements performed, affecting the accuracy and reliability of the results. With this in mind, in this work a study was carried out at the hydroelectric power generation plant called Jaime Canet Junior, to analyze the effects of atmospheric refraction in determining unevenness, using data obtained by the first order geometric leveling method. Using the trigonometric leveling method equation, the value of the local refractive index was calculated, reciprocally and simultaneously, between three pillars located on the banks of the dam and in three different periods of the day. After this calculation, the behavior of the refractive index was analyzed, its relationship with local atmospheric conditions and the difference in level between pillars P1, P2 and P3 and two monitoring points located on the crest of the dam, called CG01 and CG02. Analyzing the unevenness values obtained through trigonometric leveling, using the calculated refractive index (k), in each period and for each line of sight, it is possible to see that the unevennesses show improvement in most cases compared to k = 0 ,13. However, this same behavior was not observed for the differences in level obtained from Pillar 3 (P3 – CG01; P3 – CG02), located downstream of the dam. It is estimated that this phenomenon occurred due to the high humidity in the area, due to fog, caused by the flow of water through the spillway, which had three gates open.

Análise da influência da sequência construtiva no desempenho de fundação por radiers estaqueados

2025-02-21T13:54:15-03:00

This article presents the analysis of the influence of constructive sequence on the performance of a foundation by raft piles of a building in concrete wall structure. The settlements were monitored in the field and estimated by the finite element method, with and without the consideration of soil-structure interaction (SSI) for the analysis of the redistributions of displacements and efforts in the foundation. The construction process was carried out in 4 stages per floor in a diagonal direction. The settlements in quadrant 1 were the largest, because of the partial execution of the building. In the last stage opposite quadrant 1, there were negative readings of settlements, which indicates lifting of the raft. Monitoring by stages showed the relation between the number of floors and SSI. With the increase in the stiffness of the structure, the maximum differential settlements reduced from 13 mm to the ground floor to 3 mm on the fifth floor. About 62% of the loads were transmitted to the piles and about 38% to the raft. The results showed the importance of a combined analysis of soil-structure interaction with consideration of the construction stage to understand the behavior of foundations by raft piles from a building in concrete wall structure.

Composição química e mineralógica de diferentes frações granulométricas dos finos de beneficiamento de rochas ornamentais

2025-01-10T08:51:59-03:00

The processing for dimension stone production generates a residue called Fines from Dimension Stone Processing – FIDSP. This material is considered a potential raw material for manufacturing "ecoproducts", motivating detailed studies of its composition. The aim of this work was to analyze the chemical and mineralogical characteristics of different particle size fractions of the FIDSP. Samples were analyzed for particle size fractions, chemical and mineralogical composition, the last two carried out after particle fractionation. Results show that the fraction passing the 0,053 mm aperture sieve had a relevant increasing in the loss on fire and in Ca an K contents, in addition to decrease in concentrations of Mg, Na, and Fe. Synthetic diamonds that can be reused were preserved in coarser fractions and it is necessary to control the entry of dirt that could worsen the quality of the FIDSP, if it is used as raw material.

Aspectos estruturais e geomorfológicos da bacia hidrográfica do Rio Bonito, Região de Caiapônia, Goiás, Brasil

2025-03-24T11:07:12-03:00

Abstract: The present research was conducted in the Bonito River Hydrographic Basin, located in the state of Goiás, Brazil, in the Cerrado Biome environment. The objective was to carry out an integrated characterization of the structural aspects of Geology, Landforms, and Pedology by preparing thematic maps, graphs, and tables, including a synthesis in all geomorphology units. The data were acquired in secondary vector data surveys processed with the support of QGIS 3.28 software, Firenze. The mapping detected geological, geomorphological, and pedological classes, with a significant presence of sedimentary rocks from Paleozoic formations, obtaining an important highlight, on the southwestern erosive edges of the basin, the Serra do Caiapó in the region under research, in the municipality of Caiapônia. Where it is shaped by landforms characterized by erosive, flattened, and weathered residues of sedimentary rocks, detecting a hypsometric amplitude of an average of 500 meters between the highest point upstream in the Serra do Caiapó to the mouth of the Bonito River. In conclusion, soil surveys demonstrate greater class extensions of Oxisols, favored by the pedogenic evolution of areas with smooth-undulating landforms.