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Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco 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.)

ABSTRACT The spatial variability of soil attributes in terraced areas is poorly studied in the semi-arid region. Considering that multivariate analysis enhances the diagnosis of spatial variability from geostatistics, soil attributes were studied in different zones between terrace channels in semi-arid region, more precisely in a retention terrace area in Canindé (Ceará, Brazil). Soil samples (n = 100) were collected at depths of 0.0 - 0.1 and 0.1 - 0.2 m for descriptive and geostatistical analysis. For multivariate analysis, samples from three zones relative to the terrace channel (Upper, Middle, and Lower) in the 0.0 - 0.2 m layer were considered, with 30 replicates. There was spatial dependence of soil attributes in the two layers studied. Near the channel, in the respective layers, there was higher clay content (13.7% and 14.7%) and higher degree of flocculation (61.3% and 71.7%) compared to the other zones. Water-dispersible clay was higher in the Upper zone (6.5% and 7.7% in the respective layers), while the Middle zone showed higher potential acidity in the evaluated layers (4.8 and 4.5 cmolc dm-3, respectively) compared to the other zones. In the multivariate analysis, there were highlights for the higher sum of bases in the Upper zone (18.9 ± 0.8 cmolc dm-3), higher sand content in the Middle zone (72.6 ± 0.6%), lower potential acidity (2.1 ± 0.2 cmolc dm-3) and higher phosphorus content (12.8 ± 3.0 mg kg-1) in the Low zone. The zone above the terrace channel loses mainly clay and requires practices to increase water and nutrient retention.

Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco 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.)

Accelerated erosive processes are global threats that can be quantified and classified. The northern region of Paraná is known for its high grain yield and crop rotation (soybeans, corn, wheat and oats). The municipality of Bela Vista do Paraíso has the particularity of being located on two geological formations, a basic eruptive of the Serra Geral Formation (JKsg) and a sandstone of the Adamantina Formation (Ka). The use of GIS to quantify soil loss has been intensifying in earth sciences, in which the GISus-M software is relevant for its practicality. It was observed that the C factors, which in this case have their values determined by the methodology of Durigon et al. (2014), are linked to monthly soil loss due to erosion due to crop rotation and their fallow period, in addition to erodibility (K factor) also having its significance, mainly associated with LS factors. The use of monthly modeling for RUSLE expresses a better observation of the erosive processes that occur, in addition to contributing to soil conservation measures and the planning and ordering of local roads in the municipality. Keywords: erosion; RUSLE; geological formations; GISus-M. [ABSTRACT FROM AUTHOR]

Lack of data regarding the agricultural activities in the area of Imués (Nariño, Colombia) has hindered understanding of current land uses and their impacts on natural resources, which causes this area to be considered one of the most arid in the region. To comprehend these processes, a description of the main land uses and agricultural and livestock production systems was made. This was carried out from a social, economic, and environmental dynamic through the characterization and typification of farms. Groups or clusters were constructed, which were previously subjected to qualitative statistical analysis, using the multiple correspondence factor analysis (MCAF) method. Subsequently, the hierarchical classification method was applied. The MCAF was able to establish four factors that were framed in the interaction of climate, altitude, and the productive component associated with it. Similarly, taking into account the social, economic, and environmental perspectives, it was determined that these groups, under their particularities and agricultural vocations, exert pressure on the territory's strategic ecosystems and diversity of flora and fauna. This makes their rural activities unsustainable. It was also found that there is a vocation for livestock exploitation and some minor species in the middle and high-altitude zones of the territory. However, it was established for other groupings that their major typologies were associated with conventional management without any planning. This generates negative impacts on soil resources, such as erosion and forest fragmentation, together with the expansion of the agricultural frontier.

Problems with soil erosion by water wind in the Brazilian Amazon are intensifying as the forest is replaced by agricultural production. Deforestation, burning, logging, and advancing the agricultural frontier have altered the soil-vegetation balance. In this context, the analysis of soil erosion susceptibility is one of the most significant challenges to developing long-term sustainability strategies and policies. Based on the above, the present study used the principles of Statistical Modeling - Logistic Regression - to develop and validate a model for analysis of susceptibility to soil erosion using 14 environmental factors. The study was carried out in a hydrographic sub-basin with 330 km2, located in the south of the State of Rondônia in the western Amazon, which combines characteristics of intense anthropic activity, loss of fertile soil, gullies, and silting of rivers. The study area has rainfall above 2000 mm year-1, they are transcurrent shear zones, predominant relief forms are flat to slightly convex tops, drainage networks are dendritic in an exorheic system, vegetation cover is composed of areas of forests and natural or regenerated forest fragments, agriculture is destined to annual crops. Livestock is extensive, with a predominance of small rural properties. The logistic regression model showed satisfactory results with an AUC of 0.888 and global accuracy was 0.77. The variables with the most significant effect on the equation were NDVI, erosivity, and TST. The mapping found that 57.71% of the study area is in places susceptible to soil loss due to water events.

Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco 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 present article presents the mapping of the landforms in the hydrographic sub-basin of the Jaibaras River, located in the state of Ceará, Brazil. To achieve this objective, the research methodology was based on Ross's taxonomic proposal (1992). However, this taxonomic proposal does not consider the semi-arid region, so adaptations had to be made using the classification of IBGE (2009) and Guimarães, Cordeiro, and Bueno (2017). Another objective, associated with the mapping, was to identify the soil erosion vulnerability index. For this stage, we used Crepani et al.'s methodology (2001). In the study area, we identified 3 morphostructural units, 3 morphosculptural units, 3 morphological units or patterns of similar forms, 5 units of landform types, and 3 slope units. In the 6th taxon, we identified natural erosive processes aggravated by human action and anthropogenic forms. As for the results of the erosion vulnerability mapping for the sub-basin, the morphosculptural unit of the Sertaneja Surface showed vulnerabilities ranging from moderately stable to moderately vulnerable. The morphosculptural unit of the Ibiapaba Sedimentary Plateau presented stable vulnerability, with prevailing pedogenesis. The morphosculptural unit of the Meruoca Residual Massif falls under the vulnerable classes, both in terms of incised valleys and steep slopes with sparse vegetation, young and shallow soils. [ABSTRACT FROM AUTHOR]

Sítio Laranjeiras, is part of the municipality of Quipapá PE, in this place, many years ago farmers explored the region, devastated the local forests, destroyed most of the native vegetation, today what remains of vegetation in this place is just a small forest, the farmers in that region were mostly people, people who didn’t even have elementary school, some knew how to write only their name, others not even that. Currently the correct management of the soil is studied by numerous scientists and scholars in the area of sustainability, these scholars and the like see every day more acting for a correct use of the soil. Looking for ways to plant and not cause so much erosion. Due to lack of important knowledge, the farmers in the studied area practically destroyed the soil, currently there are no more cassava crops and others that before were quite common in the place. [ABSTRACT FROM AUTHOR]

Copyright of Desenvolvimento e Meio Ambiente is the property of Universidade Federal do Parana 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 French-line Discourse Analysis (DA) and the Critical Discourse Analysis (CDA) support this study, which examines a journalistic statement about the effects of soil erosion on agricultural production. The intention is to investigate how a news about a typical problem in the rural and/or environmental universe produces meanings for interlocutors without links to agribusiness. The statement shows signs of polyphony, silencing and didacticity, which demarcate the conditions of text production, identify endo/exogroups, in addition to determining a line of reading, among many other possible ones. The analysis concludes that this discourse does not connect the problem of soil degradation to the final consumer. The meaning is interrupted in the rural production link, as if the effects of soil degradation suffered a discontinuity, without affecting items that are consumed by urban inhabitants. [ABSTRACT FROM AUTHOR]

Erosion is a serious environmental problem that affects Brazilian agricultural soils, mainly those with medium and sandy texture, naturally very susceptible to erosion, such as those occurring in the northwest of the state of Paraná, that have been potentially degraded, especially when cultivated with sugarcane. This work presents the survey of a characteristic slope and a typical pedological system of sandstones in the Santo Anastácio Formation, in the hydrographic basin of the Pirapó River. It studies the vertical and lateral transformations of the pedological horizons and its physical-hydric functioning, associating them with the use and management of sugarcane. The survey of the soils along the slope followed the Structural Analysis of Pedological Cover methodology. The physical, hydric, and chemical attributes of soils were determined in the pedological horizons identified in the trenches. The results pointed to a changing pedological system, where e-iluviation mechanisms and surface runoff act, enhanced by the management of sugarcane. The natural dynamics of the pedological system and the type of management adopted contribute to the installation and evolution of laminar and furrow erosion processes in the study area. [ABSTRACT FROM AUTHOR]

Pigg slurry (PS) is used as a fertilizer whose nutrients are lost through erosion and contaminate the environment if the manure is used inappropriately. The objective was to evaluate the effect of PS on soil and erosion, in a Alfisol soil. The treatments, 0; 50; 100; and 200 m³ ha-1 of PS were applied superficially after sowing once in each of the five crops, and in the straw of the last crop, totaling 0, 250, 500 and 1000 m³ ha-1, in oat (Avena strigosa), corn (Zea mays), turnip (Raphanus sativus L.) and soybean (Glycine max), and in oat residues. The simulated rain (65 mm h-1 and 75 minutes) was applied three times to corn and four times to turnip, soybeans, and residues, with a rotating arms simulator. Before and after the research, the content of K, Ca and Mg in the soil was determined. The rainfall applied at each moment made up a test (T). T1 occurred after the application of the PS and the other tests at intervals that varied between 14 and 70 days, depending on the weather. During the runoff, at five-minute intervals, runoff samples were collected to determine water losses and the content of K, Ca and Mg in the water. The PS did not influence the nutrient content in the soil. The content and total losses of nutrients were higher with 1000 m³ ha-1 of PS than in the absence of manure. With the increase in runoff, the content in the runoff decreased and the total loss increased, which also increased with the increase in the nutrient content in the runoff. It is recommended to apply less than 500 m³ ha-1 of total PS in the soil, even in interval applications, due to the high loss of K, Ca and Mg by water erosion. [ABSTRACT FROM AUTHOR]

Copyright of Labor & Engenho is the property of Universidade Estadual de Campinas - Portal de Periodicos Eletronicos Cientificos 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 cultivation of vegetables in general degrades the soil because it is necessary to adopt intensive mechanical preparation operations. The objective of this research was to quantify soil losses (SL) and water losses (WL) by water erosion in the onion cycle in different types of soil and crop residue management, under simulated rainfall conditions, in 2017. No-tillage treatments were studied: 1) furrows in the planting line on the corn residue (NTC); 2) furrows in the planting line over the soybean residue (NTS); 3) soil preparation with a plow + two harrowing + manual rake on the corn residue (SPC); 4) soil preparation with a plow + two harrowing + manual rake on the soybean residue (SPS); 5) soil preparation with one plowing + two harrowing + manual rake without cultivation and uncovered (BS - control). Four simulated rains were applied to the treatments, each lasting 60 min and 65 mm h-1 of constant intensity, with a rain simulator with rotating arms of the thrust type. The total soil losses observed at the end of the four simulated rainfall applied in the treatments NTC, NTS, SPC, and SPS were respectively 1.35; 3.35; 7.36; 33.72; and 55.44 t ha-1. Soil losses verified in the NTC, NTS and SPC treatments were respectively 85%, 63% and 12% lower than the soil loss tolerance of 9 t ha-1 year-1 The increase in soil cover by crop residues caused an exponential decrease in soil losses, while these losses increased exponentially with the increase in runoff velocity. Runoff water losses showed the same trend as soil losses, but with less dependence on soil management. [ABSTRACT FROM AUTHOR]

In the Northern Cerrado, increasing pressure from Society on Nature has intensified existing problems, such as the loss of soil in productive areas. This article evaluates the spatial and temporal variability of soil loss in the periurban area of São Desidério (BA), one of the largest grain producers in the country, and its relationship with the land tenure structure and the consolidation of agribusiness in the region. For this purpose, the Revised Universal Land Loss Equation – RUSLE – was calculated for the years 1990, 2000, 2010 and 2020, for each rural property, classified by rural module size. Small properties have higher soil loss rates, followed by micro, medium and large properties. During the period, there was a general trend towards an increase in soil loss around 50%. The micro and small properties had average rates twice as high compared to the medium and large ones, showing the need to improve soil management practices. [ABSTRACT FROM AUTHOR]

Piracicaba river basin, located in the central-eastern region of Minas Gerais, owns one of the largest and most importante remnants of Atlantic Forest biome in this State. Despite that, environmental pressures created by several economic activities, specially mining, are observed. To understand specificities of regional environmental dynamics could support the creation of more effective public policies for its conservation challenges. The main goal of this study is to identify vulnerable areas to soil loss in Piracicaba river basin, in order to support actions to mitigate environmental impacts and other socio-environmental processes. Specific goals are: to annalyze the role of every environmental component in the vulnerability generated map; to integrate the variables of the physical environment which directly influences the soil loss: climate, geology, soils, geomorphology and use and occupation. The integration of those variables was done by using the environmental vulnerability model of the basic territorial units proposed by Crepani et al. (2001). The results obtained in the model shows that, the southern region of the Piracicaba River basin, located in the edge of Quadrilátero Ferrífero, is more vulnerable to soil loss. The most stable areas are located in the northwest region of the basin. [ABSTRACT FROM AUTHOR]

Water erosion of soil slopes causes several environmental, economic, and social losses worldwide every year, particularly, when it reaches more advanced stages, leading to the formation of gullies. The municipality of Alegre, in the state of Espírito Santo (southeastern Brazil), has numerous gullies, which stand out in the landscape by their impressive proportions and environmental impacts. Nevertheless, very few studies have been published on the subject and most focus on specific erosion features. Therefore, this study aimed at mapping out the gullies to create an inventory and at qualitatively evaluating the environmental factors controlling gully development from 2009 to 2019. Terrain elevation, slope angle, aspect, surface curvature, lithology, soil types, rainfall erosivity, and land cover were considered gully causative factors. Google Earth Pro imagery and classical Geographic Information System (GIS) techniques were used to locate the gullies and to process/evaluate the environmental factors. The number of gullies in the study area remained approximately constant over the past ten years. Results revealed that the gullies may have started at different periods and are still active and evolving. Finally, the spatial distribution of the gullies is not random, but controlled by geomorphological, geological, and land cover factors.

Copyright of Nativa is the property of Revista Nativa 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.)

Soil losses due to water erosion have impacts in the Western Plateau of São Paulo, whose changes in the land cover of the hydrographic basins can intensify these conditions of soil degradation. This article aims to analyze the land cover changes in the basin of Confusão's stream and relate to the parameters of the factors of the Universal Soil Loss Equation. The land cover charts were generated with data from satellite CBERS images dated 2009 and 2018, by supervised classification, in GIS. The areas of the land cover classes were related to factor C of the USLE and data estimates of secondary sources of erosivity (R), erodibility (K) and topographic factor with the data of slope (LS). From these parameters, an estimate of soil loss was presented for the basin of Confusão's stream. The soil loss in the basin of Confusão's stream was estimated by 2018 data at 2,484 t/ha/y. [ABSTRACT FROM AUTHOR]

The approach to the soil theme highlights its importance for life and the need for its conservation. This article is the result of reflections developed in the classroom, in the subject of Geography, with the participation of Elementary School II students in the context of the Solo Project at the School of the Department of Geographical Sciences at the Federal University of Pernambuco - UFPE. The study had 6th grade students from a public school as its target audience. The proposal was based on a pedagogical action with the objective of discussing the importance of conservation of the environment within a culture of sustainability, working with the theme of soil erosion. Through the reflections carried out in the Geography discipline, we sought to reflect on the students' conceptions and learning about sustainability and the environment. The methodology was carried out through the preparation of didactic material called erosion simulator, which was used to carry out a practical activity in the classroom, with the theme of soil erosion. This pedagogical intervention contributed to changing the students' perspective in relation to the spaces studied and, thus, they were able to see new perspectives and possibilities for soil conservation, in addition to giving new meaning to the teaching-learning process. [ABSTRACT FROM AUTHOR]

The costs for carrying out representative and accurate measurements, in situ, for estimating laminar water erosion in large areas are quite expensive. The work aimed to spatialize and analyze the soil erosive susceptibility of the Dourados Watershed qualitatively through the application of USLE/RUSLE and free geotechnologies. It can be observed that 46,2% of the Dourados river watershed presents a soil loss of fewer than 10 tons/ha. Per year. Regions with exposed soil, land use, and occupation with agricultural predominance along with soil factors with higher erodibility and specific topography (larger slopes) lead to large annual losses of soil (> 150 ton/ha.year) in 2,4% of the watershed. [ABSTRACT FROM AUTHOR]

The culture of cover crops in the off-season or in crop rotation may be a strategy to improve the physical, chemical and biological characteristics of the soil and prevent erosion processes. Several grass and leguminous species may be employed for such end. Each has a peculiar dynamic with regard to cover speed and persistence in the soil. The dynamics of cover rates and decomposition of cover crops and the effect of the species' root system on the soil's physical features are analyzed. Assay design was totally randomized, with eleven treatments and four replications, with cover crop species Brachiaria brizantha Hochst. (Stapf), Crotalaria bleviflora, Crotalaria juncea, Crotalaria ochroleuca, Stylosanthes capitata + Stylosanthes macrocephala, Canavalia ensiformis, Cajanus cajan cv. IAC/Fava-larga, Cajanus cajan cv. IAPAR 43, Pennisetum glaucum, Mucuna cinereum and Mucuna aterrima. Soil cover rates were evaluated at 20, 40, 60 and 80 days after seeding. Decomposition rates of vegetal wastes were analyzed at 15-day regular intervals as from the cutting of the crop. Canavalia ensiformis, Mucuna cinereum and Mucuna aterrima covered the soil totally after eighty days of seeding and Pennisetum glaucum had the greatest resistance after sixty days from cutting. [ABSTRACT FROM AUTHOR]

Copyright of Revista IRRIGA - Brazilian Journal of Irrigation & Drainage is the property of Revista IRRIGA (Brazilian Journal of Irrigation & Drainage) 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.)

In environmental management, soil erosion is one of the recurrent problems, which presupposes planning land use according to its potentialities and limitations. This study had as objective to determine the potential of laminar erosion (estimated annual soil loss) for the São Francisco Falso River Basin (SFFRB) and São Francisco Verdadeiro River Basin (SFVRB), located in the western region of the State of Paraná (Brazil), through the spatialization of the Universal Soil Loss Equation (USLE), from map algebra using the Software QGis. The Soil Loss Tolerance (T) map was also elaborated. From the spatialization of USLE it was found that most of the area under study (56.58%) was concentrated in a low estimate range of annual soil loss (0 to 2,5 t ha-1 year-1). Regions of high slope, where the terrain is less dissected and the Latosols predominate, presented lower values for estimating annual soil loss (0 to 10,00 t ha-1 year-1), while in the medium and low slope regions, where there is a predominance of Nitosol soils and greater dissection of the tarrain, higher values were found (10,00 to 50,00 t ha-1 year-1 or > 50,00 t ha-1 year-1). Fractions of 15,68% and 18,27% of SFVRB and SFFRB areas, respectively, presented annual soil loss estimated values higher than their respective loss tolerance. [ABSTRACT FROM AUTHOR]

The process of land use and occupation in the Cerrado caused major changes in the environmental balance of the biome, reflected in the form of various environmental impacts. Among these is the loss of soils through erosion. Despite the fact that large portions of native vegetation are still recognized, when compared to the rest of the state, the micro-region of Vai do Paranã in Goiás has unique physical attributes, which makes it the scene of major degradation when it is associated with human misuse. With the intention of using the methodology of the Universal Soil Loss Equation - USLE to estimate annual soil loss in the São Domingos and Corrente river basins, in the Vai do Paranã, the attributes of hypsometry, slope, land use and its cover in the years 1985 and 2015. I was observed at this stage a greater concentration of attributes that expressed environmental vulnerability in the São Domingos river basin, which was also foud in the analysis of morphometric parameters, and with the application of the USLE, since it presented (although small) a higher estimate of annual soil loss, compared to the Corrente river basin. This fact may possibly be related to the presence of Conservation Units, which should minimize the advance of anthropization and its possible environmental impacts in the region. [ABSTRACT FROM AUTHOR]

The use and occupation of the soil is a preponderant factor for the attenuation or intensification of erosive processes, since areas that have an adequate soil cover present less potential to produce sediments. Thus, the present work aims to carry out an analysis of soil losses in the Rio de Janeiro Basin (Western Bahia Region) for different conditions of land use and occupation, using USLE in a GIS environment. In which it was found that the Rio de Janeiro Basin has undergone an intense change in its use and land occupation in the last 40 years, with suppression of about 54% of the area of native vegetation, which significantly influenced the increase soil losses in the basin. The western portion of the basin was more susceptible to soil losses due to the higher concentration of the dryland farming class. In contrast, the eastern region of the basin showed the lowest values of soil losses due to the predominance of native vegetation, thus showing its effectiveness in mitigating erosion processes. [ABSTRACT FROM AUTHOR]

The cover crop on the soil surface is a fundamental practice for the establishment of soil and water conservation systems. The Santa Fé System consists of the inclusion of forage species in the grain production system, mainly by intercropping. The objective of the study was to evaluate the effect of cultivation of single maize and maize in consortium with U. brizantha cv. marandu, in runoff and quality of runoff using a rainfall simulator. The experiment was carried out at the School Farm of the IF Goiano Campus Iporá in a Quartzipsament, in a Brazilian Savanna region. The following land cover were evaluated: uncovered soil, single hybrid corn and Santa Fé System. For the determination of the runoff volume and the runoff quality, three tests were performed in each treatment, using a pendulum rainfall simulator built at the IF Goiano Campus Iporá. In each test, the total volume of runoff was counted and every five minutes samples were collected to characterize the runoff quality, in which turbidity, pH and electrical conductivity were analyzed. Water losses were reduced by 82% and turbidity by 96% in the Santa Fé system, compared to uncovered soil. The Santa Fé System showed better performance with less runoff volume and better quality of runoff when turbidity was evaluated, which demonstrates its high potential in minimizing soil water erosion. [ABSTRACT FROM AUTHOR]

The mapping of coverage and land use are cartographic products used in several surveys, as they serve as bases for hydrological models, models of future scenarios, of soil losses, among others. Thus, in view of the importance of land cover mapping, the article aims to present a case study to highlight criticism and selfcriticism of the work carried out. The methodology used was the classic one, involving digital image processing in a geographic information system environment. The results revealed that the presence of federal conservation units and indigenous lands contributed to 64.03% of the mapped area being covered by the Natural Vegetation - Forestry class. The antrópica area use class, consisting of the most recurrent agricultural and grazing activities, occupies 17,26% of the municipality of Porto Velho. [ABSTRACT FROM AUTHOR]

Copyright of Geosaberes: Revista de Estudos Geoeducacionais is the property of GEOSABERES - Revista de Estudos Geoducacionais 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.)

Determining the origin of eroded soil is essential to design effective soil erosion control strategies which preserve the soil resource, enhance agricultural productivity, and reduce the negative impacts of soil erosion, in-field and off-field. Magnetic properties have been widely used in temperate environments to identify sediment sources, pathways and links, but there have been very few applications in tropical and subtropical environments. Therefore, in this paper we investigated reservoir sediment sources in the Upper Grande River Basin, Southeastern Brazil, using sediment tracing techniques based on magnetic parameters (low and high frequency magnetic susceptibility, frequency dependent susceptibility). The different parent materials and subtropical weathering conditions resulted in soils having different Fe oxide minerals and Fe oxide contents, promoting magnetic variability that allowed comparison and identification of possible sources of reservoir sediments in order to reduce water erosion impacts. The results indicate the suitability of magnetic properties as a tracer for soil erosion studies in tropical environments.

In 1965, the USLE (Universal Soil Loss Equation) model was created, which aims to predict the erosion that will occur in a given area, serving as a method to assist in decision making on soil use and management. The model lists six factors, among them that of rain erosivity (R), which has been the most used for the analysis of water erosion, precisely because it collaborates in projects for more efficient sizing of hydraulic works. Thus, the objective was to estimate the value of the Factor R for Marudá (PA) making the data serve as a basis for the nearby municipalities, given the scarcity of more up-to-date information. The period from 1994 to 2019 was used, and the return period and the probability of erosive rains were also calculated. The monthly rainfall erosivity was quite variable, with values ranging from 11.97 a 391.77 MJ mm ha-1 h-1 month-1. Annual erosivity ranged from 1,169.95 (in 1998) to 2,481.17 MJ mm ha-1 h-1 year-1 (in 2009). The value of the R Factor for Marudá is 1,831.92 MJ mm ha-1 h-1 year-1. The highest annual value had an estimated payback period of 27 years with a probability of 3.7%. All information obtained in the study can be used safely for nearby locations and with similar climatic characteristics, which extends the possibility of using the Universal Soil Loss Equation in planning both agricultural and urban activities. [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.)

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.)

Laminar erosion is considered one of the main causes of soil degradation, which results in the loss of soil nutrients and damage to agricultural activities, in addition to polluting and silting up the watercourses of its hydrographic network. Human activity is primarily responsible for the acceleration of this natural process, for the use of land use. To elaborate an adequate environmental planning, it is necessary to diagnose the amount of eroded soil and the places where the loss of sediment is greater. To this end, this article uses the Universal Soil Loss Equation (EUPS) and the Sediment Production Ratio (RPS) in the first order hydrographic basin of the Zaúna stream, in the municipality of Maringá - PR, in order to identify the amount of sediment available, transported and retained. The analyzed period was between the months of July 2016 and June 2017. The results showed smaller amounts of eroded material in the area, with greater emphasis on the classes between 0-3 and 3-5 (ton.saz), separated in seasonal calculations. (4) and annual (2), one considering the exposed soil and the covered soil). The greatest losses of soil in the watershed occurred in the spring season and in the annual calculation of soil exposure. [ABSTRACT FROM AUTHOR]

One of the most important environmental impacts from tourism in protected areas is erosion and soil loss, which is related to pluviosity and to the local trail grades. In the present work we have developed a methodology using geoprocessing tools to estimate the trail grades of Tijuca National Park and we relate this information with possible impacts on soil erosion and the with difficulty classification system of the Park's trails. Our results show that the trails of Tijuca National Park have in general grades far superior to what the literature considers sustainable. Our data also showed that the trail difficulty classes, contrary to what would be expected, do not correlate with trail grades. [ABSTRACT FROM AUTHOR]

The fundamental condition for the management of water catchment watersheds is to know their physical characteristics among them are slope, land use and land cover, and soil loss. Knowing them makes possible the planning and taking actions that guarantee not only quality and availability of water use, but also an environmental sanity and local ecological balance. In this context, the objective of the study is to analyze and characterize the Socorro River watershed, located at northeast of Rio Grande do Sul, focusing on slope, clinography, soil use and land cover, and local soil loss. Thereunto, there were used geographic information systems (GIS), cartographic data, such as hydrography and contour and data coming from remote sensors aim to generate slope, land use and land cover and soil loss maps. The obtained results indicate that the watershed is mostly flat and slightly wavy. Related to the soil loss at the watershed, approximately 90% of its areas were classified as the least susceptible class. About the land use and land cover, stands out the anthropic occupation of agriculture (258.62 km², 49.10%) replacing the native vegetation, considering that the last one occupies a representative area at watershed’s outfall (244.24 km², 46.37%). These data serve as base for depth works in the area and for the management of the watershed. [ABSTRACT FROM AUTHOR]

Soil is a very important natural resource for life on earth, having an important ecological role, being the main substrate for the development of plants, living in it several animals. The development of experiments on soil erosion are shown as important didactic-pedagogical resources to work the consequences caused by the natural and mainly anthropic action on the soil, in the approaches of the discipline of Geography that studies the various relationships between man and the environment. In view of this understanding, the objective proposed here is to analyze the importance of using soil practices as a methodological resource for the development of an environmental awareness and a better teaching and learning process by students. The activities were developed during the Pedagogical Residence of Geography of the State University of Paraíba, with students of the 8th year of the Municipal School Judith Barbosa de Paula Rêgo, located in the municipality of Queimadas, in the state of Paraíba. [ABSTRACT FROM AUTHOR]

The erosive processes, results of some physical phenomena, in many cases related to the human activities, cause soil loss and create an environmental vulnerability with loss of soil stability and fertility, negatively affecting the economy and the society. In order to mitigate and, when possible, to prevent the erosive processes, it is necessary, the knowledge of the physical and historical characteristics of the area. Therefore, in view of approval of the first Área de Proteção Ambiental, located in Bairro do Timburi, municipality of Presidente Prudente (SP), this assignment aimed to analyze the occurrence of erosion processes linear, and their geomorphological conditions. In this regard, several thematic maps were drawn up, having as a central point the forms of relief, and carrying out fieldwork to identify the areas most vulnerable to the development of erosion processes. As a result, it was identified that, of the 78 linear erosive features mapped, 48 (61.54%) are in concave slopes; 33 (42.3%) on a slope of 5- 10%; and 55 (70.51%) related to agricultural anthropic areas. [ABSTRACT FROM AUTHOR]

So that one may obtain the economic value of an environmental resource, its monetary value should be estimated in relation to other goods/services available in the economy. Environmental valorization methods currently used are relatively new and the variables in the process may not be known or partially known. One method is the Reposition Cost that calculates the value of reparation from a damage. Current paper applied the reposition cost method in the economic valorization of nutrient loss by soil erosion in the hydrographic basin of the river Una, Brazil, through geoprocessing to evaluate spatially the area under analysis. Thirty-five samples were collected and the soil´s nutrients quantified, Ca, Mg, P and K. Concentrations were spatialized and annual loss estimated, with reposition costs. In more than 89% of the studied area, the reposition cost of K, P, Ca and Mg of the three fertilizers employed (potassium chloride, potassium chlorate, simple superphosphate and lime) reached about R$ 0.01 per m². Total reposition cost was R$ 352,846.43. The spatialization of reposition costs showed which areas required special attention of the government with regard to monitoring and proposition of sustainability. [ABSTRACT FROM AUTHOR]

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Soil degradation is a physical process intensified by political and socioeconomic factors, and by the population growth of the 20th century. In this study, we evaluated the sediments of the Frutal and Bebedouro Streams, located in Frutal municipality, Minas Gerais State, Brazil, and their relation to major human activities that are responsible soil erosion and silting. Samples were collected between 2012 and 2013 for the determination of granulometric composition, organic matter content, and minerals in sediments. The Wentworth scale was used for particle size measurement, and then the size classes regrouped to ABNT scale (NBR 6502/1995). The results found that agriculture and cattle ranching are the main activities that cause intense erosion and silting in both watersheds. Bebedouro Stream is better preserved, as it is completely located in rural area with larger riparian vegetation, unlike the mid-stretch of Frutal Stream, which is located in an urban area. Quartz is the predominant mineral in the sediments as the soils of the region are formed by sandstones; consequently, few nutritional elements were found in the studied samples. Principal component analysis showed that water quality parameters are correlated to silt/clays and organic matter content in most of the collected stations.

Soil erosion is one of the greatest environmental problems of our time. Every year millions of tons of arable land are lost through this process, contributing to the loss of soil fertility and to the decrease of crop productivity. Rain erosivity is described as an interaction between the kinetic energy of the raindrops and the soil surface, representing the potential of rainfall and flooding in soil erosion production, thus exerting a great influence on erosion, especially in tropical environments. In this context, the present work aims to determine the spatio-temporal variation of rainfall erosivity in the Araçuaí river basin - MG. Precipitation data of 14 rainfall stations distributed in the basin territory, containing uninterrupted historical series from 1996 to 2015, were selected. From the historical series, the Fournier Modified Index (MFI), the average monthly erosivity (EI30m) and the Annual Average Erosivity (R-Factor) were calculated for each rainfall season. The data were interpolated for the entire basin by the inverse method of Distance (IDW). The results indicate an annual mean erosivity in the basin of 9125 MJ mm ha-1 h-1 year-1. The spatial analysis indicated the existence of a decreasing gradient of erosivity in the South-North direction, with the highest values in the upper reaches of the basin. The temporal analysis showed that the highest values of erosivity occurred in the period from October to March, and the lowest values from April to September. [ABSTRACT FROM AUTHOR]

Conservation management systems that have the intention of avoiding soil erosion or degradation have been diffused in agriculture. Among these systems is the no-tillage system. The present work was carried out with the objective of evaluating the effect of limestone and agricultural gypsum application on the cultivation of soybean grown in the no-tillage system. The experimental design was a randomized block with four treatments (T1 - limestone and agricultural gypsum application to establish that, respectively, calcium occupy 70% of the CTC in the 0-0.20 and 60% of the CTCe layer in the 0.20-0.40 m layer - T2 - limestone and agricultural gypsum application to establish that calcium occupies 52.5% of the CTC in the layer of 0-0,20 m and 45% of the CTCe in the layer of 0,20- 0,40 m; T3 - limestone and agricultural gypsum to establish that calcium occupies 35% of the CTC in the 0-0.20 m layer and 30% of the CTCe in the 0.20-0.40 m layer, T4 - standard treatment, without application of limestone and agricultural gypsum) and four replicates. The parameters evaluated in the soybean crop were: height of insertion of the first pod, height of plants, final stand ha-1, mass of one hundred grains and grain productivity ha-1. The data were submitted to the F test and the means were compared by the Tukey test (p <0.05). It was verified that the treatment T2 presented higher height of insertion of the first pod than the standard treatment. For the other evaluated agronomic characteristics, there was no difference between treatments. [ABSTRACT FROM AUTHOR]

The soil erosion has been known for a long time as a serious environmental problem, especially in the areas with anthropic action and agricultural management without adequate criteria. This work applies the RUSLE empirical model to the estimation of the annual soil loss in the Marinheiro Creek watershed, Sete Lagoas - MG (Brazil). The results of the annual soil loss in the Marinheiro Creek watershed are 7.15 ton. ha-1.year-1in average. It was also possible to classify and to characterize the results in six classes, 0 to 1 (very low); 1 to 3 (low); 3 to 5 (moderate); 5 to 10 (severe); 10 to 20 (high); and above 20 ton. ha-1. year-1 (very high). The dominant classes are the low and very low classes (61.7%). Nevertheless, 21% of the area present environmental risks associated to the severe to very high classes, which are subjected to enhanced erosion processes. It was noted that, accordingly to the model, the annual soil losses were higher in the areas under use. The methods presented here allowed the understanding of the relation of the erosion and its causes, being useful for the planning and the implementation of the management practices for soil and water conservation. [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.)

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.)

RESUMO O presente estudo trata sobre a ocorrência de processos erosivos acelerados em áreas de extração de agregados da construção civil (areia e cascalho), localizados nas proximidades dos rios Canavieiras e Itapicuruzinho, afluentes do rio ltapicuru-mirim, no município de Jacobina (BA). A área estudada possui 10,8 km² e mantém o processo de extração desde a década de 70, sendo favorecida pela grande ocorrência de reservas minerais em toda planície fluvial e em encostas próximas ao leito do rio. Neste contexto, foram levantadas e estudadas as causas da grande ocorrência de feições erosivas em torno das áreas de extração, sendo feita a caracterização morfológica, granulométrica e do teor de matéria orgânica em dois perfis de solo. Foram realizadas medições em uma voçoroca localizada na área de estudo, sendo traçado um perfil tridimensional para ser calculado o volume de sedimentos que saiu da mesma. Além disso, foi realizado o mapeamento da rota dos sedimentos erodidos com auxílio de GPS e Imagens de Satélite. A partir dos resultados das análises no perfil do solo foi possível verificar a alta vulnerabilidade dos solos aos agentes erosivos, comprovados pelo baixo conteúdo de matéria orgânica, pela textura com altas concentrações de areia, silte e baixas de argila, e também pela natureza da estrutura apresentada pelos agregados. Foi verificado ainda, através do monitoramento da rota de sedimentos erodidos, que estes têm como destino a lagoa Antônio Teixeira Sobrinho, os rios Canavieiras e Itapicuruzinho, potencializando o assoreamento dos mesmos. Palavras-chave: Erosão de Solos; Voçorocas; Agregados da Construção Civil. THE ACCELERATED EROSION PROCESSES IN AREAS OF AGGREGATES EXTRACTION OF CIVIL CONSTRUCTION IN THE TOWN OF JACOBINA - BAHIA ABSTRACT This paper presents a study based on the occurrence of accelerated erosion in extraction areas of aggregates of the building (sand and gravel), it is located near the Canavieiras and Itapicuruzinho rivers, affluents of ltapicuru-Mirim river, in the town Jacobina (BA). The studied area has 10.8 km² and maintains the extraction process since the 70s, being favored by the occurrence of large mineral reserves across fluvial plain, and near the riverbed slopes. In this context, were raised and studied the causes of the high occurrence of erosional features (gullies and ravines), around areas of extraction, being taken the morphological, physical and chemical research of two soil profiles. Were realized also performed on the main gully located in the study area, being planned a three-dimensional profile for calculate the volume of sediments that came out of the same. Furthermore, it was performed the mapping of the route of eroded sediments with the aid of a GPS and Satellite Images. From the results of the chemical, physical analyses, and morphological characterization, was observed the high vulnerability of soils to erosive agents, proven by the low organic matter content, the texture with high concentrations of sand and silt, and low concentration of clay and also by the nature of the structure presented by the aggregates. It was also verified by monitoring the route of eroded sediments that goes to the Antonio Teixeira Sobrinho lagoon, and the Canavieiras and Itapicuruzinho rivers, enhancing the silting up of the same. Keywords: Soil Erosion; Gullies; Construction Aggregates. PROCESOS EROSIVOS ACELERADOS EN LAS ZONAS DE EXTRACCION DE LOS AGREGADOS DE CONSTRUCCIÓN CIVIL EN LA CIUDAD DE JACOBINA – BAHIA RESUMEN Este presente trabajo se refiere a la aparición de la aceleración de la erosión en las zonas de extracción de agregados de construcción (arena y grava), situada cerca de los ríos Canavieiras y Itapicuruzinho, afluentes del río ltapicuru-Mirim en la ciudad de Jacobina (BA). El área de estudio tiene 10,8 km² y está en el proceso de extracción desde los años 70, siendo favorecido por la alta incidencia de las reservas minerales de toda llanura fluvial y laderas cercanas al lecho del río. En este contexto, el presente trabajo de investigación se desarrolló sobre las causas de la alta incidencia de rasgos erosivos (voçorocas y ravinas o barrancos), alrededor de las zonas mineras, e hizo la caracterización morfológica, física y química de los dos perfiles de suelo. Las mediciones se realizaron en la “voçorocas” principal, ubicada en el área de estudio, a través de un perfil tridimensional para calcular el volumen de sedimentos que salió de ella. Además, la asignación se realizó en la ruta de los sedimentos erosionados utilizando GPS y las imágenes de satélite. De los resultados de la caracterización química, física y morfológica se observó la alta vulnerabilidad de los suelos a los agentes erosivos, demostrado por el bajo contenido de materia orgánica, la textura con altas concentraciones de arena, silte y arcilla de baja, también la naturaleza de la estructura presentada. Se encontró también mediante el control de la ruta de los sedimentos erosionados, sus desplazamientos, se están moviendo a la laguna Antonio Sobrinho Teixeira, los ríos Canavieiras y Itapicuruzinho, causando el aterramiento de los mismos. Palabras clave: La Erosión del Suelo; Las Voçorocas; Los Agregados de Construcción.

ABSTRACT Several Sediment Delivery Ratio (SDR) models have been used to estimate Sediment Yield (SY), mainly in data-scarce and ungauged basins, such as in many regions of Brazil. However, it is difficult to choose the most suitable SDR model, mainly because of the lack of investigations of this approach using observed data. Here, we investigated the performance of five widely used SDR models (SDREST) to estimate sediment yield values (SYEST ) based on observed data in a tropical watershed. We used observed sediment yield values (SY OBS) during September 2011 to July 2017 in three sub-basins of the Guariroba Basin, Midwestern Brazil. To estimate the average annual soil loss, we used the Revised Universal Soil Loss Equation. The SDROBS and SYOBS ranged from 5.56 to 10.54% and 940.76 to 5,400.32 t yr-1, respectively. The Williams and Berndt (1972) method presented the best performance, with a percent bias ranging from -2.34 to 3.30% in SRD estimation. Therefore, this model provided suitable SDR and SY estimates, and may be useful to estimate SY in other tropical data-scarce and ungauged basins.