A erosão em estradas não pavimentadas associada ao escoamento superficial gera grande impacto ambiental, sendo a principal causa de inundação, contaminação da água e alteração da fauna aquatica, entre outros, tornando-se necessário desenvolver estratégias de prevenção e controle. Para isto, a obtenção de valores confiáveis dos índices de resistência do solo ao processo erosivo é premente; sentido em que este trabalho teve, como objetivo, determinar os índices de erodibilidade e a tensão crítica de cisalhamento em canal de drenagem construído em uma estrada não pavimentada implantada em um Latossolo Vermelho-Amarelo. O estudo foi realizado em uma estrada não pavimentada do município de Viçosa, MG, que apresentava problemas de erosao utilizando-se um simulador de escoamento para determinação direta no campo. Os dados de erodibilidade e tensão crítica de cisalhamento foram obtidos com base na técnica de identidade de modelos. O valor de erodibilidade determinado foi de 0,0044 g cm-2 min-1 Pa-1, ao qual foi associado um intervalo de confiança com 95% de probabilidade de 0,0035 a 0,0053 g cm-2 min-1 Pa-1. A tensão crítica de cisalhamento obtida foi de 7,61 Pa.

Through this research, the objective was the use of geoprocessing to characterize the areas of implementation of dams distributed in areas with agricultural uses, in addition to evaluating the perception of producers regarding the supply of water. The geographic coordinates (vector points) of dam construction sites on rural properties in the municipalities of Corumbá de Goiás, Abadiânia, Alexânia and Silvânia, GO were used. The characterization of these little dams, and their area of influence, was applied by geoprocessing techniques with products such as: land use and cover, soil classes, hypsometry and terrain slope. All information was entered and analyzed using the QGIS 3.10 software. To assess the perception of producers regarding the supply of water in springs and the dry period, a questionnaire was applied. The installation of dams has been distributed in areas with steep slope of the land, ramp length less than 100m (in most properties), the largest number of dams implemented were in areas with greater slope and ramp length, and soils of the class of Oxisols. The use of satellite images, morphometric products, and geoprocessing techniques indicates the potential use of these tools for application in soil and water conservation areas. According to the producers, the barraginhas provide benefits for agriculture by increasing the supply of water in source of the river and in periods of drought in local rivers.

The aim of this study is the macroscopic environmental assessment of the springs and their permanent preservation areas and the bed located in the basin of the Corrente do Matões stream. The study was conducted in the basin of the Corrente dos Matões stream, where field trips were carried out in order to assess the vegetation, environmental impacts, geological aspects, characterization of the permanent preservation area associated with the spring, direct access to animals, presence of household waste in the springs and surroundings, constructions, water collection, multiple uses, proximity to impacting activities, in addition to other aspects that were noted and recorded with a camera and a GPS. Collections of water samples were also carried out to assess the concentration of some chemical elements. In view of the analysis of this study, it was registered that the Riacho Corrente dos Matões has five springs, being fed only by three. The study also revealed that, depending on the use of the land, the impacts are different in the basin of the Corrente dos Matões stream and that, even though it is a river located in the rural area, it suffers pressure with the advance of urbanization.

Objective of the work was to perform the spatialization of the monthly and annual erosivity of the hydrographic basin of Córrego Fundo, Aquidauana-MS, through the use of a Geographic Information Systems. For the characterization of rainfall and erosivity, historical series of 28 years were considered, corresponding to the years 1991-2019 of 5 weather stations belonging to the hydrometeorological network of the National Agency and 1 station of CEMTEC / MS - in the period 2008-2018. The erosivity determination was made according to the potential equation adjusted for the municipality of Campo-Grande, MS and later spatialized for the entire basin, using ArcGis PRO 2.5.2 software. The average annual erosivity ranged from 7749.29 to 7800.55 MJ mm ha-1 h-1 year, with an average erosivity of 7,781 MJ mm ha-1 h-1 year. The months of greatest erosivity are related to the rainy periods in the region. Some months of the year, monthly erosivity was rated very low to low, however the average annual erosivity was considered high. The results of this work present relevant information to support the planning of soil and water conservation, as it was possible to verify, throughout the year, the months that present the greatest susceptibility to erosion.

The Jaguarí River Basin forms the main water supply sources for the São Paulo Metropolitan Region and other cities in the state. Since the kinetic energy of rainfall is the driving force of water erosion, the main cause of land and water degradation, we tested the hypothesis of correlation between the erosive potential of rainfall (erosivity) and geographical coordinates and altitude for the purpose of predicting the spatial and temporal distribution of the rainfall erosivity index (EI30) in the basin. An equation was used to estimate the (EI30) in accordance with the average monthly and total annual rainfall at rainfall stations with data available for the study area. In the regression kriging technique, the deterministic part was modeled using multiple linear regression between the dependent variable (EI30) and environmental predictor variables: latitude, longitude, and altitude. From the result of equations and the maps generated, a direct correlation between erosivity and altitude could be observed. Erosivity has a markedly seasonal behavior in accordance with the rainy season from October to March. This season concentrates 86 % of the estimated EI30 values, with monthly maximum values of up to 2,342 MJ mm ha-1 h-1 month-1 between December and January, and minimum of 34 MJ mm ha-1 h-1 month-1 in August. The highest values were found in the Mantiqueira Range region (annual average of up to 12,000 MJ mm ha-1 h-1), a region that should be prioritized in soil and water conservation efforts. From this validation, good precision and accuracy of the model was observed for the long period of the annual average, which is the main factor used in soil loss prediction models.

Soil is one of the most important natural resource and its heterogeneity reflects the variability of its chemical and physical attributes. Soil heterogeneity occurs due to the natural process of formation and use by men and management. The objectives of this study were to evaluate the spatial variability of physical and chemical soil attributes and map the spatial distribution of these in Posses sub-basin, Extrema, representative of the Atlantic Forest biome present in southern Minas Gerais. For this, samples (0-0.20 m depth) were collected at 150 points, and their physical and chemical attributes were determined. Variables: Ca, Mg, K, P, pH, organic matter (MO), geometric mean diameter of aggregates (DMGcp), weighted mean diameter of aggregates (DMPcp) and flocculation index (IF) showed spatial dependence structure, which allowed mapping from geostatistical techniques. P, DMGsp and DMPsp presented structure with nugget effect, possibly due to an insufficient distance to capture spatial dependence in the sample for these attributes, and human interferences. The variation for Ca can be explained due to lime application, which occurred in some small properties located in the sub-basin. The DMGcp, DMPcp, and IF evaluated were adjusted in line with each other, indicating good soil aggregation.

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