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The use of hydrological models is widely used for information purposes of flow regimes in watersheds and to support when failures occur in measurements. This study aimed to calibrate a hydrologic model at Ibicuí da Armada watershed on southwest of Rio Grande do Sul State, in order to simulate their regime of daily flows for a period of 250 days ahead. Were used the WIN_IPH2 software for the simulation, adjusting optimization parameters through automatic calibration tests by objective functions, and subsequently checking it's fit. The daily series were acquired from the database provided by Agência Nacional de Águas (ANA) and the Instituto Nacional de Meteorologia (INMET). The objective function that showed the best fit between the sample series was Mean Absolute Deviation function (MAR), proving to be the best to represent the Q90 and Q95. The employment created by WIN_IPH2 software combined with information constraints of flow regimes were quite useful for use in situations that require knowledge of water availability, thus contributing to the improvement of the management action s of water resources. [ABSTRACT FROM AUTHOR]

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Studies evaluating the natural vulnerability of aquifers have relevant importance for the knowledge of subject environmental contamination areas. The correct application in vulnerability maps needs constant studies, aiming the improvement of the analyzes and the development of representative maps of the studied areas. The objective of this study was to evaluate the performance of different models for the interpolation of environmental indicators of aquifer vulnerability using the kriging technique. The study was carried out in the Santa Maria River Basin by analyzing the hydrogeological aspects of 255 tube wells, located in six municipalities in the southwest of the State of Rio Grande do Sul. The data indicated that the high vulnerability class prevailed in 47,45% of the evaluated wells, followed by the medium vulnerability class corresponding to 23,14%; the low vulnerability represented 14,50%, the extreme vulnerability class corresponded to 7,85% and insignificant indicated 7,05%. The spherical, exponential, gaussian and linear models were used to interpolate the data, to define the best fit from the application of the semivariogram function. The adjustments were evaluated through the least squares method, which evidenced the best approach from the spherical model among the tested models. The spatial distribution of vulnerability demonstrated the predominance of high vulnerability in the southern portion of the municipality of Santana do Livramento, central portion of Rosário do Sul, north and northeast of São Gabriel and center of Lavras do Sul. In some areas of the basin, in municipalities of Santana do Livramento and Lavras do Sul was found the class of extreme vulnerability aquifer. [ABSTRACT FROM AUTHOR]

A study was carried out of the hydrogeochemical processes involving the groundwater of the western portion of the Santa Maria Aquifer System (SMAS) in the central region of Rio Grande do Sul. The objective of this study was to characterize the behavior of a portion of the groundwater between São Pedro do Sul, Santa Maria and Restinga Seca municipalities, based on a model between water/rock interaction. Mineralogical and hydrochemical information were analyzed, aiming to model the hydrogeochemical evolution of the aquifer in these municipalities. For this purpose, a processing of the information in a geochemical modeling code was performed, using as previous reference mineralogical studies. The results pointed out the main geochemical interactions responsible for groundwater chemistry, which is strongly dependent of the chemical composition of the recharge waters and the mineralogical contribution of the sedimentary rocks of this aquifer system. The groundwater saturation states showed subsaturation processes tending to the balance of carbonate minerals, indicating the dissolution of these minerals, mainly calcite, as well as supersaturation of clay-minerals ilite, montmorillonite (smectite) and kaolinite, in both cases tending to the alkalinization of the environment. The characterization of the hydrogeochemical properties of aquifers is important for a correct understanding of the processes that occur in it and dominate the regional hydrogeology [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.)

Currently, the use of groundwater for irrigation purposes has become a constant in many brazilian watershed. However, the use of water with high sodium content can bring a lot of damage to agricultural soils, especially the clay soils and with poor drainage. The research aimed to evaluate the sodification risk of Lajeado Erval Novo watershed with the introduction of groundwater for irrigation activities. Therefore, was applied a quali-quantitative model to crosscheck the salts concentration information of groundwater from 14 wells located in the region with geomorphological characteristics of the basin. To evaluate the sodium content of groundwater was used the Sodium Adsorption Ratio (SAR) index as an indicator of the percentage of sodium content in water which can be adsorbed by soil. These indicators combined with mapping Geographic Information System (GIS) of slope characteristics and soil type provided an assessment of the risk of soil salinization in different parts of the basin. As a result, it was evidenced the high risk sodification in southern portion using water for irrigation classified with high SAR index (>18) and very high (>26). Studies of this nature aim to contribute to collection information of interest to achievement of more sustainable practices in agriculture, aiming the strategic use of water resources in the region, serving as a contribution to public sector policies. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Agricultural Sciences / Revista Brasileira de Ciências Agrárias is the property of Universidade Federal Rural de Pernambuco 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 Arquivos de Neuro-Psiquiatria is the property of Thieme Medical Publishing Inc. 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.)