Malva Andrea Mancuso

Estimativa de Recarga de Aquífero e Enquadramento dos Corpos de Água em Sub-Bacias Parcialmente Florestadas no Noroeste do Rio Grande do Sul

Groundwater has become an important source for water supply, due the increase of restriction for surface water supply, today with scarcity and poor quality conditions. This study aims to estimate the groundwater recharge of SASG and the surface water quality from two small watershed. The watersheds, with different land use, are located at northwest of Rio Grande do Sul State. The groundwater recharge was calculated base on the drain flow rate data, collected in dry conditions. To estimate the runoff time in each watershed it was calculated the concentration time. The flow rate on a dry period was considered as water withdraw from the aquifer. The monitoring program included physical and chemical data from surface water measured during a hydrological year. The land use was mapped base on Google Earth images. The recharge was estimated in 0,58252 m 3 /year/m 2 in the watershed 1 and 0,95476 m 3 /year/m 2 in the watershed 2. The watershed 2 has higher forest land use. According to the water use classification, indicated in the legislation, the surface water is classified as from Class 1.

CARACTERÍSTICAS DA TAXA DE INFILTRAÇÃO E DENSIDADE DO SOLO EM DISTINTOS TIPOS DE COBERTURA DE SOLO EM ZONA URBANA

The aim of this study was to indicate the land use types in Frederico Westphalen (RS) that are more favorable to storm water infiltration, looking forward reducing runoff in the city. To achieve the objective it was perform 45 infiltration tests and soil density in different soil covers. The city was divided in lots, and those were classified according to the following land uses: Mixed Trees (FT), Citrus (C), Grass (G), Crop Rotation (CR) and Bare Soil (SE). The infiltration tests were carried out with the infiltrometer ring method and also there were conducted 45 density tests in a lab. Bare Soils showed the lowest infiltration rate (8.05 mm/h) and the higher soil density (1.58 g/cm3). Soils without green management (SE) do not contribute significantly to rainwater infiltration. FT soils, with less human intervention, showed higher average rates of infiltration (370.3 mm/h) and less than 1.2 g/cm3 of density. Among the remaining land use, airy soils (RC and C) showed better response to infiltration (between 228.5 and 274.0 mm/h). Although the grass is considered a green area, the results indicated that the existence of these areas, by itself, it’s not the better strategy for water infiltration in urban areas.

ANÁLISE E CARACTERIZAÇÃO DA BACIA HIDROGRÁFICA DO CÓRREGO FÁTIMA LOCALIZADO NO MUNICÍPIO DE FREDERICO WESTPHALEN-RS

The question discussed in this paper is recovering Areas of Permanent Preservation (APP) stream Fatima degraded by human action, which is necessary for the recovery of biodiversity and by virtue of the Law. The study area is located in Fatima District, in the city of Frederico Westphalen, RS. Through visits to the local there was a series of impacts. Given this concern about the degraded areas, the present study aims to implement reforestation techniques for the place restoration and de population awareness to prevent future pollution.

DELIMITAÇÃO E MONITORAMENTO VEGETATIVO DA BACIA HIDROGRÁFICA DO LAJEADO CHIQUINHA

The agriculture, livestock and industry are economic activities that require large areas where deforestation is the first negative consequence for the environment where the study and the integrated management of river basins are the only ways to be followed for the diagnosis and as the environmental recovery of these units, leading to balanced ecosystems therein. Thus, the aim of this work is the delineation of the Basin Paved Chiquinha through software Quantum GIS (QGIS), combined the use of Google Earth software images for vegetation monitoring through temporal analysis. We used a tool called historical images from Google Earth to the temporal analysis of the presence of vegetation surrounding the paved, thus following the changes during specific periods of time. The lack of vegetation along the entire length of the paved, besides being in violation of the requirements set forth in law, decreases site preservation and maintenance of biodiversity, also affecting the rates of soil infiltration and runoff.

ANOMALOUS CONCENTRATIONS OF FLUORINE IN GROUNDWATERS

It is believed that concentrations up to 1.5 mg/L of fluorine in the waters are beneficial to human health in the prevention of dental caries in children. But higher values would be harmful and cause stains on teeth, dental fluorosis, and deformed bones. Through the literature review, it was noted that anomalous values of this element occur in crystalline, porous and karstic aquifers. The aim of this paper was to present an evolution of knowledge regarding fluoride anomalous concentrations, performing a case study on the Guarani Aquifer System/GAS. Locally the groundwater has high fluoride concentration in many Brazilian states above standards for human consumption. Many hypotheses were seeking to clarify the origin of these concentrations. However, there is still no consensus among researchers. There is a good relationship with sodic waters character, sulfated and/or chlorinated. Recent studies suggest an association with more saline, thermal waters in confined areas, associating the origin of fluoride to pre–SGA formations, carriers of salts and sulfated minerals. The most consensual hypothesis suggests the existence of mixtures with saline deep waters, indicating that there are areas where vertical flows predominate in relation to the horizontal at the GAS associated this natural process with the ion exchange capacity of the clay minerals.