Jussara Cabral Cruz

VULNERABILITY OF THE SERRA GERAL AQUIFER TO CONTAMINATION IN THE CITY OF ERECHIM

The portion of the Hydrographic Region of Uruguay River situated between the Rio Grande do Sul and Santa Catarina states are being evaluatedxa0as potential of hydric resources for hydroeletric enterprises. The City of Erechim is located between the coordinates 27° 29’ 20” S; 52° 10’ 03”Wxa0and 27° 47’ 15”S; 52° 21’ 52” W, northwest region of the state, is part of the volcanic spills of the Serra Geral Formation, Facies Paranapanemaxa0in the Parana basin. The uses of ground waters in the Hydrografic Region of Uruguay are multiple: human, animal supplying, hydrothermalxa0waters, irrigation, mineral water bottling. However, the risk of contamination of ground waters comes together with its growing demand, factxa0that indicates the necessity of this resource management. This work has as objective to evaluate and to spatialize in cartograms GOD systemxa0for evaluation of aquifer pollution vulnerability of the Serra Geral Aquifer System/SASG, forming one unconfined fissural aquifer at outcropsxa0near surface. Of a total of 99 tubular wells registered in cadastre in the System of Ground Water Information SIAGAS/CPRM, the GODxa0system for evaluation of aquifer pollution vulnerability was applied in 55 wells. The cartograms had been generated in the software 8.0 Surferxa0and ArcGIS 9.3, represented in the Universal System Transversa de Mercator/UTM. The GOD system for evaluation of aquifer pollutionxa0vulnerability showed 47 wells inserted in the class of average vulnerability, representing about 85.5% of the total area evaluated of 430.76 kmxa0². The class low occupied 12.7% of the area and only 1.8% were inserted in the negligible class. The layer of variation of the potenciometricxa0quota was between 416 and 780 meters, being observed the occurrence of high regional potenciometrics and low potenciometrics locals. Thexa0regional direction of underground flow was in the direction southeast - northeast, for the gutter of the Uruguay River. .

PROTOCOL OF FACTORS ASSESSMENT INFLUENTIAL IN SUSCEPTIBILITY TO EROSION OF RIVER SLOPES

Actions to conserve rivers must be preceded by an environmental diagnosis, however, beyond the body of water, the adjacent atmosphere must also be characterized by ability of recognizing the human impacts and differentiate them of the natural variation of these ecosystems. This study aimed to develop a rapid assessment protocol (PAR), composed of seven parameters - vegetation, soil texture, part of the river, slope inclination slope gradient, soil depth in slope, stroke width of water course, use and land cover -, assigning them weights 0-4, in order to assess the influence of their categories in susceptibility to erosion of the river slope. The PAR was applied in 40 sampling unities (UA) in the watershed of Arroio Val de Buia in Silveira Martins, RS. From the final result of the PAR it was created erosion susceptibility classes, stable, susceptible and instable. The t test showed significant differences between the evaluated units and the Hierarchical Cluster Analysis (AHA) distinguished two classes of UA, according to the categories of susceptibility to erosion resulting from PAR. The basic parameters that determined the groupings were: soil, soil depth in slope, vegetation, the stretch of water course and, land use and land cover. We conclude that the PAR is presented as a good rapid assessment tool river, similar to the studied stream, being useful to the environmental planning considering the regional characteristics.

Qualitative characteristics of water resulting from the introduction of Eucalyptus silviculture in Pampa biome, RS

This study aimed to present the effect on surface water quality of the introduction of eucalyptus forestry in areas that were traditionally used for extensive cattle farming in the Pampa biome, by comparing two paired watersheds located in the municipality of Rosario do Sul, one of them used for forestry and the other in an anthropized natural grassland condition in the Pampa biome. For this purpose, every fifteen days the following parameters were collected and analyzed in two watersheds with different land uses (watershed with grassland and extensive livestock farming – GW and watershed with Eucalyptus - EW) between the months of August 2011 and August 2012: pH, EC, temperature, turbidity and concentrations of SO42-, K+, Ca2+, Mg2+, Cl-, BOD5,20, SS, DS, alkalinity, total coliforms and Escherichia coli. Water quality and land use parameters averages were compared using the t-Test to account for the land use and seasonality. It was concluded that the introduction of forestry activity together with the areas of environmental protection required by the Brazilian legislation (Permanent Preservation Areas - PPA plus Legal Reserve - LR), contributed to the increased concentrations of conductivity, dissolved solids, alkalinity and calcium, and the decreased concentrations of total coliforms and Escherichia coli.

INFLUENTIAL FACTORS IN SURFACE WATER QUALITY IN CATCHMENTS WITHIN THE PAMPA BIOME WITH DIFFERENT LAND USE1

O objetivo deste estudo foi identificar, por meio da tecnica estatistica multivariada, os fatores que melhor caracterizam a qualidade das aguas superficiais em duas bacias hidrograficas rurais com diferentes usos do solo (silvicultura do eucalipto (BE) e campo antropizado com pecuaria extensiva (BC)), localizadas no Municipio de Rosario do Sul, RS - Brasil. O monitoramento dos parâmetros de qualidade da agua foi realizado entre os meses de agosto de 2011 e agosto de 2012, com as analises de: Ca2+, Mg2+, K+, SO42-, Cl-, pH, condutividade eletrica, turbidez, alcalinidade, solidos suspensos, dissolvidos e totais, demanda bioquimica de oxigenio, coliformes totais, Escherichia coli, temperatura, vazao e precipitacao pluvial. Por meio da AF/ ACP, identificou-se que o melhor modelo de ajuste para expressar a qualidade das aguas na BC foi aquele composto por cinco fatores, explicando 83,5% da variância total, enquanto que na BE quatro fatores explicaram 85,12% da variância. Na BC, os cinco fatores foram denominados, respectivamente, sais soluveis, poluicao difusa, solidos, antropico e orgânico. Ja na BE os quatro fatores foram denominados como sais soluvel, mineral, nutricional e com poluicao difusa. Os resultados permitiram concluir que a substituicao do uso tradicional do solo com campo e pecuaria extensiva por floresta plantada atenuou a poluicao difusa na area e, de modo geral, nao implicou grandes alteracoes nas caracteristicas fisico-quimicas e biologicas da agua. Outro ponto observado foi que, neste estudo, a analise fatorial nao resultou em grande reducao no numero de variaveis, uma vez que o melhor ajuste do modelo ocorreu com a inclusao de 15 das 18 variaveis analisadas (BC) e de 17 das 18 variaveis analisadas (BE).