João Paulo Cunha de Menezes

Correlação entre uso da terra e qualidade da água subterrânea

Este trabalho descreve a correlacao entre parâmetros de uso da terra (area agricultada, area edificada, pastagem, solo exposto e vegetacao intermediaria) e de qualidade da agua subterrânea (pH, solidos totais dissolvidos - STD, K+, Na+, Fe+3, Ca+2, Mg+2, NO2-, NO3-, P total e coliformes), no sul do estado do Espirito Santo. A delimitacao da area de influencia de pocos e a identificacao das classes de uso da terra foram feitas utilizando-se Sistema de Informacoes Geograficas. Por meio da analise de correlacao canonica, foi possivel estimar dois indices: indice de uso da terra e indice de qualidade da agua, ambos padronizados. A correlacao canonica foi significativa entre o primeiro par de variaveis canonicas, indicando relacao linear entre os grupos. Desta forma, e possivel afirmar que o uso da terra influenciou a qualidade da agua subterrânea, principalmente pelo incremento da concentracao de alguns elementos quimicos.

SOIL COVER AND CHEMICAL AND PHYSICAL ATTRIBUTES IN OXISOL IN THE ATLANTIC FOREST BIOME

The objective of this study was to evaluate the chemical and physical attributes of different soil cover in a Oxisol with a strong wavy relief in the Atlantic Forest Biome, in which were selected three watersheds, employed with grazing (watershed P), forest (watershed M) and coffee (watershed C). Deformed and not deformed samples were collected in three depths for physical and chemical characterization. The chemical characteristics of soil in different watershed studies presented low levels of fertility. It was observed an elevation of pH in the soil and contents of Ca2+ and Mg2+ in the watersheds P and C in relation to the watershed M. Due to deforestation and the establishment of agriculture and livestock, there was a decrease in the contents of soil organic matter in the watershed P and C, not altering the physical characteristics of the soil in the watershed P. The implementation of coffee plantation is causing a reduction in the soil quality of watershed C in comparison to the watershed P and M, therefore indicating a need to adequate soil management in this area.

Relação entre padrões de uso e ocupação do solo e qualidade da água em uma bacia hidrográfica urbana

Land use significantly alters the physicochemical and biological processes of natural systems. Thus, surface water sources are integrators of phenomena occurring on the catchment area. In this way, the study aimed to explore the spatial and temporal variability of water quality, and to assess the possible relationships between patterns of land use of the Ribeirao Vermelho basin. Water samples were collected in two periods (summer and winter) and in 15 sections along the watercourse. There has been strong temporal and spatial influence on water quality, and winter period showed the highest nutrient concentrations (Cl-, P, NO3 -), electrical conductivity and organic matter. These values influence the values of the Water Quality Index, ranging from 84 to 9 in the summer period and 66 to 6 in the winter. With respect to trophic conditions of water sources, average values of Trophic State Index of 30 were verified during the rainy season and 93 in winter. Regarding land use patterns, strong relationships in water quality in both periods were observed, the main source of contamination are urban areas. Ribeirao Vermelho and its effluent have shown strong influence of the forms of land use and occupation evidenced by the input organic matter and nutrients in water systems through domestic sewage release untreated and by agriculture in the drainage system of the basin.

Incertezas sobre a modelagem matemática de qualidade da água em curso de água urbano

Mathematical models of water quality have been used as a way to assist managers on the control of water pollution. However, the uncertainties of the input parameters affect the model predictions and therefore the decision on the management process. So, it becomes necessary to identify the input variables that directly affect the uncertainty of the output results of the simulation model. To investigate the uncertainties involved in predicting the minimum concentration of dissolved oxygen, a sensitivity analysis was carried through from using a stochastic method on a deterministic simulation model of the watercourse of depuration in an urban watershed. For this, we used the analysis of Monte Carlo method and the results interpreted with respect to meeting the water quality standards regulated by law. We have found that most affected input variables of the model were the concentration of oxygen and re-aeration coefficient. The use of stochastic method for uncertainty analysis was fundamental in check which parameters should be more careful in its determination that the responses of the simulation model do not suffer large variations when compared to monitored data. Keywords: Water quality; Self-purification; Monte Carlo Simulation.

Mobility of heavy metals in soils of arrangement municipal solid waste

The hydrodispersive knowledge of soil in movement of heavy metals is fundamentally important to prevent and remediate environmental damages. Therefore, studies should be developed on interactions that occur in soils and contaminants solutions. Considering such information in literature, the study of this work is the mobility of Cd, Cu, Pb and Zn metals in three areas of municipal solid waste. The concentrations of ions in the effluent were analyzed using the miscible displacement methodology. Among these evaluated soils, PA presented the lowest potential in relation to leaching of trace elements evaluated. L soil has the highest vulnerability in terms of potential for groundwater contaminations, which requires a greater control in disposal of solid waste containing easily solubilized trace elements.