Estudo da variabilidade da piezometria dos aqüíferos freáticos na bacia do alto Rio Jardim - Distrito Federal

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The objective of the present work is to increase the knowledge about the variability of the water table in porous shallow aquifer systems. The study area was the Rio Jardim watershed, situated in the southeast portion of the Federal District (Brazil) and characterized by intense agriculture use. The development of the research was based on monitoring wells water table measures and pluviometer stations referred to a historical data series. These data had been submitted to descriptive and space statistical analyses, through the time series analysis and space multiple regression. The time series analysis was the chosen method to synthesize the seasonal cycles of the water table and rain through of the standardized time series. The analysis of space multiple regression was the chosen method to verify the contribution of independent variable in the behavior of the dependent variable water table of the porous shallow aquifer systems. Based on the analyses it can conclude: (1) The descriptive analyses shows a bimodal behavior to the water table in the clay latosoil aquifer system; the clay latosoil and neossoil aquifer systems show less evident bimodal character in comparison to the clay latosoil aquifer system; the cambisoil and gleisoil aquifer systems show more variable to the water table behavior; (2) The calculated coefficients of variation present high variability of the rain in the analyzed points; (3) In the clay latosoil and latosoil aquifers systems the water table rises begins two months after the beginning of the rainy season and the decreasing initiates more than one month after the dry period starts; in the cambisoils aquifer system the water table levels rises after one to one and a half month after the first precipitation events and in the decreases of the water table levels begins after one month after the dry season; in the gleisoils aquifer system the water table levels answers one month after the rains initiate; (4) In all the aquifers systems the shallower water table presents a decreasing trend, and the deeper the water table levels presents an increasing pattern in the studied period; (5) The time series analysis for the most part of the area demonstrates high variability of the water table. In the north, central and southeastern portions of the study area the variability of the rain is higher; (6) The space multiple regressions pointed out the soil texture as the most important variable to explain the water table variability in the area, followed, by the declivity, geology, hydrogeology and rain.

ASSUNTO(S)

water table and temporal-space statistical analysis piezometria e análise estatística espaçotemporal porous aquifers systems sistemas aqüíferos intergranulares geologia

ACESSO AO ARTIGO

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