Análise estatística da influência da precipitação e de características do solo na variação do nível d´água em área de recarga do aquífero Guarani / Statistical analysis about the influence of precipitation and soil characteristics on the water level fluctuation on recharge area of the Guarani aquifer system recharge

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The increasing of water use to different consumes have generated the growing of researches related about groundwater resources. The recharges quantification is a indispensible requirement to management of these resources. The main objective of this research is to analyze the influence of precipitation and soil characteristics on the water level fluctuations on the recharge area of the Guarani aquifer system, using the Ribeirão da Onça pilot-basin to study area. The water level fluctuation was monitoring in 12 wells, during the period of September 2004 until August 2008. The climatology station of CRHEA-USP provides the data about dairy precipitation, to the period of October 2004 to September 2008. In order to reach the proposal objectives were used three statistical methods: clustering techniques, time series analysis and correlation analysis. There is a seasonal pattern of the rains in the region, and the water level fluctuations have the same behavior, with except of wells located in areas where eucalypt are cultivated. The clustering techniques surgeries the formation of five wells groups. The correlation between months variations water level of the wells generated high coefficients. This result, analyzed with the clustering, shows that there are an more importance of soil culture on the water level fluctuation, empathizing the necessity of more specific studies about the soil characteristics, once a time that the porosity was also showed like a important characteristic. The coefficients of correlation between water level dairy fluctuation on the aquifer and dairy precipitation were very small (r <0.5), which shows the existence of a lag period between the events. It was verified that this lag varies from 10 to 20 days. The occurrences of shorts periods of elevation of the water level is result of accumulated precipitations currents on the same period.

ASSUNTO(S)

groundwater Águas subterrâneas agrupamentos chuva métodos estatísticos lag defasagem raining clustering statistical methods

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