Influence of the sand open-pits and flooded rice in the Paraíba do Sul River floodplain water table, Tremembé municipality, São Paulo state

• Grant number: 08/05400-9
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2009
• End date: February 29, 2012
• Field of knowledge: Engineering - Sanitary Engineering - Water Resources
• Principal Investigator: Helio Nobile Diniz
• Grantee: Helio Nobile Diniz
• Host Institution: Pró-Reitoria de Pesquisa e Pós-Graduação. Universidade de Taubaté (UNITAU). Taubaté , SP, Brazil

Abstract

The Paraíba do Sul River's valley, east of the São Paulo state, is constituted by Taubate sedimentary basin of tertiary and quaternary age. During the recent period (Quaternary) the geomorphology of the valley consists of the Paraíba do Sul river's meander abandoned, periodically subject to the sedimentary fill (sand and organic clays), provoked by the seasonal floods. In the Tremembé municipality, the sediments thickness reaches up to 16 meters. Currently, the plains of the Paraíba do Sul River not suffer flooding because the river flow is controlled by several dams located upstream. The artificial floods currently are caused by rice crop in the floodplains. As a consequence, the water level of phreatic aquifer rises on the surface, and the water suffer great evaporation. In addition to this factor, other economic activity influences the phreatic aquifer's level, the sand extraction, which's the abandoned open pit forms artificial lakes with a large area of evaporation. The Tremembé municipality has the largest area of artificial lakes in the Paraiba's Valley, with 29 sand open pits disabled and 16 in activity. This study has the goal to establish hydroclimatological measures in the Tremembé municipality of Paraíba do Sul River's valley area in order to achieve the water balance and compare the water excess with measures of the groundwater's level in order to establish the relationship of these factors in the dynamics of the water table. (AU)