A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...

STUDY OF WATER TABLE’S TOP VARIATION, UNDER THE INTERIOR OFAMAZONIAN TROPICAL TRANSITIONAL FOREST, SINOP, MT, BRAZIL, -PRELIMINARY RESULTS.Shozo Shiraiwa*, Tania Helena Marcelino, Moacir Lacerda*, Welitom Rodrigues Borges,*Universidade Federal de Mato Grosso – Departamento de FísicaAv. Fernando Correia da Costa, sn,Cuiabá – MT - CEP 78060-900shozo@cpd.ufmt.brRecent studies about the soil moisture in a Amazonian transitional forest, the water content in soilindicated that is invariable until approximated four meters depth, without variations on observedpluviometric level. To intend to verify the hydric balance on that transitional forest, geophysicalmethods were applied to determine the top of water table. These methods were Vertical ElectricSounding – VES – with Schulumberger array and Ground Penetrating Radar – GPR . Threemeasure was made: first on May, second on October/2001 and third on March/2002, 50 m apartfrom LBA - Sinop Tower. With maximum AB/2=240m the electrical resistivity apparent rangefrom 37.7Ohm.m to 7812 Ohm.m and indicated that water table’s top under 12.1 m. The GPRline with 200MHz antennas and 50 m long was conduct on same time and the sections of GPRshow irregulars reflectors associated to lateritic beds at 3.5 m and another reflector at 6.0 m. Afterthis results, a monitoring hole was made with 5.3 m depth. From December to January/2002water table’s top change from 5.14 to 3.18m depth, after intense pluviosity. After this until now,this level variety between 3.1 and 3.6 m until now, April/2002.