Dinâmica da inundação em fitofisionomias do Pantanal Mato-Grossense

Abstract

In the Mato Grosso Pantanal, the annual variation of water levels, differences in hydrological regime, variations in topography and soil type provide, in addition to a non-flooded areas, permanent, periodically and rarely flooded areas. In this context, studies on the flood level and fluid dynamics, as well as on the factors influencing it, such as precipitation and physical and water-physical characteristics of the soil, can support restoration, conservation and management of flood plains. The objective of this study was to model the fluid dynamics in phytophysiognomies of the Pantanal of Mato Grosso, to correlate the variation of the flood and the water table with the precipitation and the physical and hydrological characteristics of the soil. The research was carried out in an area of the Cordillera and four of Cambarás, all located in the SESC Pantanal RPPN, Barão de Melgaço, MT, Brazil. The water table was monitored during two hydrological years, the flooded area was quantified and a description was made of the relationship between the level and flood area of the studied sites and the water level of the Cuiabá River. In addition, through the analysis of main components and correlation, it was verified the relation of the variation of the level of flood and the water table with the precipitation and physical and physical - water attributes of the soil. Starting from 1,36 m, the level of water of Rio Cuiabá is decisive factor of the intensity and of the duration of the flood. They were obtained models of lineal regression that, for the interval from 1,36 to 4,61 meters of level of water of Rio Cuiabá, they allow to esteem the water table, the flood level and the flooded area. It was verified that the

difference of the flood level variation between the study units is associated with the physical and physical- water attributes up to 80 cm depth of the soil, as well as the difference of the water table variation, but the

latter from 80 cm deep. During the flood period, up to 40 cm depth, precipitation exerted a positive influence on the soil moistening process, being an indication that precipitation is a determining factor for the beginning of the flood pulse of the study units.