Caracterização físico-hidrica de três bacias experimentais do Estado de Pernambuco para suporte à modelagem hidrológica

Abstract

For any study involving the movement of soil water becomes essential to know the physical and hydraulic properties and their correlations. Both proprieties are of fundamental importance in the storage and transport of water and nutrients, in controlling infiltration and runoff, as well as soil conservation. In this context, this study aimed to do a physical-water characterization of three experimental basins (Jatoba and Mimoso / Pesqueira-PE and Xaréu / Fernando Noronha-PE) in the semiarid, in order to generate information for hydrological modeling and subsidies for soil and water management and conservation. It has been evaluated the physical and hydraulic behavior of soil at different depths and vegetation cover. Physical characterization of soils was carried out by laboratory tests on disturbed and undisturbed samples. The hydraulic characterization was conducted through moisture retention curves and through of hydraulic conductivity (K) tests in the field with the Guelph permeameter. Possession of physical variables and soil organic matter pedotransfer functions (PTF) have been tested to estimate the K0 and moisture in particular tensions in order to compare field and laboratory measurements. Among the attributes analyzed, the organic matter was the one with the highest coefficient of variation in depth in the basins and Mimoso Jatoba. There was also high variability of saturated hydraulic conductivity (K0) in depth, in the three basins. It was concluded that the hydraulic conductivity no significant difference in hydraulic conductivity means has been verified for the different vegetation covers. Among soils, the Vertisol presented the highest capacity to retain water. It is concluded that the proposed PTF showed low prediction of K0. The PTF for estimatingsoil moisture, also showed low prediction for soils at Xaréu Basins. In the Jatoba and Mimoso Basins, the best prediction for soil moisture at field capacity was obtained by the model proposed by Meng et al. (1987) and the humidity at wilting point, the equation based on the mean texture proposed by Oliveira et al. (2002) showed the best performance. For the water available content for the equation based on unique data set proposed by Oliveira et al. (2002), and Massuti (1997) model showed a good prediction.