Use of geotechnologies for morphometric analysis of experimental basin in the semiarid region to support hydrological simulation

The morphometric characteristics help to regulate the hydrological processes of a basin. The understanding of these characteristics is essential for an adequate planning of water resources. The aim of this study was to analyze the sensitivity of the hydrological simulation to different pixel thresholds for the generation of the drainage network and to perform a detailed morphometric characterization of the sub-basin upstream of a fluviometric section (SBSF) installed in the experimental basin of the Jatobá stream, semiarid region of Pernambuco. The following thresholds were considered: 264, 132, 66, 55 and 44 pixels, corresponding to scenarios 1 to 5, respectively. The morphometric analyses were performed through hydrological modeling and the use of mathematical equations, where 25 morphometric indices were evaluated. The results indicated that scenarios 3, 4 and 5 adequately represented the hydrological processes. The physical parameters indicate that the basin has an elongated shape, with a low tendency for flood peaks under normal conditions of climatic events. Although the SBSF presents a low average slope, it was verified the existence of regions with high slopes, favoring the surface runoff, which requires the adoption of conservationist practices and the maintenance of native vegetation.