Morphometric characterization of the Poxim-Açu River sub-basin, Sergipe, Brazil

Abstract

Watershed morphometric characterization is one of the most used procedures in hydrological and environmental analysis, with the purpose of understanding local and regional dynamics to support water resource management. This paper analyzed the morphometric variables of the Poxim-Açu River sub-basin, affluent of the Poxim River, which contributes with approximately 30 % of the water supply of the capital of Sergipe. We used SRTM (Shuttle Radar Topography Mission) data for the Digital Elevation Model (DEM), with the scale of 1:250,000, provided by Embrapa Satellite Monitoring and the IBGE topographic chart SC-24-Z-B. Other data were obtained from the Digital Atlas of Water Resources of Sergipe, which were processed in Geographic Information Systems (GIS), as the QGIS 1.6 and ArcGIS 10.1 with Spatial Analyst and ArcHidro extensions. Results will support environmental studies of this watershed. We found that the sub-basin has an area of 128 km2, sinuosity index of 10%, fluvial hierarchy of the 4th order, and a compactness coefficient of 1.76. It is practically straight with an elongated shape and a low tendency to have peaks of floods.