Spatial assessment of sediment production and strategies for reducing erosive processes in a watershed in Northeastern Brazil

Abstract

Due to the importance of studies on environmental impacts and the absence of research on sedimentology in the northeastern Brazil, this research aims to estimate the sediment production in the Goiana River basin (Brazil). The SWAT (Soil and Water Assessment Tool) model, in combination with the corresponding procedure of parameter optimization SWAT CUP (Calibration and Uncertainty Procedures), and the LOADEST model were used to estimate the spatial sediment monthly production and to establish guidelines for the reduction of erosive processes. The information of calibration and validation included the 1999–2011 time span, taking into account climatic, altimetric, and land and soil use datasets. The sediment production in the watershed varied from 0.06 to 8.68 t.ha^-1.year^-1, with the areas having higher values located in the eastern region, near the coast and the basin outflow. In these areas of the basin, the highest average annual precipitation occurs, which indicates precipitation and runoff as the most influential factors in soil erosion and sediment production. The year 2005 showed the highest annual sediment production, totalizing 614,390.30 t for the entire watershed. In the same year, the model produced the highest average monthly flow rates, showing that the flow rate strongly influences the model estimate for the generation of sediment. The estimates pointed out can contribute to improvement in conservation practices in the region and the mitigation of environmental impacts. The preservation of forest areas, environmental awareness, payment for environmental services (PES), and agroforestry systems can be alternatives for the management of natural resources.