Environmental risks of coarse sand extraction in the Incomati Basin. Case of the Moamba Section headquarters, Maputo Province between 2011 and 2021

Abstract

This study analyzes the environmental risks arising from the extraction of coarse sand in the Incomáti basin, in the Moamba district, in the Moamba-sede locality. For the analysis, we used methods such as literature review, fieldwork, interviews and Preliminary Hazard Analysis (PHA). The study analyzed the phases of the sand extraction process from the installation of equipment, through the production process until the end of the activity. Based on the PHA, dangers and risks were identified, such as contamination of watercourses, alteration of the natural landscape, changes in soil structure, widening of river banks, destruction of riverside vegetation, excessive deepening of the riverbed and even erosion. The study identifies 20 environmental risks associated with sand extraction in the region. These risks were distributed across the different phases of the exploration process: 4 risks (20%) in the installation phase, 13 (65%) in the operation phase and 3 (15%) in the closure phase of activities. The study concludes that the operation phase is the one that causes the most impacts, given the fragility of the environment where the activity is carried out, with the dredging extraction method being decisive in causing the impacts in the basin.