Avaliação da segurança no entorno da barragem Flores (Maranhão), com base em fatores hidrológicos e na dinâmica de uso da terra

Abstract

Changes in land cover and user in river basins are often associated with hydrological changes that have a potential impact on water storage systems. Bank erosion and siltation are among the main problems found in dam lakes. In the state of Maranhão, the basin contributing to the Flores dam has been undergoing significant changes in the landscape due to the expansion of the agricultural frontier in the Cerrado. State dam management agencies have shown concern about the environmental impact of conditions around and the safety of the Flores dam, given the recent flooding events. This study aims to evaluate the influence of changes in the landscape and extreme events on the safety of the area around the flores dam, located in the municipality of Joselândia, state of Maranhão. To this end, we sought to: (i) analyze the changes in land cover and use around the dam, based on data from the MapBiomas project; (ii) identify the occurrence of extremely rainy months and their association with the flow of the Flores River and the level of the dam of the same name; (iii) assess the conditions of protection of the banks of the Flores dam based on the estimated forest cover of its APP and surroundings; and (iv) observe the dam wall and its surroundings, using a drone. Initially, the geoenvironmental characterization of the surroundings of the Flores dam was carried out, considering the geological, geomorphological and vegetation aspects, and the main uses of the dam lake by the population, as well as its socioeconomic characteristics. Finally, a drone was used to observe the general conditions of the dam structure.