Tendências de deslocamento populacional no caso de afundamento do solo em Maceió/AL e seus impactos no abastecimento de água em localidades receptoras de realocação

Abstract

After the identification of cracks in the soil and in properties in neighborhoods of the capital of Alagoas – Maceió – in 2018, geological studies pointed to the constant use of the soil for extraction of rock salt as a cause of soil destabilization, thus placing thousands of people living in the neighborhoods of the Pinheiro, Mutange, Bebedouro, Bom Parto and Farol in a vulnerable situation, with the imminent risk of collapse of buildings in the region. Thus begins a process of relocating residents to safe regions on the recommendation of the civil defense. In this context, this work aims to analyze the impacts generated in the Water Supply System (SAA) caused by the abrupt change in water consumption demand in locations receiving relocation from neighborhoods affected by the geological incident in the municipality of Maceió. For that, the population and the supply system of the region were characterized through data from the Brazilian Institute of Geography and Statistics (IBGE), the National Sanitation Information System (SNIS) and the Alagoas Sanitation Company (CASAL). Through population characterization, an estimation of trends of displacement of the migrant population was carried out, also estimating the volume of water demand that will be inserted by it in the receiving neighborhoods. The registration of trunk line networks of receiving locations was traced with the help of QGIS software and exported to EPANET software, where simulations of old and current scenarios were performed in order to verify the changes caused by the change in demand. The simulation results returned that there was a pressure reduction of 19.6% in the Upper Zone 01; 16.6% in the Aviation System and 9.6% in the Pratagy-R1 System; in addition, increases in pressure drop of 9.6% were observed; 6.8% and 9.2% in the respective systems mentioned. Such results imply in situations of both shortages and real losses due to leakage. The strategies used to reduce impacts were the implementation of reinforcement networks, adherence to system expansion projects and application of Active Leakage Control and Rational Water Use methods.