Simulação de manchas de inundação e avaliação da intrusão salina na Bacia hidrográfica do Infulene, considerando o efeito das mudanças climáticas, por meio da simulação hidráulica

Abstract

The present work consists of the application of the HEC-RAS software, with the help of GIS tool “QGIS”, for producing a representative hydraulic model of the basin Infulene hydrographic system, with a view to identifying and mapping the areas affected by floods, and evaluate the effect of saline intrusion on the river's water quality due to of its use in irrigation. The generated model proves to be representative of the real system surface runoff in the basin and, according to the results obtained in its validation, this presents a performance of 77.65%, according to the NSE indicator, and 95.07%, according to according to the skill indicator, a mean squared error (RMSE) of 7.09%, and achieves provide an agreement between Simulated-Observed pairs at a margin of 84.63%. It is noted that for river discharge flows below 91 m3 /s, less than 3% of basin is flooded, and that the tendency of floods is to concentrate in the floodplains, while around the Infulene River. It is noted that the occurrence of extensive damage, and in some cases indistinct, suffered by the population residing in the basin, is due to their housing in areas susceptible to flooding, that is, areas in which floods run off, and that the most affected neighborhoods are the 25 de Junho neighborhood, Inhagoia, Jardim, Trevo, neighborhood or Vale do Infulene, and Luís Cabral, neighborhoods that are located downstream of the river, where Floods tend to spread over larger areas. It is observed, finally, that the Infulene River has, in regions further upstream, a good capacity for self-purification and that the existing gate on the river, located a few meters before its mouth, plays a significant role in reducing the range of saline intrusion, which causes the availability of good quality water for irrigation in larger areas of the river, with regard to salinity (NOSSA TRADUÇÃO).