Influência da variabilidade climática sobre a linha de costa, riscos e vulnerabilidades do litoral de Maceió, Alagoas

Abstract

The dissertation refers to the investigation of the influence of climate variability on the coast of Maceió and how they can be associated with the vulnerability of the studied area. Over the years, several of these changes have been monitored, and discovering which variables tend to trigger negative impacts is currently essential. Data from the climatic variables of: Total monthly precipitation, Average monthly compensated temperature, Average wind speed, and Average tidal level were used. The Mann-Kendall test was used to analyze and identify trends, which in turn is indicated by theWorld Meteorological Organization (WMO) for studies that work with trends with time series. The T-Student significance test was applied to indicate whether the trend values obtained by the MannKendall test have statistical significance. The temporal series of the meteorological variables of Maceió were submitted to Wavelet Analysis (WA) with the objective of identifying the temporal scales present in the series and this was lead to the identification of the systems or phenomena that occur or influence the local variables. In this way, it becomes clearer which climatic phenomena act on the variables and thus induces climatic interference on the site. For the determination of the positional dynamics of the coastline of the coast of the city of Maceió, a free open source tool called Coastal Analyst System from Space Imagery Engine - CASSIE was adopted. After this stage, the quantitative data referring to the occurrence of erosion processes were refined for a better organization of the results in tables. The elaboration of the layouts was carried out in the free software Qgis version 3.22 Białowieża to focus on the study area. The results showed erosive processes found on the coast of Maceió, with increased areas, critically eroded, as well as stable. In several sectors of the coast, a visual comparison of satellite images from 2002 and another from 2021 was carried out, and sector 3, the region of Pajuçara beach with the most eroded stretch, was identified, which was identified by the LRR method with - 59.6100 m/year, and the same section showed in the trend graphs that the climate variability on the coast had an influence on local meteorological variables and, consequently, on its beaches. With the use of images from the on-site visit, it was noted that in this sector, the already calculated trends of precipitation of 0.5546 mm, Temperature 0.9891 °C, Wind -0.0123 m/s, and Tide Levels 1, 2677 cm, indicated the potential that these variables exercised to modify the beaches on the coast of Maceió, in some cases they showed a situation of vulnerability and risks associated with the coastal zone. When listing the impacts found through the occupation of the beaches, mitigating measures were suggested in order to mitigate and/or reduce the risks caused by erosion and additions to the beaches. The research aimed to stimulate the socio-environmental importance of coastal zones and their preservation through anthropic use and in the face of climate variability, and/or climate change, and developing scientific support for decision-making by public authorities due to the environmental impacts on the coast of Maceio.