Variation of the coastline in a medium period (1972-2020): An analysis in themunicipality of Soure, paraense Amazon

Abstract

Estuarine erosion is a significant environmental issue that affects various coastal regions around the world. The western coast of the Pará River estuary mouth is located in the municipality of Soure, in the state of Pará. To analyze the multitemporal variability of erosive and/or accretion rates of the coastline (CL), remote sensing techniques and the Digital Shoreline
Analysis System (DSAS) were employed. Based on orbital imagery from the Landsat sensors (MSS, TM, OLI) from 1972 to 2020, the CL for each year was detected using the Modified Normalized Difference Water Index (MNDWI). This approach enabled the creation of transects from the onshore baseline and the quantification of NSM, EPR, and LRR rates, processed using DSAS v5. The results indicated that erosion is predominant in 57% of the transects, while accretion was observed in 43%, with an average erosion rate of –2.1 m/year (Sector I–SE) and an average accretion rate of 2.55 m/year (Sector II–NE). The results obtained through remote sensing techniques generated substantial data on the dynamics of the CL, corroborating essential technical procedures for implementing mitigation measures in the region and in other geographical areas.