Resumo

CIFUENTES-OSSA, María Alejandra; ROSERO-HENAO, Leidy Viviana  e  JOSEPHRAJ-SELVARAJ, John. Detection of shoreline changes in the northern District of Buenaventura using remote sensing. Bol. investig. mar. Costeras [online]. 2017, vol.46, n.1, pp.137-152. ISSN 0122-9761.

This study focuses on detecting the magnitude of shoreline changes of the northern District of Buenaventura, in the Colombian Pacific, over a 30-year period, on a coast where the geomorphology includes beaches, cliffs, estuaries, deltas and salt marshes. Satellite imagery (Landsat MSS, ETM + and OLI TIRS) were used to detect historical positions of the shoreline in order to identify the processes of change, in terms of erosion and accretion, from 1986 to 2015. Statistical analysis of changes was carried out to estimate distances and shoreline change rates, using a tool developed by the United States Geological Survey (USGS): Digital Shoreline Analysis System (DSAS). The statistics on Net Shoreline Movement (NSM) and End Point Rate (EPR), provided information about the magnitude and trends of changes in the shoreline. The results indicate that areas with more advanced processes of accretion correspond to sectors in Boca San Juan, Puerto España and near to La Concepción beach in the Department of Valle del Cauca and in the south of Chavica, in the Department of Chocó; all these sectors are located in the northern part of the study area. Also in the same sectors, particularly around Chavica, the most advanced processes of erosion were found, along with El Choncho beach and a small sector in the Malaga bay. Some sectors of the shoreline remained mostly stable, such as Malaga and Buenaventura Bays. Average shoreline change rate of (-) 0.21m per year was found, reflecting its erosive tendency with maximum EPR values 26.92m of accretion and (-) 21.01m for coastal erosion. Natural processes such as the influence of river discharge and El Niño phenomenon, have contributed to these shoreline changes. The identified erosion and accretion processes can be recognized as priority areas of coastal management in the Colombian Pacific.

Palavras-chave : Buenaventura; Colombian Pacific; Shoreline changes; Erosion; Accretion.

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