Morfodinámica Costera: Tendencias en las Últimas Cuatro Décadas (1976-2017)

Abstract

The present work offers an analysis of the Veracruz coastal morphodynamics in the last forty-two years (1976-2017) at a regional level for the entire Veracruz coast, as well as in seven particular sites with the potential to function as enclaves of engineering prototypes for the use of wave energy: Barra de Cazones, Palma Sola, Villa Rica, Punta Roca Partida, Playa Hermosa, Montepío and Balzapote. The morphodynamic evaluation contemplated the interpretation of aero-satellite materials (1973, 1976, 1986, 1995, 2000, 2011, 2017), processed in ArcGis 10.2, the same software where its Net Shoreline Movement (NSM) and the End Point Rate (EPR); in addition to the elaboration and interpretation of beach profiles and the determination of the morphodynamic state. In the regional context, progradation is observed extended in most of the north coast, associated with polygenetic conditions, with isolated sectors of retreat in rocky blocks, both sedimentary of the North Gulf Coastal Plain (Cazones) or volcanic structures of the Trans-Mexican Volcanic Belt (Palma Sola and Villa Rica). On the other hand, on the south coast, the cumulative elements of the South Gulf Coastal Plain are interrupted by volcanic cliffs of the Sierra de los Tuxtlas (where the 4 sites corresponding to this region are located), even so, there is an important component cumulative as interdigitized bays between the abrasive promontories. Regarding the particular sites, Cazones presents a regressive average rate of change of -0.31 m/year, Palma sola and Villa Rica of +0.58 and +0.47 m/year, respectively. Of the four sites located in the Tuxtlas area, the average rates of change in three (Punta Roca Partida, Playa Hermosa and Montepío) are less than ±0.20 m/year, which shows certain stability in the erosive and cumulative processes. while in Balzapote the value of +0.85 m/year stands out, where the placement of coastal protection infrastructure favored the accumulation of sediments and therefore coastal progradation. Among the successes are the automated calculation, the uncertainty from the inputs, the multi-scalar approach and the graphic management that can be given to the data, in addition to providing arguments for planning strategies and integrated management of the coastal territory. Even so, due to the dependence on the quality of the inputs, the distance between transects, variance of the results and cartographic generalization, the evaluation at the regional scale has an indicative and synthetic character, unlike the analytical interpretation of the local scale. Keywords: coastal morphodynamics, progradation and regression, net shoreline movement, end point rate, Veracruz.