Coastal Morphology and Human Intervention in Golfo Nuevo, Patagonia Argentina

Abstract

Bunicontro, M.P.; Marcomini, S.C., and Lopez, R.A., 2020. Coastal morphology and human intervention in Golfo Nuevo, Patagonia Argentina. Journal of Coastal Research, 36(4), 780–794. Coconut Creek (Florida), ISSN 0749-0208.The Patagonian coastal zone is a complex and dynamic macrotidal environment that is sparsely urbanized, except locally where large cities are located. This human occupation has affected the natural beach dynamics and induced drastic coastal changes in the past 40 years that demand a redirection of initiatives to provide a basis for management efforts. This study analyzes the coastal morphology and beach characteristics of Golfo Nuevo (Chubut, Argentina) for modelling coastal behaviour through field measurements along 17 beach profiles. Beaches were classified into four types according to their sediment grain size, morphology, and morphometric parameters (beach width and gradient). Also, the coast was divided into five categories according to the coastline morphologies and environmental quality: (1) littoral pediments, (2) cliff-top dunes and aeolian ramps, (3) active cliffs, (4) beach ridge terraces, and (5) dunes. Additionally, different human interventions were analyzed to determine how they have affected the natural coastal equilibrium. The coast was divided into low, moderate, and high levels of intervention according to the status of the landscape modification. The most shocking activities were identified as mining (gravel and sand extraction), coastal armouring with hard defences, and urban building. Indeed, the most affected and vulnerable coastal areas have been beach ridge terraces and coastal dunes. It was determined that the coastal extension affected by these human activities reaches at least 37% of the study zone, increasing beach and coastal erosion susceptibility. The coastal classification and the evaluation of human intervention were combined and used to perform an accurate zoning map of the coastal environment. This map represents an essential tool for decision makers of Puerto Madryn city, showing clearly the most vulnerable places where coastal planning strategies urgently need to be applied for a sustainable use of resources.