Coastal morphology and human intervention in Golfo Nuevo, Patagonia Argentina

BUNICONTRO MARÍA PAULA; MARCOMINI, SILVIA; LÓPEZ, RUBEN

JOURNAL OF COASTAL RESEARCH

COASTAL EDUCATION & RESEARCH FOUNDATION

Lugar: Florida; Año: 2020 vol. 36 p. 780 - 794

0749-0208

The Patagonian coastal zone is a complex and dynamic macrotidal environment that is sparsely urbanized, except locallywhere large cities are located. This human occupation has affected the natural beach dynamics and induced drasticcoastal 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 modellingcoastal behaviour through field measurements along 17 beach profiles. Beaches were classified into four types accordingto their sediment grain size, morphology, and morphometric parameters (beach width and gradient). Also, the coast wasdivided 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 humaninterventions were analyzed to determine how they have affected the natural coastal equilibrium. The coast was dividedinto low, moderate, and high levels of intervention according to the status of the landscape modification. The mostshocking activities were identified as mining (gravel and sand extraction), coastal armouring with hard defences, andurban 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 interventionwere combined and used to perform an accurate zoning map of the coastal environment. This map represents anessential tool for decision makers of Puerto Madryn city, showing clearly the most vulnerable places where coastalplanning strategies urgently need to be applied for a sustainable use of resources.