Urbanisation on the coastline of the most populous and developed state of Brazil: the extent of coastal hardening and occupations in low-elevation zones

Autor(es)

Pardal, Andre ; Christofoletti, Ronaldo Adriano ; Martinez, Aline Sbizera

• Tipo de documento: Artigo Científico
• Fonte: ANTHROPOCENE COASTS; v. 7, n. 1, p. 15-pg., 2024-06-26.

Resumo

Worldwide, coastlines have been replaced and altered by hard infrastructures to protect cities and accommodate human activities. In addition, human settlements are common and increasing in lowland areas threatened by coastal risk hazards. These urbanisation processes cause severe socioeconomic and ecological losses which demand policy reforms towards better coastal management and climate resilience. A first step in that direction is to comprehend the status of coastal hardening and occupation of vulnerable areas. Here, we mapped the coastline of the most populous and developed state of Brazil: Sao Paulo (SP). Our goal was to quantify the linear extent of natural habitats, artificial structures (AS), and occupations in low-elevation coastal zones (<= 5 m) within 100 m from marine environments (LECZ(100m)) along the coastline and within estuaries. SP coast has a total extent of 244 km of AS, of which 125 and 119 km correspond to AS running along the coastline (e.g., seawalls, breakwaters) and extending from the shoreline into adjacent waters (e.g., jetties, pontoons, groynes), respectively. 63% of the total extent of AS is located in the most urbanised region. Breakwalls were the most common infrastructure (108 km), followed by jetties and wharves (similar to 40 km each), and aquaculture and fishing apparatus (similar to 24 km). Over 300 km of the SP coastline has inland occupations in LECZ(100m): 235 and 67 km are adjacent to sandy beaches and estuarine/river margins, respectively. Coastal hardening is advanced in the central region of SP resulting from intense port activities and armoured shorelines. In other regions, much of coastal urbanisation seems to be driven by secondary usage of the cities, such as real estate development for beach houses and tourism. Our findings suggest that coastal urbanisation poses a major but often neglected source of environmental impact and risk hazards in SP and Brazil. (AU)

• Processo FAPESP: 19/24416-8 - Caminhos de sustentabilidade do oceano para a transformação de conflitos
• Beneficiário: Ronaldo Adriano Christofoletti
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 16/11947-7 - Endurecimento costeiro: status do conhecimento, impactos e projeções futuras
• Beneficiário: Aline Sbizera Martinez
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado