Urbanizations pathways and climate impacts in two cities of Argentina: how to address enviromental impacts in city rapidly growing?

Abstract

Urban growth patterns significantly influence a city's environmental impact and its resilience to climate change. This study analyzes the distinct urbanization pathways of two medium-sized cities in Buenos Aires Province, Argentina: Tandil, situated in a hilly region, and Bahía Blanca, located in an estuary. Both cities share a temperate climate but present unique topographical characteristics. The World Urban Database and Access Portal Tools methodology was employed to generate Local Climate Zone (LCZ) maps for 2003, 2013, and 2023 for both cities. These maps, combined with population data, provide insights into urbanization patterns and their socio-economic implications. Statistical analysis of LCZ class transitions quantifies changes in impervious and pervious surfaces, enabling an assessment of ecosystem service loss and its impact on the cities' resilience to extreme events such as heat waves and floods. Finally, the potential of Nature-Based Solutions (NbS) for enhancing urban resilience and informing climate change adaptation plans is explored. Results reveal rapid expansion in both cities, with land consumption outpacing population growth. This indicates a decline in ecosystem services, notably the loss of hill cover in Tandil and the degradation of estuary and riparian areas in Bahía Blanca. The conversion of natural LCZs (e.g., forests, grasslands) to built-up LCZs (e.g., compact and open low-rise) has increased impervious surfaces and reduced pervious surfaces, exacerbating the urban heat island effect and diminishing the cities' natural capacity for rainwater absorption. Consequently, both cities face increased vulnerability to heat waves and flooding, posing risks to the urban population and environment. The study identifies specific NbS interventions tailored to each city's unique context to enhance resilience to future hazards. These interventions are integrated into proposed climate change adaptation plans, offering pathways towards more sustainable urban development.