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Carolina Faccin
Carolina Faccin
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Urban Dynamics in Coastal Cities

Climate & Environment Urban Form & Land Use
Table of Contents
How is tourism-driven urbanization reshaping the North Coast of Rio Grande do Sul, and what is it doing to sensitive coastal ecosystems?
Period
2025–2026
Location
Osório, Tramandaí and Imbé, North Coast of Rio Grande do Sul, Brazil
Partners
Co-authors Juliana Lombard de Souza and Guilherme Kruger Dalcin
My role
Lead author: research design, data processing in Python, spatial analysis and maps.
Data
MapBiomas land use and land cover (1985–2023) · IBGE demographic censuses (1991–2022) · Google Open Buildings
Tools & methods
Python (GeoPandas, Matplotlib) · Land-cover change analysis · Reproducible pipeline

The challenge
#

The North Coast is one of the fastest-growing parts of the state. Seasonal tourism, second homes and permanent migration have pushed cities into a near-continuous strip along the shoreline. The question was not just how much the cities grew, but over what: dunes, beach vegetation (restinga) and wetlands that protect the coast and are hard to recover once built over.

Approach
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I processed 39 years of annual land-cover maps for three neighboring municipalities, each with a different role: Osório (regional hub), Tramandaí (main tourist center) and Imbé (seasonal growth). Land-cover change was combined with census population trends.

From satellite time series to planning evidence
  1. Time series

    MapBiomas annual land cover, 1985–2023

  2. Processing

    Python pipeline: reclassify, clip by municipality, compute area per class and year

  3. Change analysis

    1985 vs. 2023 maps, class-by-class trends, population growth (IBGE)

  4. Findings

    Where and how urban growth advanced over sensitive ecosystems

Results
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  • The coastal urban agglomeration’s urbanized area grew by 60%, from 112 km² (1985) to 180 km² (2023).
  • The region’s population grew 25.8% between 2010 and 2022; Imbé’s population multiplied 3.6 times between 1991 and 2022.
  • Three distinct patterns: dispersed, fragmented sprawl in Osório (+79%); continuous growth and densification in Tramandaí (+26%); fast, seasonal growth in Imbé (+17%), encroaching on dunes and coastal vegetation (beach and dune cover fell by 40% in Imbé and 30% in Tramandaí).
  • Overlaying the 2023 urban area on the 1985 land cover shows what it replaced: 51% of the new urban land in AULINOR was beach, dune, restinga or wetland, rising to 85% in Tramandaí and 76% in Imbé.

Why it matters
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The results are a warning for coastal planning: urbanization is advancing over areas of high environmental sensitivity, and conurbation means one municipality’s choices affect its neighbors. The paper argues for integrated territorial and environmental management with regional solutions.

I later rebuilt the calculations as an open, reproducible Python pipeline that checks its results against the numbers published in the paper: code and data on GitHub.

Read the paper (PT): Faccin, Souza & Dalcin (2026), Patterns of urban transformation and land use and land cover on the North Coast: Osório, Tramandaí and Imbé.

Figures
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Produced by the open pipeline above.

Map of Osório, Tramandaí and Imbé: urban area in 1985 in dark rust, concentrated along the shoreline and in Osório's center, and new urban area by 2023 in orange, spreading around Osório and along the coast
Urban area in 1985 and new urban area by 2023.
Line chart of urban area from 1985 to 2023: Tramandaí from 18.0 to 22.7 km² (+26%), Imbé from 15.5 to 18.1 km² (+17%) and Osório from 9.7 to 17.3 km² (+79%)
Urban area, 1985–2023 (km²).
Dumbbell chart of urban area in 1985 and 2023 for the AULINOR municipalities, from Capão da Canoa and Tramandaí at the top to Capivari do Sul at the bottom, with the percentage growth of each
Where the urban area grew across the 20 AULINOR municipalities.
Stacked bars with the 1985 land cover of the new urban area: beach, dune and wetland classes dominate in Imbé (76% sensitive) and Tramandaí (85%), and pasture and crops in AULINOR overall
What the new urban land replaced (1985 land cover).
Three stacked area charts of land cover by group from 1985 to 2023 for Osório, Tramandaí and Imbé, with the urban class growing at the top while beach and dune, restinga and wetland shrink
Land cover by group, 1985–2023.
Land-cover maps of Osório, Tramandaí and Imbé in 1985 and 2023, with urban area in orange along the coast, forestry plantations in dark rust spreading inland and a beach and dune strip in yellow in the south
Land cover in 1985 and 2023.