LambdaGeo — Research Lab in Computing and Geotechnologies

LambdaGeo — Research Group

lambdageo@ufma.br

UFMA — São Luís, MA, Brazil

LambdaGeo is a research group at the Federal University of Maranhão (UFMA) working at the intersection of Computer Engineering, Geosciences, and Open Science, registered in the CNPq Directory of Research Groups.

We develop reproducible, open-source tools for spatial simulation, semantic data integration, and environmental modeling — and we publish all our teaching materials as free, open books.

How can geospatial models be built so that others can understand, reuse, and trust them?

🔬 Research Areas

🌍 Dynamic Spatial Modelling

Our flagship research area — modern, Python-native tools for discrete spatial simulation (Cellular Automata, System Dynamics, and Land Use & Cover Change).

Main project: DisSModel and DisSLUCC — an independent Python alternative to INPE’s TerraME/LuccME, which remain the reference.

🔗 dissmodel.github.io · GitHub Organization · pip install dissmodel

🗺️ Repository map

DisSModel spans two GitHub organizations: the packages live in DisSModel, and the reference outputs, benchmarks, study cases, workflow and book live here in LambdaGeo. The repository map shows how they all connect, from the TerraME/LuccME reference to the open-data workflow.

Declarative TOML pipelines turn open data into model-ready grids, and the model components are checked against TerraME/LuccME reference outputs. Every experiment records SHA-256 checksums, TOML specs, and Git commits for full reproducibility.

Textbooks (open-access, in Portuguese — see the Geospatial Track):

Introdução ao Geoprocessamento e Sensoriamento Remoto — the entry point: remote sensing with Google Earth Engine and spatial databases with PostGIS and QGIS.
Geospatial Modeling with Python — a didactic textbook covering geospatial Python from scratch; chapters 1–16 are independent of DisSModel.

DisSModel builds on two decades of prior work: TerraTranslator (Lima Júnior, 2002; with Gilberto Câmara) → TerraHS (2005, models as verifiable artifacts) → TerraME / LuccME (2007–10, INPE, spatially explicit dynamic models) → DisSModel (2024–26, Python, FAIR, verified against TerraME/LuccME).

🌱 Other Areas of Interest

Ongoing interests with less active focus today, but part of the group’s intellectual lineage.

🔗 Semantic Web & Geoinformatics

We bridge Linked Open Data (LOD) with Geographic Information Systems (GIS) to enable interoperable, FAIR-compliant spatial research:

Project	Description	Link
rdfmapper	Declarative Object-RDF Mapper for Python	GitHub
QGISSPARQL	Bridge Triple Stores ↔ QGIS for semantic mapping	GitHub
DBCells	Publish spatial modeling data as Linked Data cubes	GitHub

These projects feed into DisSModel’s provenance layer.

Roots trace back to TerraTranslator (Lima Júnior, 2002; with Gilberto Câmara), a tool for converting geographic data formats. Rovedy A. B. Silva’s 2003 master’s dissertation (INPE, advised by Antônio Miguel Monteiro) extended it to export to GeoBR and GML 3.0 — early work on ontologies and interoperable semantics for geographic data in Brazil, predating today’s widespread use of GML.

λ Functional Programming

TerraHS (2005–2009) — an early vision of scientific models as verifiable, executable artifacts in Haskell. Now fully rewritten in pure Haskell, dropping the original FFI dependency on TerraLib: same geometry, spatial predicates, and generalized map algebra, built from scratch with no system dependencies. Used as teaching material for both functional programming and GIS courses.

PlayReg — a regex engine built on Brzozowski derivatives, following the “A Play on Regular Expressions” functional pearl, generalized via a Semiring abstraction to compute acceptance, match counts, or submatch positions.

Textbook: Introdução à Programação Funcional (Haskell/Clojure/Elixir) — part of the Computing Core series in our open-access Computing Track.

👥 People

Prof. Sérgio Souza Costa — Principal Investigator
Associate Professor of Computer Engineering, UFMA · PPGC&TAmb · PROFCOMP
Focus: reproducible geospatial modeling, functional programming, FAIR data infrastructure.

All members and full profiles →

Mentorship Workflow

We use Notion for mentorship, lecture materials, and project tracking:
profsergiocosta.notion.site

Join LambdaGeo

We welcome motivated PIBIC and master’s students interested in:

Python for scientific computing
GIS, remote sensing, and spatial analysis
Reproducibility, FAIR principles, and open science
Software engineering for research software

📧 Contact: lambdageo@ufma.br with a brief note about your background and interests.

🤝 Partners & Affiliations

UFMA — Federal University of Maranhão
INPE — National Institute for Space Research (Brazil)
PPGC&TAmb — Graduate Program in Environmental Science & Technology
PROFCOMP — Professional Master’s in Computing Education (national network coordinated by SBC)

📡 Stay Connected

Research code: github.com/LambdaGeo · github.com/DisSModel
Software: LambdaGeo tools and packages · DisSModel ecosystem
Publications: Selected papers and full list
Teaching materials: Open-access e-books
Registration: CNPq Directory of Research Groups
Email: lambdageo@ufma.br (group) · sergio.costa@ufma.br (Principal Investigator)

“Do dado aberto ao modelo verificado, em código que qualquer um pode rodar.”
(“From open data to a verified model, in code anyone can run.”)
— LambdaGeo

news

No news so far...

latest posts

Jul 12, 2026	Construindo e Testando uma Biblioteca Haskell: JSON, Pretty Printing e QuickCheck
Jul 11, 2026	Elixir e Phoenix LiveView: Construindo uma Aplicação Todo List do Zero
Jul 11, 2026	Clojure e ClojureScript: Construindo uma Aplicação Todo List do Zero

selected publications

GeoNordeste
AVALIAÇÃO DA ACURÁCIA NA CLASSIFICAÇÃO DE USO E COBERTURA DA TERRA: UM ESTUDO DE CASO NA REGIÃO INTERMEDIÁRIA DE SÃO LUÍS COM O MAPBIOMAS

Thomas Victor de Sousa Malheiros Rocha, Sérgio Souza Costa, Luís Fernando Fernando Cirqueira da Silva Correia, and 1 more author

Revista GeoNordeste, Dec 2025

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A classificação de uso e cobertura da terra é essencial para gerenciar recursos naturais. Este estudo analisou a acurácia de classes como Mangue, Apicum, Praia e Duna dentro do agrupamento SA-23-Z, que cobre 72% da região intermediária de São Luís. Os resultados mostraram alta acurácia para Praia e Duna, apesar de limitações em outras classes, indicando que a classificação do MapBiomas apresenta uma ótima acurácia geral para a região.
@article{rocha2025avaliacao, title = {AVALIAÇÃO DA ACURÁCIA NA CLASSIFICAÇÃO DE USO E COBERTURA DA TERRA: UM ESTUDO DE CASO NA REGIÃO INTERMEDIÁRIA DE SÃO LUÍS COM O MAPBIOMAS}, author = {Rocha, Thomas Victor de Sousa Malheiros and Costa, Sérgio Souza and Correia, Luís Fernando Fernando Cirqueira da Silva and Bezerra, Denilson da Silva}, journal = {Revista GeoNordeste}, volume = {36}, number = {2}, year = {2025}, month = dec, publisher = {Universidade Federal de Sergipe}, doi = {10.33360/geonordeste.v36i.21680}, url = {https://periodicos.ufs.br/geonordeste/article/view/21680}, }
RTG
EXPANSÃO DO DESMATAMENTO NO CERRADO MARANHENSE ENTRE OS ANOS DE 2001 – 2023

Luís Fernando Cirqueira da Silva Correia, Thomas Victor de Sousa Malheiros Rocha, Denílson da Silva Bezerra, and 2 more authors

Revista Tocantinense de Geografia, 2026

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Este trabalho examina a evolução temporal do desmatamento no Cerrado maranhense nos últimos 22 anos utilizando dados do PRODES. A análise revela uma tendência de queda até 2013, seguida por um aumento significativo a partir de 2020, com destaque para as microrregiões de Presidente Dutra, Caxias e Chapadinha. O estudo utiliza uma grade regular para evidenciar a ampla expansão do desmatamento por todo o bioma no estado.
@article{correia2026expansao, title = {EXPANSÃO DO DESMATAMENTO NO CERRADO MARANHENSE ENTRE OS ANOS DE 2001 -- 2023}, author = {Correia, Luís Fernando Cirqueira da Silva and Rocha, Thomas Victor de Sousa Malheiros and Bezerra, Denílson da Silva and Silva Junior, Celso Henrique Leite and Costa, Sérgio Souza}, journal = {Revista Tocantinense de Geografia}, volume = {15}, number = {35}, year = {2026}, publisher = {Universidade Federal do Tocantins}, doi = {10.70860/rtg.v15i35.19356}, url = {https://doi.org/10.70860/rtg.v15i35.19356}, }
RBC
DBCells: An Open and Global Multi-Scale Linked Cells

Sergio Souza Costa, Micael Lopes Silva, Thamyla Maria de Souza Lima, and 1 more author

Revista Brasileira de Cartografia, May 2017

Abs DOI Bib HTML Slides

Land change models require large amounts of data and are difficult to reproduce or reuse. Initiatives to open and link data increase the reproducibility of scientific experiments and data reuse. A core pillar of the linked data concept is the use of Uniform Resource Identifiers (URIs). In this paper, we propose DBCells: an architecture for the publication of a global cellular space where each cell has a URI. This approach allows for the comparison, reproduction, and reuse of models and data.
@article{Costa_Silva_Lima_Moreira_2017, title = {DBCells: An Open and Global Multi-Scale Linked Cells}, author = {Costa, Sergio Souza and Silva, Micael Lopes and Lima, Thamyla Maria de Souza and Moreira, Evaldinolia Gilbertoni}, journal = {Revista Brasileira de Cartografia}, volume = {69}, number = {5}, year = {2017}, month = may, doi = {10.14393/rbcv69n5-44003}, url = {https://seer.ufu.br/index.php/revistabrasileiracartografia/article/view/44003}, }
AABC
The Amazon COP and the Need for Integration between the Environmental and Climate Agendas

Denilson da Silva Bezerra, Sérgio Souza Costa, and others

Anais da Academia Brasileira de Ciências, Sep 2025

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This letter discusses the 30th United Nations Climate Change Conference (COP30) in Belém, Brazil. It highlights the unique opportunity to unify environmental and climate agendas, focusing on five central points: protection of ecosystems, nature-based solutions (NbS), climate justice for indigenous populations, the importance of blue carbon, and practical goals for reducing emissions.
@article{bezerra2025amazon, title = {The Amazon COP and the Need for Integration between the Environmental and Climate Agendas}, author = {Bezerra, Denilson da Silva and Costa, Sérgio Souza and others}, journal = {Anais da Academia Brasileira de Ciências}, volume = {97}, number = {4}, year = {2025}, month = sep, doi = {10.1590/0001-3765202520250533}, url = {https://doi.org/10.1590/0001-3765202520250533}, publisher = {Academia Brasileira de Ciências}, }

RSP

Population-based seroprevalence of SARS-CoV-2 and the herd immunity threshold in Maranhão

Antônio Augusto Moura da Silva, Lídio Gonçalves Lima-Neto, Conceição de Maria Pedrozo e Silva de Azevedo, and 18 more authors

Revista de Saúde Pública, Dec 2020

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This population-based household survey estimated the seroprevalence of SARS-CoV-2 in the state of Maranhão, Brazil. The study found a seroprevalence of 40.4%, one of the highest reported at the time, suggesting that the local herd immunity threshold might have been approached during that period. The results also highlighted the effectiveness of non-pharmaceutical interventions such as mask-wearing and social distancing.

@article{Silva_Maranhao_2020,
  title = {Population-based seroprevalence of SARS-CoV-2 and the herd immunity threshold in Maranhão},
  author = {Silva, Antônio Augusto Moura da and Lima-Neto, Lídio Gonçalves and Azevedo, Conceição de Maria Pedrozo e Silva de and Costa, Léa Márcia Melo da and Bragança, Maylla Luanna Barbosa Martins and Barros Filho, Allan Kardec Duailibe and Wittlin, Bernardo Bastos and Souza, Bruno Feres de and Oliveira, Bruno Luciano Carneiro Alves de and Carvalho, Carolina Abreu de and Thomaz, Erika Barbara Abreu Fonseca and Simões-Neto, Eudes Alves and Leite Júnior, Jamesson Ferreira and Cosme, Lécia Maria Sousa Santos and Campos, Marcos Adriano Garcia and Queiroz, Rejane Christine de Sousa and Costa, Sérgio Souza and Carvalho, Vitória Abreu de and Simões, Vanda Maria Ferreira and Alves, Maria Teresa Seabra Soares de Brito e and Santos, Alcione Miranda dos},
  journal = {Revista de Saúde Pública},
  volume = {54},
  pages = {131},
  year = {2020},
  month = dec,
  doi = {10.11606/s1518-8787.2020054003271},
  url = {https://doi.org/10.11606/s1518-8787.2020054003271},
}

Landsc Ecol
Dynamical coupling of multiscale land change models

Evaldinolia Moreira, Sérgio Souza Costa, Ana Paula Aguiar, and 2 more authors

Landscape Ecology, Nov 2009

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This paper proposes a software organization for building computational models that support dynamical linking of multiple scales, coupling different types of models such as cell-space and agent-based models. We demonstrate how results can flow in both bottom-up and top-down directions, allowing feedback from local actors to regional scales in the Brazilian Amazonia.
@article{Moreira2009, title = {Dynamical coupling of multiscale land change models}, author = {Moreira, Evaldinolia and Costa, Sérgio Souza and Aguiar, Ana Paula and Câmara, Gilberto and Carneiro, Tiago}, journal = {Landscape Ecology}, volume = {24}, number = {9}, pages = {1183--1194}, year = {2009}, month = nov, doi = {10.1007/s10980-009-9397-x}, url = {https://doi.org/10.1007/s10980-009-9397-x}, }
Ci.Inf.
DBacademic: Conectando os dados abertos das instituições de ensino do Brasil

Sérgio Souza Costa, Mateus Vitor Duarte, Micael Lopes Silva, and 2 more authors

Ciência da Informação, Sep 2020

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Este trabalho apresenta o projeto DBacademic, que visa conectar dados abertos de instituições brasileiras de ensino superior utilizando tecnologias de Web Semântica e Linked Data. O artigo detalha o processo de extração, transformação e publicação de dados, permitindo consultas integradas sobre a produção acadêmica e estrutura institucional no Brasil.
@article{Costa_Duarte_Silva_Oliveira_Guimaraes_2020, title = {DBacademic: Conectando os dados abertos das instituições de ensino do Brasil}, author = {Costa, Sérgio Souza and Duarte, Mateus Vitor and Silva, Micael Lopes and Oliveira, Eddye Candido and Guimarães, José Victor Meireles}, journal = {Ciência da Informação}, volume = {49}, number = {3}, pages = {142--158}, year = {2020}, month = sep, doi = {10.18225/ci.inf.v49i3.5500}, url = {https://revista.ibict.br/ciinf/article/view/5500}, }

IntechOpen

Spatially Explicit Modeling for Impacts of Sea-Level Rise in the Baixada Maranhense, Brazilian Legal Amazon

Denilson da Silva Bezerra, Sérgio Souza Costa, Flávia Rebelo Mochel, and 4 more authors

In Dynamics of the Oceans - Variability, Hydrological Cycles, and Sea Level Change, 2025

DOI Bib HTML

@incollection{Bezerra25,
  author = {Bezerra, Denilson da Silva and Costa, Sérgio Souza and Mochel, Flávia Rebelo and Santos, Fábio Augusto Siqueira dos and Barros, Klinsmann Augusto Lavra and Sousa, Felipe Martins and Bezerra, Janaina Santos},
  title = {Spatially Explicit Modeling for Impacts of Sea-Level Rise in the Baixada Maranhense, Brazilian Legal Amazon},
  booktitle = {Dynamics of the Oceans - Variability, Hydrological Cycles, and Sea Level Change},
  publisher = {IntechOpen},
  address = {London},
  year = {2025},
  editor = {Zhang, Xiaolin and Attada, Raju},
  chapter = {4},
  doi = {10.5772/intechopen.1012210},
  url = {https://doi.org/10.5772/intechopen.1012210},
}

PhD Thesis

Regional scale agent-based modelling of land change: evolving institutional arrangements in frontier areas

S. S. Costa

National Institute for Space Research (INPE), 2012

Abs PDF Slides

A thesis focusing on spatial dynamic modeling, agent-based models, and simulation of land-use change and deforestation in frontier areas.