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1 st Brazilian Symposium on Global Enviromental Change, Rio de Janeiro, March 2007 Modelling Land Change: The Scientific Challenges Gilberto Câmara Director National Institute for Space Research Brazil Model = a simplified description of a complex entity or process E 0 E 4
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1st Brazilian Symposium on Global Enviromental Change, Rio de Janeiro, March 2007 Modelling Land Change: The Scientific Challenges Gilberto Câmara Director National Institute for Space Research Brazil
Model = a simplified description of a complex entity or process E0 E4 What is a Model? Deforestation deforest Farmer space owns • income • land use • soil type Model = entities+ relations + attributes + rules source: Carneiro (2006)
Application of multidisciplinary knowledge to produce a model. Modelling Complex Problems If (... ? ) then ... Desforestation?
What is Computational Modelling? • Design and implementation of computational enviroments for modelling • Requires a formal and stable description • Implementation allow experimentation • Rôle of computer representation • Bring together expertise in different field • Make the different conceptions explicit • Make sure these conceptions are represented in the information system
Scientific Challenges • “Third culture” • Modelling of physical phenomena • Understanding of human dimensions • How to model human actions? • What makes people do certain things? • Why do people compete or cooperate? • What are the causative factors of human actions?
Limits for Models Uncertainty on basic equations Social and Economic Systems Quantum Gravity Particle Physics Living Systems Global Change Hydrological Models Chemical Reactions Meteorology Solar System Dynamics Complexity of the phenomenon source: John Barrow (after David Ruelle)
Public Policy Issues • What are the acceptable limits to land cover change activities in the tropical regions in the Americas? • What are the future scenarios of land use? • How can food production be made more efficient and productive? • How can our biodiversity be known and the benefits arising from its use be shared fairly? • How can we manage our water resources to sustain our expected growth in urban population?
Modelling Land Change in Amazonia Territory (Geography) Money (Economy) Culture (Antropology) Modelling (GIScience)
Forecast tp + 10 Calibration Calibration Dynamic Spatial Models tp - 20 tp - 10 tp source: Cláudia Almeida
Soybeans Ranchers Small-scale Farming Challenge: How do people use space? Loggers Competition for Space Source: Dan Nepstad (Woods Hole)
Dynamic areas (current and future) Escada et al. (2005) New Frontiers INPE 2003/2004: Intense Pressure Deforestation Forest Future expansion Non-forest Clouds/no data
Altamira (Pará) – MODIS Image – 21 May 2004 Imagem Modis de 2004-05-21, com excesso de nuvens
Altamira (Pará) – MODIS Image – 22 June 2004 6.000 hectares deforested in one month!
Amazonian new frontier hypothesis (Becker) • “The actual frontiers are different from the 60’s and the 70’s • In the past it was induced by Brazilian government to expand regional economy and population, aiming to integrate Amazônia with the whole country. • Today, induced mostly by private economic interests and concentrated on focus areas in different regions.
Modelling Human Actions: Two Approaches • Models based on global factors • Explanation based on causal models • “For everything, there is a cause” • Human_actions = f (factors,....) • Emergent models • Local actions lead to global patterns • Simple interactions between individuals lead to complex behaviour • “More is different” • “The organism is intelligent, its parts are simple-minded”
Emergence: Clocks, Clouds or Ants? • Clocks • Paradigms: Newton’s laws (mechanistic, cause-effect phenomena describe the world) • Clouds • Stochastic models • Theory of chaotic systems • Ants • The colony behaves intelligently • Intelligence is an emergent property
Statistics: Humans as clouds • Establishes statistical relationship with variables that are related to the phenomena under study • Basic hypothesis: stationary processes • Exemples: CLUE Model (University of Wageningen) y=a0 + a1x1 + a2x2 + ... +aixi +E
Statistics: Humans as clouds source: Aguiar (2006) Statistical analysis of deforestation
Área de estudo – ALAP BR 319 e entorno (Aguiar, 2006b) ALAP BR 319 Estradas pavimentadas em 2010 Estradas não pavimentadas Rios principais Portos
BASELINE SCENARIO – Hot spots of change (1997 a 2020) % mudança 1997 a 2020: 0.0 – 0.1 0.1 – 0.2 0.2 – 0.3 0.3 – 0.4 0.4 – 0.5 0.5 – 0.6 0.6 – 0.7 0.7 – 0.8 0.8 – 0.9 0.9 – 1.0 ALAP BR 319 Estradas pavimentadas em 2010 Estradas não pavimentadas source: Aguiar (2006b) Rios principais
GOVERNANCE SCENARIO – Differences from baseline scenario (Aguiar, 2006b) Differences: Protection areas ALAP BR 319 Estradas pavimentadas em 2010 Less: 0.0 -0.50 Sustainable areas Estradas não pavimentadas More: 0.0 0.10 Rios principais
The trouble with statistics • Extrapolation of current measured trends • How do we know if tommorow will be like today? • How do we incorporate feedbacks?
Complex adaptative systems • How come that a city with many inhabitants functions and exhibits patterns of regularity? • How come that an ecosystem with all its diverse species functions and exhibits patterns of regularity? • How can we explain how similar exploration patterns appear on the Amazon rain forest?
Results of human society such as economies Source: John Finnigan (CSIRO)
Farms Settlements 10 to 20 anos Recent Settlements (less than 4 years) Old Settlements (more than 20 years) Escada, 2003 Agents and CA: Humans as ants Identify different actors and try to model their actions
Different agents, different motivations • Intensive agriculture (soybeans) • export-based • responsive to commodity prices, productivity and transportation logistics • Extensive cattle-ranching • local + export • responsive to land prices, sanitary controls and commodity prices
photo source: Edson Sano (EMBRAPA) Large-Scale Agriculture
Different agents, different motivations • Small-scale settlers • Associated to social movements (MST, Church) • Responsive to capital availability, land ownership, and land productivity • Can small-scale economy be sustainable? • Wood loggers • Primarily local market • Responsive to prime wood availability, official permits, transportation logistics • Land speculators • Appropriation of public lands • Responsive to land registry controls, law enforcement
Agent model using Cellular Automata 1985 • Small farms environments: • 500 m resolution • Categorical variable: deforested or forest • One neighborhood relation: • connection through roads • Large farm environments: • 2500 m resolution • Continuous variable: • % deforested • Two alternative neighborhood • relations: • connection through roads • farm limits proximity 1997 1997
The trouble with agents • Many agent models focus on proximate causes • directly linked to land use changes • (in the case of deforestation, soil type, distance to roads, for instance) • What about the underlying driving forces? • Remote in space and time • Operate at higher hierarchical levels • Macro-economic changes and policy changes
Game theory and mobility • Two players get in a strive can choose shoot or not shoot their firearms. • If none of them shoots, nothing happens. • If only one shoots, the other player runs away, and then the winner receives $1. • If both decide to shoot, each group pays $10 due to medical cares.
Game theory and mobility Three strategies A - ((10%;; $200; 0) B - ((50%;; $200; 0) C - ((100%;; $200;; 0))
Game theory and mobility • What happens when players can move? If a player loses too much, he might move to an adjacent cell
Flexible neighbourhoods Consolidated area Emergent area
Scale is a generic concept that includes the spatial, temporal, or analytical dimensions used to measure any phenomenon. Extent refers to the magnitude of measurement. Resolution refers to the granularity used in the measures. Scale (Gibson et al. 2000)
The trouble with current theories of scale • Conservation of “energy”: national demand is allocated at local level • No feedbacks are possible: people are guided from the above
The search for a new theory of scale • Non-conservative: feedbacks are possible • Linking climate change and land change • Future of cities and landscape integrate to the earth system
U U U Nested Cellular Automata Environments can be nested Multiscale modelling Space can be modelled in different resolutions
Cell Spaces • Components • Cell Spaces • Generalizes Proximity Matriz – GPM • Hybrid Automata model • Nested enviroment Computational Modelling with Cell Spaces fonte: Carneiro (2006)
2500 m 2.500 m e 500 m Cellular Data Base Resolution