Deforestation Part 2: Top-down Modelling Pedro R. Andrade Münster, 2013
Representing the process How to develop a deforestation model?
Modelling and Public Policy System Ecology Economy Politics Scenarios Decision Maker Desired System State External Influences Policy Options
Top-down Land Change Models Demand submodel Transition potential submodel Change allocation submodel Land use at t Land use at t+1 Time loop How much? Where? Input data
Transition Matrix (Markov chain) Global economic model Trend analysis Building Scenarios Demand
Simple Demand Demand submodel Difference between years
Potential map Driving factors Neural Network Multivariate Statistics Mathematics Potential Transition potential submodel
Potential map Potential – CLUE like Transition potential submodel Protected Areas Ports Roads Deforestation Subtract from Deforestation
Potential map at t Landscape map at t Landscape map at t+1 Demand t+1 Rank-order Stochastic Iterative Allocation submodel Allocation
deforestation.lua Three strategies for computing potential: Neighborhood: Based on the average deforestation of the neighbors Regression: Based on distance to roads, ports, and protected area Mixed: Based on these four attributes Fixed yearly demand
Models need to be Calibrated and “Validated” t p - 20 t p - 10 tptp Calibration Validation t p + 10 Scenario Source: Cláudia Almeida
Goodness-of-fit Source: Costanza, 1989
Goodness-of-fit: Multilevel Source: Costanza, 1989
Fit According to Window Size
Goodness-of-fit of Land Change Models
Normalize the error according to the demand Compute error instead of fit
Exercise Use the PRODES data as yearly demand (from “total-prodes.lua”) Compute the final real deforestation summing up the deforestation data in 2001 with the yearly PRODES until 2011 Use the multi-resolution metric to calibrate the different potential strategies by changing the weights manually (see an example of computing the goodness-of-fit in “check-fit.lua”) Is it possible to be better than the allocation from the potential based only on the neighborhood?
Land Change Models x Cellular Automata Grid of cells Neighbourhood Finite set of discrete states Finite set of transition rules Initial state Discrete time Behavior parallel in space Read from the neighbors and write in the cell Can a land change model be considered a Cellular Automata?