Translated to English language by Tamyres

On Earth, several social and natural systems interact and co-evolve. The understanding of natural phenomena challenges science since its emergence. Various scientists tried to know and describe, using mathematical formulas, the rules that govern these phenomena behaviors, in other words, they constructed mathematical models of these phenomena. On physics and chemistry areas, various models evolved to represent realistically the observed phenomena. In 1807, Dalton modeled the atom as a spherical and indivisible particle without any electric load. In 1913, Bohr demonstrated that the atom had a positive nucleus surrounded by electrons with negative loads and organized in orbits with different energy levels. In past, the Earth was considered flattened. The mathematical models known by science allow the construction of future predictions about several natural systems. To understand the importance the continuous evolution of these models, consider the utility of climatic models to the agribusiness and to the early warning systems of nature disasters.

Despite efforts of anthropology and sociology, the social systems functioning are still not understood. However, currently the social systems are seen as the main driver of changes acting upon nature systems. On the other hand, the nature systems are the main conditioners of social systems behavior. Thus, the social systems affect and are affected by nature systems. So, computer-mathematical models able to simulate the interactions between social and natural systems constitute essential tools to the stakeholders responsible for the definition of politics that aim to regulate the use of Earth’s resources.

Indeed, any decision of governments or private enterprises can be benefited by computational models able to simulate scenarios that evaluate impacts of different strategies: (1) of resource use – space, time, vegetation, water, etc; or (2) of control and response to risks – epidemics, fires, floods, etc. In Brazil, The National Institute of Spatial Researches (INPE) uses TerraME to answer questions related to Land Use and  Cover Change (LUUC) in Amazon [1][2][3] region, to answer questions related to Monitoring, Risk Analysis and Early Warning, and to answer questions about Emission of Greenhouse Effect Gases [4]. Researches of Osvaldo Cruz Foundation (FIOCRUZ) used TerraME to evaluate questions about Dengue Control [5].

TerraME Overview

The TerraME – Terra Modeling Environment – (www.terrame.org) is a toolkit that supports all the phases of environmental model development, namely, model that reproduce the behavior of social and natural processes, showing their interactions and  different changes they promote on each geographic space location. In TerraME, an environmental model is seen as micro-world, namely, a virtual world whose landscape represents a determined region on the Earth, and whose agents, automata and systems that live on it are able to simulate real actors and process of change. TerraME tools are developed by the TerraLAB – Earth Systems Modeling and Simulation Laboratory of the Computer Science Department (DECOM) of the Federal University of Ouro Preto (UFOP) in partnership with the National Institute of Spatial Research (INPE). They are distributed freely to Linux, Windows, and Mac platforms (32 and 64 bits).

The main differential of TerraME in relation with other environment modeling platforms currently available is on the support services for the development of models that consider multiple spatial-temporal scales and on the support to the simultaneous use to multiple modeling paradigms: Systems General Theory, Agents Theory and Cellular Automata Theory. Thus, the modeler does not feel restricted by the choice of a single modeling paradigm and can realistically represent the different scales in which changes occur and in which act the different driving forces of these changes. For instance, in Amazon, the deforestation process is affected locally by the economic situation of small producers, while that globally is affected by commodities prices as soybeans and cattle.

TerraME Graphical Interface for Modeling and Simulation

To support the conception and design of environmental models, TerraME offers a integrated development environment (IDE) known as TerraME GIMS – Graphical Interface for Modeling and Simulation. It allows modelers visually describe their models using diagrams. These diagrams explicit the entities considered in the model, the way how they are hierarchically organized and how they interact with each other. This way, TerraME GIMS facilitates the verification of assumptions in which the models are based. It communicate these assumptions to the decision makers and to the members of the development team that is, routinely, interdisciplinary. The TerraME GIMS is distributed freely as a plugin to the Eclipse platform (www.eclipse.org).

TerraME Interpreter

To support the development of realistic models, TerraME simulator is integrated with Geographical Information System (SIG) that allows modelers to parameterize models from data stored in geographical databases, i.e., temporal series of satellite images and digital maps describing the studied regions. The simulator TerraME is distributed as an interpreter that receives, as entry, the program that represents the environmental model and, so, executes it producing output data that are automatically stored in geographical databases. To facilitate the management and evolution of environmental models, TerraME models are represented on a high level modeling language named TerraML – TerraME Modeling Language, which extends LUA programming language. It was designed to make the job of describe spatial properties, the actors and the processes that changes them. In this language, a complex model can be easily decomposed on simpler models that represent different scales of a same process.

TerraME – Modeling in Multiple Scales

To support model debugging and the analysis of model outcomes, TerraME has a set of components called TerraME Observers. These components are able to show model outcomes, in real-time, as dynamic graphics and maps, on two or three dimensions.

TerraME Observers 

To support the analysis of model sensibility and the projection of simulated scenarios, TerraME simulation nucleus offers a high performance version called TerraME HPA – High Performance Architecture. This simulator version is able to take advantage from the aggregated processing and storage power of multiprocessor and multicomputer hardware architectures, as well as, from computer networks aggregated power. This way, experiments for model sensibility analysis or for the simulation of different scenarios of change can be executed in parallel and in a reduced time.

To support the calibration of environmental models, TerraME offers a set of methods to measure the adjustment between real and simulated maps, in addition to a set of methods to optimize the model parameters so that they maximize the adjustment between the simulated outcomes and the observed data.