Parametric Modeling Increasing Visualization to Give Support to Decision Making in Urban Policies and Projects

The conceptual and practical approaches related to the urban space arrangements present as main characteristic the need of dealing with complex systems, which are to be recognized as being composed by different variables, constituted of different actors, values and dynamics. Time and space are constantly changing, being able of representation by the respective models frame, which are periodical, spatial, conceptual and methodological outlines. In the proposal of such models is found the main contribution of the urban planner, for acting as the decoder of the values in accordance with the different points of view, presenting portraits of the addressed complexity and, ultimately, plays the role of being the collective will transmitter on policies and projects that will regulate the common asset. Among the mostly used methods to structure the ways of regulating the urban landscape it is found the respective breakdown into main criteria, being followed by the integration of such main components for the composition of syntheses that respond the questions to be dealt with. It is the MCE – Multi Criteria Evaluation. Regarding urban planning there are many demands for there are too many actors and interests and specific points of view involved, many variables and in constant changing, and it is necessary to use clear supported criteria in order to obtain the best clarity for the decision making process. The Multi-criteria Analysis had its first application even before the dissemination of the Geographical Information Systems, being that the author are going to favor the criteria integration approach and then expanded by the systemic approach (McHarg, 1969; Chorley and Haggett, 1967, Berry and Marble, 1968). With the introduction of the computational support the process was significantly broadened and there have been developed studies that explore the methodological possibilities (Eastman et al., 1993; Malczewski, 1996, 1999, 2006, 2015; Tomlinson, 1999; Jankowski and Nyerges, 2001; Goodchild, 2004). Reality is broken into main component variables know as criterion, organized as information plans. In each plan the distribution of the mapped criterion is associated to the level of adequacy for the process assessment, in order to be ranked. In addition to the work on each level or criterion, it is also due to be defined the role of each one in the final synthesis, which is known as weigh. The weigh represents the level of significance of that variable with the purpose of the current investigation. For the final frame, logic is that one of the weighted average of weighs and grades. The definition of weigh is related to the choice of a Policy for the urban planning, once it assigns hierarchy to the criteria to be combined. By increasing the weight of a variable in the combination of a set of variables, it gets more defining regarding the urban transformations. On the other hand, the grades definition means the level of adequacy of each component for investigation purposes so the activity of proposing a Project means substituting the content of existing grades within the spatial units that will take such transformations. At the assigning of weights the processes are split into knowledge driven evaluation or data driven evaluation (Bonham-Carter, 1994; Moura, 2007). The Knowledge Driven Evaluation follows the decision makers´ opinions according to their experts´ perspective or according to the significance level. In the Data Driven Evaluation it is observed how criteria behave in relation to the reality outline, where the expected was accomplished, and weights are applied in function of the observed hierarchy. Among the weights assignment methods, best-known ones are the AHP - Analytic Hierarchy Process, proposed by Saaty (1980) and the Delphi, proposed by the RAND - Research and Development - US army department (Dankey and Helmer, 1963; Linstone and Turoff, 2002). Among the methods on uncertainty related to the weights assignment and application it is highlighted the SASE - Sensitivity Analysis to Suitability Evaluation (Jankowski et al., 1997; Ligmann-Zielinska and Jankowski, 2014; Moura and Jankowski, 2015). Visualization methods can compose the bases for the information understanding (MacEachren, et al, 2004; Andrienko et al, 2011; Masala and Pensa, 2014). We are interested, particularly, on the development and application of the processes that favor the visualization of outcomes from the decisions made on the weights assignment. The visualization power increase in order to favor the weights assignment, which is ultimately the definition of a political project for the decision maker, is based on the studies related to the if/then logics and the heuristic principle and then to learn with the information in order to make a decision. The paper herein plays the role of this simulation in a dynamic and interactive process, to review decisions and perspectives. It is based on the Parametric Modeling, which is the criteria and values choice that, combined in algebraic combination, show an investigated reality (Schumacher, 2009). The technique is based on the dynamic cartography logic, for the changes of the parameters can result in an instantaneous visualization of the changes of the land use. The dynamic representation of each choice result in the possibility of reviewing the decisions and to define the best combination of criteria and values assigned. It is illustrated by a case study is in two scales: Pampulha region and a neighborhood in the region. The goal is the study of the criteria and weights assignment for each component in order to investigate the purpose of appointing potential areas for urban expansion and development. The methodology is based in the use of tree apps and software: The City Engine software, from ESRI, is used for the tridimensional representations and opened to the modeling programming processes, especially the Parametric Modeling; Grasshopper because it’s more flexible to develop the algorithms; and Invito, because it was already tested in robust case studies in Italy. In all the methods, the idea is to use the dynamic representation: changing values and variables, the result changes, and the user can learn with the experience and make better decisions. In the case study, there are intentionally chosen several criteria, represented as thematic maps, and is up to the user to decide on the role and weights of each criterion. By the parametric modeling the user can simulate and obtain the simultaneous visualization of each weights combination, understanding, then, in a didactic manner, the meaning of the adoption of a policy in favor of a thematic approach. It is about the if-then logic applied in its core, playing the role of support for the decision making, but also resulting in the task of facilitating the learning of the choices in the urban planning and management processes.