Model Builder

Model Builder is a suite of spatial analyst tools inside ESRI's Spatial Analyst Extension to ArcView GIS. It enables users to construct, execute, and share spatial models using process flow diagrams. The power of Model Builder over standard GIS platforms is that it enables users to conduct spatial analysis and modeling through a flow-chart type interface that is automated and self-documenting, thereby keeping track of the steps taken to conduct the analysis. Each node of the flowchart represents components of a spatial process. A common type of spatial model evaluates site suitability. To choose the most suitable land for a park, for example, the user is able to consider multiple factors, (such as soil type, land cost, and proximity to residents); conduct arithmetic calculations on certain layers (adding the critical habitat for different species, for example); and give priority to the most important issues through a weighting process. Creating a model in this format makes it possible to run multiple variations of the model without having to recreate the entire model and each one is saved in a separate directory for later retrieval. The models can then be easily replicated by others or easily adapted to future analysis. The user can apply the same model to different geographic areas, for example, by changing the input data, and modify the model to explore "what if" scenarios and obtain different solutions.