The Role of GIS in Environmental Modelling
Abstract:The commonly accepted roles for GIS in environmental modelling are as a pre - and post - processor, preparing data files for input to the model, and displaying the model results in map form. It is suggested that it may be possible to develop GIS as a modelling tool in its own right, thus avoiding the problems associated with linking separate modelling software with GIS packages. Research shows that a broader range of modelling than previously considered possible can be carried out inside current general purpose raster GIS, albeit with practical constraints. The advantages of this approach are the power of the GIS language (Map Algebra), which can handle complex operations on raster layers with a simple syntax, and the ease with which the modeller can move between model development and testing. A key weakness of current GIS is their poor facilities for representing dynamic process representations, and to overcome this an extension of Map Algebra is suggested to encompass concepts drawn from the field of Cellular Automata (CA) which also operates on a raster cell space. The suggested syntax would allow the implementation of CA models inside GIS extending the range of models which could be represented. In addition, the proposed language retains the power of Map Algebra to define spatial neighbourhoods far more flexibly than the fixed window used in standard CA, thus extending the functionality of the CA approach. The proposed language may be of equal interest to environmental managers and researchers.
Document Type: Regular Paper
Publication date: November 1, 2000