TGRASS: A temporal GIS for field based environmental modeling

Time in geographic information systems has been a research theme for more than two decades, resulting in comprehensive theoretical work, many research prototypes and several working solutions. However, none of the available solutions provides the ability to manage, analyze, process and visualize large environmental spatio-temporal datasets and the investigation and assessment of temporal relationships between them. We present in this paper a freely available field based temporal GIS (TGRASS) that fulfills these requirements. Our approach is based on the integration of time in the open source Geographic Resources Analysis Support System (GRASS). We introduce the concept of a space time dataset that is defined as a collection of time stamped raster, voxel or vector data. A dedicated set of spatio-temporal tools was implemented to manage, process and analyze space time datasets and their temporal and spatial relationships. We demonstrate the temporal GIS and environmental modeling capabilities of TGRASS by analyzing a multi-decadal European climate dataset.