An example of a local attribute is the flowpath length of Groundwater blocks. Even though several Groundwater blocks may share common global attributes such as porosity or bulk density, each Groundwater block will have a unique flowpath length. Local attributes are specified in a block's Attribute window. Polygons and blocks can often have more than one input or output, indicating that they receive or discharge contaminants to or from more than one polygon or block along different pathways. The transfer of contaminants from one polygon or block to another is specified by creating a pathway or link between the two.
Links can represent different processes of contaminant transfer, depending on the context.
Some links can represent more than one process, such as a Soil to Human link which can represent both ingestion and dermal exposure pathways. Accordingly, the output from probabilistic simulations consists of a range of values produced during each iteration. The output is described using several statistical quantities such as mean, maximum, minimum, and percentile. A collection of one or more similar attributes is called a data group. Data groups are used to represent lists of attributes that are somehow related.