What is a Transport Pathway?

A transport pathway Physical components or compartments through which contaminant species can move and/or be stored, such as aquifers, lakes, sediments, surface soil and the atmosphere. GoldSim provides four different elements for simulating pathways. can be thought of as a transfer function (i.e., an operator), whose input is a mass transfer rate and whose output is a mass transfer rate:

The transport pathway operates on (i.e., delays, spreads, reduces, magnifies) incoming mass transfer rates in order to produce a time history of outgoing mass transfer rates from the pathway. In the absence of decay, transport pathways conserve the mass of contaminant within a system.

Note: Although it is convenient to think of all pathways as transfer functions, this description is not strictly mathematically accurate for Cell pathways that are part of a larger Cell net A network of interconnected Cell pathways that are directly linked by coupled mass flux links..

Physically, transport pathways represent the components of a system through which mass (e.g., contaminant species The chemical (or non-chemical, such as bacterial or viral) constituents that are stored and transported through an environmental system in a contaminant transport model. In GoldSim, the Species element defines all of the contaminant species being simulated (and their properties).) can move and/or be stored. Typically, a pathway will represent all or part of an environmental component, such as an aquifer, stream, soil compartment, lake, or a portion of the atmosphere. You define the properties of the pathways, such as their geometry and which environmental media Materials (such as water, sand, clay, air) that constitute (are contained within) transport pathways. GoldSim provides two types of elements for defining media: Fluids and Solids. (e.g., water, air, soil) they contain.