GIS Based Chemical Fate Modeling: Principles and Applications

Chapter 12

Types of Data Required for Chemical Fate Modeling

Alberto Pistocchi, Pilar Vizcaino and Christof J. Weissteiner

Chemical fate and transport modeling requires a large amount and a broad variety of data, which can be classified into three broad groups:

• Emissions.
• Physicochemical properties of substances.
• Properties of environmental media.

Most important, for the spatial prediction of chemical fate and transport, it is essential to know the spatial distribution and intensity of emissions. The issue of estimating emissions deserves a specific discussion, which is provided in Chapter 13.

Physicochemical properties of substances may be determined in laboratory tests, as they depend on the molecule under consideration. They typically include molecular weight, solubility, vapor pressure, and partition coefficients between octanol and water or other laboratory media. Another type of property that is intrinsic to a substance is the degradation rate in different media (air, water, soil, etc.), at least under standardized conditions.

However, degradation and phase partitioning in the different environmental media and phases are not trivial to predict on the basis of laboratory tests, as they strongly depend on landscape properties (such as soil type, organic matter content, suspended particulate and biota in air and water, etc.) and climate (temperature, precipitation, humidity, wind speed, etc.).

Volume and flow properties of environmental media are the drivers of chemical advection ...