====== Tutorial 4 - Using index lists (Advanced) ======

===== 1/5 =====

This tutorial is an extension to [[Tutorial 3-Using index lists]] and teaches you how to create custom [[Index list|index lists]] and how to use an [[Index operation]] block to sum multi-dimensional parameters and blocks.

**Overview**

It is common in multi-media modelling, that one calculates the contamination level in flora directly from the concentrations of the contaminant in the soil by using concentration factors. The concentration factors depend on both contaminant and plant type. 

By creating a new index list for a set of plants, we can quickly extend the previous model to include concentrations in plants.


**Mathematical model**

//A<sub>Plant</sub>=CF * ( A<sub>Upper Soil</sub> + A<sub>Lower Soil</sub> * RootFactor )//

where

//A<sub>Upper Soil</sub>// is the concentration in the upper soil layer.
>
//A<sub>Lower Soil</sub>// is the concentration in the lower soil layer.

//CF// is a concentration factor which relates the contamination in plant to the contamination in soil.

//RootFactor// is a plant //type// dependent parameter which corrects for the different root depth of different plants.




**Next**

  * [[Tutorial 4-Creating a custom index list|Creating a custom index list (2/5)]]

**References**

  * [[Tutorials|Back to Tutorials]]
  * [[start|Home]]