How to handle dependant variables?

[Daniel-Trung-Nguyen]

How to handle parameters that are dependent on each other, such as sand, silt, and clay fractions where the sum must equal 1, and their bounds are [0,1]?

[willu47]

Hi. Thanks for the question.

Most global sensitivity measures require inputs to be independent. If you have three parameters with conditional dependencies, one approach you can take is to restructure the parameters so that you have one or two independent variables instead which define the mix of the three dependent variables.

For example x could define the mix between clay and sand and y the mix between (clay or sand) and mud.