1. Overview of VARS-TOOL

VARS-TOOL is a next-generation, multi-method sensitivity and uncertainty analysis software toolbox, applicable to the full range of computer simulation models, including Dynamical Earth Systems Models (DESMs). Developed primarily around the powerful “Variogram Analysis of Response Surfaces” (VARS) framework, VARS-TOOL provides a comprehensive suite of algorithms and methods for global sensitivity analysis (GSA), including ones based on the derivative-based (such as the method of Morris), distribution-based (particularly the variance-based method of Sobol’), and variogram-based (such as VARS) approaches.

The underlying approach of the VARS-TOOL toolkit is described in detail in the following publications:

  1. A new framework for comprehensive, robust, and efficient global sensitivity analysis: 1. Theory: https://doi.org/10.1002/2015WR017558

  2. A new framework for comprehensive, robust, and efficient global sensitivity analysis: 2. Application: https://doi.org/10.1002/2015WR017559

  3. VARS-TOOL: A toolbox for comprehensive, efficient, and robust sensitivity and uncertainty analysis: https://doi.org/10.1016/j.envsoft.2018.10.005

  4. Correlation Effects? A Major but Often Neglected Component in Sensitivity and Uncertainty Analysis (GVARS): https://agupubs-onlinelibrary-wiley-com.cyber.usask.ca/doi/full/10.1029/2019WR025436

  5. A Fresh Look at Variography: Measuring Dependence and Possible Sensitivities Across Geophysical Systems From Any Given Data (DVARS): https://agupubs-onlinelibrary-wiley-com.cyber.usask.ca/doi/full/10.1029/2020GL089829