Breakdown and crossover analysis

Quickstart

Load managed aquifer recharge demo - explore the effect of changes in assumptions on the financial value of managed aquifer recharge ('basin' and 'injection' scenarios) compared to storage of water in dams ('base').

Load diet water footprint demo - explore the effect of changes in food group footprints on the total water footprint of recommended ('RD') and meat-reduced ('A0) diets.

Introduction

Some analyses, e.g. cost-benefit analysis, involve comparing the value of two or more alternatives. The results depend on estimates of many variables, which are often uncertain. It can be useful to check how the conclusion might change with different assumptions about the estimates of these variables: is it possible that a 'cross-over point' will occur, such that the alternative that has the greater value will change depending on the assumptions we make?

This tool steps through this analysis, allowing you to change assumptions used along the way.

Initial analysis:

1. Define the equations used to calculate the value of each alternative
2. Define the minimum and maximum values of variables that we want to explore

Breakdown analysis:

3. Break-down the initial result obtained for each alternative, showing where it comes from

Cross-over point analysis:

4. Identify cross-over points where values of single variables are changed
5. Identify cross-over points where values of pairs of variables are changed
6. Identify cross-over points where values of many variables are changed

Initial analysis

Several options are available:

• Load demo Financial comparison of value of storing water in dams ('base' scenario) vs. underground via infiltration basins ('basin' scenario) or via injection in a well ('injection' scenario)
• Load combined CSV If you have a CSV file that contains equations, notes and ranges in the format used by this tool.
• Load equations CSV If you have a CSV file that only contains equations. The CSV file should have the first column as the name of each variable, and in other columns the equation to calculate each variable. The header should provide the name for each alternative scenario.
• Equations spreadsheet Spreadsheet entry of equations if you want to enter them manually. The spreadsheet can also be used to modify an existing analysis.
• Set default ranges If you already have equations defined and would like the tool to set default ranges which you can then modify. Minimum and maximum values for each variable are respectively set to 1% and 1000% of the values given in the equations.
• Ranges spreadsheet Spreadsheet entry of minimum and maximum values, if you want to enter them manually. The spreadsheet can also be used to modify an existing analysis.

The analysis can also be saved and wiped clean:

• Download combined CSV Exports a csv that includes ranges, notes and equations for all variables and can be reloaded later.
• Reset to blank analysis Page is reloaded and all changes are discarded.