> For the complete documentation index, see [llms.txt](https://futurewater.gitbook.io/sphy-manual/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://futurewater.gitbook.io/sphy-manual/manual/sphy-manual-3.1/appendix-1-input-and-output.md).

# Appendix 1: Input and Output

**Table 25: Overview of SPHY model parameters. The last column indicates whether the parameter is observable, or can be determined by calibration (free).** 

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