> For the complete documentation index, see [llms.txt](https://swatplus.gitbook.io/io-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://swatplus.gitbook.io/io-docs/introduction-1/basin-1/codes.bsn/uhyd.md).

# uhyd

| Code | Option                         |
| ---- | ------------------------------ |
| 0    | Triangular Unit Hydrograph     |
| 1    | Gamma Function Unit Hydrograph |

The Unit Hydrograph method is only relevant when simulating at a sub-daily timestep and [gampt](/io-docs/introduction-1/basin-1/codes.bsn/abstr_init.md) = 0.