Frequency & data

Index Flood Method — regional frequency for ungauged sites

Regional frequency analysis using the index-flood approach — combine site and regional information for robust estimates where data is sparse.

What is Index Flood Method?

Regional frequency analysis using the index-flood approach — combine site and regional information for robust estimates where data is sparse.

When would you use this?

  • Ungauged catchments where at-site data is insufficient on its own.
  • Regional studies that need consistent dimensionless growth curves.

How Delta Hydro Studio handles it

  • Transparent handling of regional and at-site information.
  • Pairs with gauge discovery and flood frequency outputs.

How to use it

  1. 1

    Prepare your site statistics and regional pool inputs.

  2. 2

    Configure the index flood model parameters.

  3. 3

    Run the analysis and review growth factors.

  4. 4

    Export results alongside your catchment description.

Methodology & references

Full equations, assumptions, and literature references appear inside the in-app methodology panels for this tool, aligned with South African guidance (SANRAL TRH, SANCOLD, DWS technical manuals) and international references (USDA NRCS, FHWA HDS) where applicable.

Outputs & exports

Export professional Word and Excel report packs, tabulated results, and GIS-friendly layers depending on the tool. Screenshots in marketing materials are refreshed as the UI evolves — the studio always reflects the latest layout.

Ready to run Index Flood Method?

Free tier available — no credit card required to explore.

FAQ

Do I need a desktop GIS install to use Index Flood Method? +
No. Delta Hydro Studio runs in the browser — upload inputs, run calculations, and export professional outputs without local GIS installs for most workflows.
Is there a free tier? +
You can start free on the Stream plan with credits to explore tools. Several hydraulic and delineation tools remain accessible without a paid subscription.
Where are my data and calculations stored? +
Projects live in your Delta Hydro Studio workspace. Export Word, Excel, and GIS formats when you need offline archives or submittals.

Related tools

Ship compliant studies faster

Create your workspace on the Stream plan, then open Index Flood Method when you are ready to run production calculations.