Frequency & data

Flood Frequency Analysis — LP3, GEV, Gumbel & more

Fit and compare frequency distributions (LP3, GEV, Gumbel, Normal, and more) using method of moments, L-moments, and MLE with best-fit ranking.

What is Flood Frequency Analysis?

Fit and compare frequency distributions (LP3, GEV, Gumbel, Normal, and more) using method of moments, L-moments, and MLE with best-fit ranking.

When would you use this?

  • Gauge-based flood frequency for design events or calibration of regional models.
  • Comparing multiple distributions for sensitivity and regulatory defensibility.

How Delta Hydro Studio handles it

  • Several fitting methods and distributions in one comparison view.
  • Designed for professional QA — not a toy spreadsheet macro.

How to use it

  1. 1

    Import or select your annual maximum series.

  2. 2

    Choose candidate distributions and fitting methods.

  3. 3

    Compare goodness-of-fit and pick a defensible model.

  4. 4

    Export quantiles and plots for appendices and peer review.

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 Flood Frequency Analysis?

Free tier available — no credit card required to explore.

FAQ

Do I need a desktop GIS install to use Flood Frequency Analysis? +
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 Flood Frequency Analysis when you are ready to run production calculations.