Fitting the Curve: Flood Frequency Analyses
Free FFA Webinars:
We were privileged to be joined by Haden Smith, lead developer of the RMC-BestFit software package, for a demonstration of new capabilities in the latest version 2.0 beta. The 13 Nov 2024 demonstration was presented live from the ANCOLD conference in Adelaide, South Australia – which is incidentally also the home of the Australian Water School! Following the RMC-BestFit walk-through, we had an interactive expert panel discussion about conducting flood frequency analyses in the face of climate change. View the webinar recording below, and check out presenter background details and the Q&A transcript here.
The panel discussion addressed audience questions, including:
- How are precipitation and flow data treated differently in BestFit?
- How can we incorporate non-stationarity into flood frequency analyses to account for climate change?
- How can extreme events be incorporated into BestFit?
- Which probability distributions are most appropriate for flood modellers?
- How should BestFit parameters be adjusted to match FLIKE?
In future premium webinar sessions, attendees will receive resources to explore expanded probability distributions and sophisticated modelling techniques like mixture models and bivariate copulas. The free webinar leads into practical workshop exercises presented in upcoming sessions, in which attendees use their own data sets to develop flood frequency analyses, filter outliers, and incorporate non-stationarity. Register for our February 2025 sessions below, or subscribe to be notified of upcoming courses and training opportunities.
Before viewing the November 2024 webinar, we invite attendees to watch our previous free webinar from 2022 covering an introduction to stochastic hydrology, BestFit software, Bayesian estimation, and curve fitting. The webinar included a basic demonstration of conducting a FFA from scratch. View the recording of the free webinar here:
Webinar resources, presenter background details, and the Q&A transcript for the 2022 webinar are available here:
About RMC-BestFit
The USACE Risk Management Center (RMC) has developed RMC-BestFit, which features powerful tools for advanced time series analysis and hydrological modelling. BestFit is Bayesian estimation and fitting software that performs distribution fitting from a choice of thirteen probability distributions. The software features a fully integrated modeling platform, with a graphical user interface, data entry capabilities, distribution fitting analysis, Bayesian estimation analysis, and report quality charts. The Github link also includes relevant academic papers about the background theory.
Version 2.0 introduces powerful new features that enhance time series analysis and hydrological modelling. Key enhancements include seamless data import from USGS and GHCN, advanced hypothesis testing, and the integration of measurement error for more accurate analyses.
- Download links, documentation, and training resources for RMC-BestFit, free software for curve fitting and estimation with a range of probability distributions.
- Download links, documentation, and training resources for the Statistical Software Package (HEC-SSP). HEC-SSP combines all of the statistical analyses capabilities of HEC-FFA (Flood Frequency Analysis), STATS (Statistical Analysis of Time Series Data), REGFRQ (Regional Frequency Computation) and MLRP (Multiple Linear Regression Program).
- This link includes download instructions and background for TUFLOW FLIKE, developed by Professor George Kuczera from the University of Newcastle. FLIKE is an extreme value analysis package that calculates the probability of flood events based on historical records. Instructions for using FLIKE are included in Australian Rainfall and Runoff Book 3.
- Download links, documentation, and training resources for Reservoir Frequency Analysis (RMC-RFA).
- Download a pdf of the USGS Guidelines for Determining Flood Flow Frequency: Bulletin 17C
Climate Change Effects on FFA Estimates
Developing peak flow estimates based on flood frequency analyses can be especially challenging in the face of climate change. Following are some previous free Australian Water School webinars related to climate change with relevance to flood frequency analyses:
- Climate Change Updates to Australian Rainfall and Runoff Guidelines: An expert panel discussion addressing uplift factors for precipitation intensities and other elements of the August 2024 ARR updates.
- Climate Change and Extreme Events: An overview of the science underlying global climate change estimates and how extreme events are likely to be affected.
- ARR to the Extreme: Examining the 2022 extreme flooding in Australia, the relationship to climate change, and how IFD and FFA data should be interpreted and adjusted following extreme events.
- Probable Maximum Flood: Covering the principles behind estimations of probable maximum precipitation and probable maximum flood, including paleoflood analyses and guidelines for Australian PMF assessments.
Additional FFA Resources
Mike Bartles, director of the Corps of Engineers’ HEC-SSP team, provides an overview of new capabilities in HEC-SSP
View a 4-part series on Bulletin 17C, including the history of Bulletins 15, 17, 17A, 17B, and 17C, by AWS presenter Beth Faber
- View a list of Professor George Kuczera’s publications here
- Here’s a download link for the coin toss and Plinko spreadsheet tabs that were highlighted in the webinar
- Here’s an online plinko game which provides an interactive visualisation of bell curves, skews, and other statistical terms
- Converting between Average Recurrence Interval and Annual Exceedance Probability by Tony Ladson
- Bayesian MCMC flood frequency analysis with historical information paper by Reis and Stendinger
- YouTube playlist with BestFit and other FFA related training materials:
FFA Training Opportunities
Join us in 2025 for a premium webinar in which attendees will step through flood frequency analyses with BestFit software. Use your own data and our provided data sets to undertake analyses; we’ll also incorporate extreme and non-stationarity to account for climate change.
Subscribe to the Australian Water School to be notified of upcoming training opportunities around flood frequency analyses:
Use coupon code “hydroschool-10” at checkout to receive a 10% discount on all on-demand training courses
The 8-part Australian Rainfall and Runoff training series includes individual courses with relevance to stochastic hydrology. Course #2 covers flood frequency analyses. Courses are available for on-demand registration to start any time and complete at your own pace. Get a free 3-month FLIKE license and step through worked FFA examples: ARR Course #2: Flood Frequency Analysis.
The 8-part Hydrology and Hydraulics Essentials training series, also available for on-demand registration, includes courses on meteorology, gauge data, and other topics relevant to flood frequency analyses. Course #4 addresses stochastic hydrology, including the development of flood frequency analyses from scratch using Excel.
Use coupon code “hydroschool-10” at checkout to receive a 10% discount on all on-demand training courses
Contact us with any queries.