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Flood Frequency Analysis Framework

Source: R/ffaframework-package.R
ffaframework-package.Rd

This package provides tools for stationary (S-FFA) and nonstationary (NS-FFA) flood flood frequency analysis of annual maximum series data. High-level wrapper functions with the framework_* prefix orchestrate the EDA and/or FFA modules from Vidrio-Sahagún et al. (2024) and generate reports. Users who wish to develop customized workflows may use methods with the following prefixes:

  1. eda_*: Explore annual maximum series data for evidence of nonstationarity to inform approach selection (S-FFA or NS-FFA):

    • Detect statistically significant change points.

    • Detect statistically significant temporal trends in the mean and variability.

  2. select_*: Select a suitable probability distribution using the L-moments.

  3. fit_*: Fit parameters given a distribution and approach (S-FFA or NS-FFA).

  4. uncertainty_*: Quantify uncertainty by computing confidence intervals.

  5. model_assessment() evaluates model performance for using a variety of metrics.

Additional utility functions for visualization and computation are also available:

  • data_* methods load, transform, and decompose annual maximum series data.

  • plot_* methods produce diagnostic and summary plots.

  • utils_* methods implement distribution-specific computations.

Datasets from five hydrometric stations in Canada are provided as representative use cases (other datasets in /inst/extdata are for testing purposes only):

  • Athabasca River at Athabasca (CAN-07BE001): An unregulated station with no statistical evidence of trends or change points (S-FFA recommended).

  • Kootenai River at Porthill (CAN-08NH21): A regulated station with evidence of an abrupt change in mean in 1972 (piecewise NS-FFA recommended).

  • Bow River at Banff (CAN-05BB001). An unregulated station with statistical evidence of a trend in the mean (NS-FFA recommended).

  • Chilliwack River at Chilliwack Lake (CAN-08MH016): An unregulated station with statistical evidence of a linear trend in variability (NS-FFA recommended).

  • Okanagan River at Penticton (CAN-08NM050): A regulated station with statistical evidence of a linear trend in both the mean and variability (NS-FFA recommended).

This package assumes familiarity with statistical techniques used in FFA, including parameter estimation (e.g., L-moments and maximum likelihood), dataset decomposition, and uncertainty quantification (parametric bootstrap and profile likelihood). For an explanation of these methods, see the FFA Framework wiki. For examples, see the vignettes on exploratory data analysis and flood frequency analysis.

See also

Useful links:

Author

Maintainer: Riley Wheadon rileywheadon@gmail.com

Authors:

Other contributors:

  • Environment and Climate Change Canada (ECCC) [funder]