A Precipitation-Driven Stochastic Approach for Developing Flow- and Stage-Frequency Curves

Código

I-EBHE0211

Autores

Allen Avance, C. Haden Smith, Andrew Verdin

Tema

WG 1.02: Decomposing Complexity

Resumo

The U.S. Army Corps of Engineers (USACE) Risk Management Center (RMC) is pioneering a collection of tools to support the risk assessment of dams and levees, creating a workflow for hydrologic hazards and risk estimation. A key component of this workflow is the development of inflow frequency estimation, achieved either through statistical analysis of flow records or stochastic precipitation-based simulation. For many sites in the United States, there are limited flow records available for statistical analysis. Moreover, existing stochastic simulation tools typically demand significant human and computational effort. Given the large number of dams and levees in the USACE portfolio, there is a need for a tool that supports rapid analysis of flood loadings for dam and levee safety risk analyses. To address this challenge, the RMC has developed the Rainfall Runoff Frequency Tool (RRFT). This cloud-based system stochastically samples Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS) models using regional precipitation-frequency information. Briefly, samples from a regional precipitation-frequency distribution are used to scale historic storm templates and run them through a calibrated HEC-HMS model tens of thousands of times to produce distributions of inflow volume and water level. The RRFT provides an intuitive step-by-step workflow, which allows engineers who are not necessarily stochastic modeling experts to rapidly develop flood hazard curves for dams and levees. This presentation will introduce the RRFT application, detailing its scalable framework that accommodates various user demands from simple to complex stochastic analyses. The results can be used for developing flow- and stage-frequency curves for ungaged basins and informing inflow-volume distributions at specific annual exceedance probabilities for use in RMC-BestFit. Additionally, the presentation will discuss the process for hazard curve development, input requirements, options, limitations, and how RRFT integrates within the broader suite of RMC risk tools, along with a case study example.