The primary objective of this project is to develop and implement Next-Generation Intensity-Duration-Frequency (NG-IDF) tools tailored for the Arctic region's infrastructure design practices. These tools will address the shortcomings of current design methods in accounting for snow processes and ecosystem transformations, reducing the risk of under- or over-design in locations with snow and permafrost, particularly for Department of Defense (DoD) Arctic installations. The inadequacies in current infrastructure design practices pose a significant risk to DoD installations in the Arctic region. The DoD's critical infrastructure often has a design life exceeding 30 years, making it essential to account for ecosystem transformation and snow-related factors. Permafrost thaw and altered snowmelt timing and rates can significantly affect the resilience of future DoD installations and operations. Accurate flood prediction tools are vital for mitigating these risks and ensuring operational capabilities.

The technology's innovation lies in the development and testing of the NG-IDF toolbox, which will be rigorously constructed and validated at DoD installations in Alaska using advanced modeling techniques. These NG-IDF curves will be paired with a Digital Elevation Model (DEM)-based routing tool, offering continuous streamflow hydrographs and probabilistic flood estimates. The project utilizes meteorological time series and the validated Distributed Hydrology-Soil-Vegetation Model to estimate the water available for runoff, a combination of rainfall and snowmelt, to enhance flood risk predictions for both historical and future periods. The success of the project will be demonstrated by the accuracy of the developed NG-IDF curves, the validation of the routing tool, and the user-friendly dissemination of current and future NG-IDF curves through a web-based delivery system. Ultimately, this technology intends to improve flood risk management and inform infrastructure design decisions in the Arctic, providing a useful resource for DoD staff and supporting adaptation strategies.

This project directly addresses DoD's need to update hydrologic design in Arctic regions, including impacts to extreme runoff from regions with permafrost. This approach can be used in data-sparse locations and is designed for rapid integration in standard engineering design. It was previously demonstrated that NG-IDF curves can reduce the probability of under-design in peak flood estimates by about 70% in the western United States. It is expected that a well-validated NG-IDF tool can also significantly reduce the infrastructure under-design risk in Arctic DoD sites. The DEM-based routing and interface will extend this capability to consider the full time series of streamflow, including both floods and droughts in an easy-to-use tool. Both methods will allow direct consideration of uncertainty to allow risk-based decision-making. (Anticipated Project Completion - 2026)