Understanding flooding processes in Hawaiʻi and Southeast Alaska

Vaguely abstract overhead image of brown turbulent river waters
With precipitation changes triggered by climate change, it is important to understanding flood-generating mechanisms better.

Flooding potentially threatens life, property, cultural resources, and natural ecosystems of cultural significance in both Hawaiʻi and Southeast Alaska. The main mechanisms that generate floods are intense rain from different types of storms in both locations and snow or glacial melting processes in Alaska. These flood‐generating mechanisms may not change uniformly in a future climate, and floods may increase or decrease in magnitude or change in seasonal timing. To understand how climate change may affect flooding in Southeast Alaska and Hawaiʻi, researchers need to understand the distribution and influence of underlying flood-generating mechanisms better.

As a step toward identifying or further refining understanding of the main mechanisms generating annual peak streamflows, the current study will select candidate stream gauges for Hawaiʻi and Southeast Alaska in a collaborative process. Possible site-selection criteria include (1) availability of existing peak-flow data, (2) location in relation to current and potential future climate conditions, and (3) community and ecosystem concerns. Other considerations include which floods, ranging from exceptionally large floods to more frequent small floods, are more likely to produce effects of concern to stakeholders.

A brief exploration of existing data will be used as a scoping exercise to engage interested parties and refine concepts for future investigations. Three virtual meetings with subject-matter experts, resource managers, and key stakeholders from both regions are planned: (1) an initial meeting to introduce objectives, identify potential technical and cultural issues, and develop a refined study approach, if needed; (2) a second meeting to discuss preliminary results; and (3) a third meeting to present final results and identify a path forward, future work, and information needs.





Janet Curran
Hydrologist, Alaska Science Center, USGS


Delwyn Oki
Hydrologist, Pacific Islands Water Science Center, USGS