Cross-shore topographic survey data for the areas of Dillingham and Chevak Alaska between 2016 and 2025

The Polaris Project (https://arcticpolaris.org/) examines how communities in Arctic Alaska are affected by environmental hazards and changing conditions, including coastal erosion and flooding, declining sea-ice cover, and shifts in the availability and access to wild resources. The project is conducted in partnership with the rural communities of Dillingham in the Bristol Bay region and Chevak in the Yukon–Kuskokwim Delta, and is supported by the National Science Foundation (Award 1927827). A warming Arctic is accelerating coastal hazards, driving substantial ecosystem change and threatening infrastructure and subsistence lifeways. Identifying and mapping recent erosion is essential for planning and mitigation in western Alaska. Field campaigns were conducted to collect high-resolution coastal datasets documenting storm-driven flooding and shoreline change. Cross-shore profiles were surveyed using a Trimble real-time kinematic global navigation satellite system (RTK-GNSS), extending from upland features to the waterline and repeated over time to measure coastal change. Repeat profiles reveal significant erosion in both study areas. In Dillingham, surveys conducted between 2016 and 2025 document more than 100 meters of shoreline retreat at some locations, with rates reaching 3.5 meters per year. In Chevak, erosion between 2022 and 2024 averaged approximately 1 meter per year. These combined datasets show a clear and ongoing trend of coastal retreat that can now inform local planning and decision-making. All project results have been provided to Tribal and City governments to support adaptation and preparedness efforts.