Tribal Community Resilience: Community Driven Relocation StoryMap

<p>The Biden-Harris administration announced the launch of a new Voluntary Community-Driven Relocation program, led by the Department of the Interior, to assist Tribal communities severely impacted by environmental threats. Through investments from President Biden’s Bipartisan Infrastructure Law and Inflation Reduction Act, the Department is committing $115 million for 11 severely impacted Tribes to advance relocation efforts and adaptation planning. Additional support for relocation will be provided by the Federal Emergency Management Administration (FEMA) and the Denali Commission. Alaska communities located along coastlines and tidally influenced rivers are vulnerable to coastal erosion. These communities face advanced planning decisions, such as implementing shore protection or moving infrastructure. This work aims to provide quantitative erosion exposure data to Alaskans that can be combined with local knowledge and evidence for developing hazard mitigation plans and strategies to address erosion. DGGS Report of Investigation 2021-3, Erosion exposure assessment of infrastructure in Alaska coastal communities, provides estimated erosion exposure for 48 communities from the Bering to the Beaufort seas. The Division of Geological &amp; Geophysical Surveys conducted a shoreline change assessment to forecast 20-, 40-, and 60-year erosion estimates using the Digital Shoreline Analysis System (DSAS; Himmelstoss and others, 2018), and estimated the replacement cost of infrastructure in the forecast area. The geodatabase includes mean erosion forecasts and maximum uncertainties for 38 communities along with infrastructure locations and classification derived from Alaska Division of Community &amp; Regional Affairs digital mapping products (DCRA, 2021) for 44 communities. All files are available from the DGGS website: https://doi.org/10.14509/30672. The sea level rise (SLR) coastal inundation layers were created using existing federal products: the (1) NOAA Coastal Digital Elevation Models (DEMs) and (2) 2022 Interagency Sea Level Rise Technical Report Data Files. The DEMs for the Continental United States (CONUS) are provided in North American Vertical Datum 1988 (NAVD 88) and were converted to Mean Higher High Water (MHHW) using the NOAA VDatum conversion surfaces; the elevation values are in meters (m). The NOAA Scenarios of Future Mean Sea Level are provided in centimeters (cm). The MHHW DEMs for CONUS were merged and converted to cm and Scenarios of Future Mean Sea Level were subtracted from the merged DEM. Values below 0 represent areas that are below sea level and are “remapped” to 1, all values above 0 are remapped to “No Data”, creating a map that shows only areas impacted by SLR. Areas protected by levees in Louisiana and Texas were then masked or removed from the results. This was done for each of the emissions scenarios (Lower Emissions = 2022 Intermediate SLR Scenario Higher Emissions = 2022 Intermediate High SLR Scenario) at each of the mapped time intervals (Early Century - Year 2030, Middle Century - Year 2050, and Late Century - Year 2090). The resulting maps are displayed in the CMRA Assessment Tool. County, tract, and tribal geographies summaries of percentage SLR inundation were also calculated using Zonal Statistics tools. The Sea Level Rise Scenario year 2020 is considered “baseline” and the impacts are calculated by subtracting the baseline value from each of the near-term, mid-term and long-term timeframes. Thumbnail image and following quote courtesy of The Yurok Tribe, “Klamath River estuary on the Yurok Indian Reservation, anticipated area of greatest direct impact from sea level rise.”</p>

Tags: bogs, tcr
Organization: Department of the Interior