This is a raster with 1-ft cell resolution representing a detrended version of the ArcGIS Terrain dataset, "2022 Trinity River Focal Reach Digital Terrain" (YT TSP 2023). For further details of the source data can be found in: Pryor, C., T. Grey, and B. Hocker. 2023. 2022 Trinity River focal reach digital terrain model survey report. Report for the Trinity River Restoration Program (TRRP). Yurok Tribal Fisheries Program, Arcata, California. Available: https://www.trrp.net/library/document?id=2627.

Detrending used a mass point file derived from wetted cells (water depth > 0) in the 2022 SRH2D modeled flow output for 450cfs, along with the 2022 DTM's "Terrain_Extent" polygon data plus a regional buffer to create a "hydro-planar" Terrain surface that represents the water surface from the source data. The regional buffer was created by buffering the "Terrain_Extent" polygon by 1,000,000 feet. Elevation for the regional buffer was set to a uniform 1596.69 ft* as previously used for the elevation mid-point of the focal reach. Both the original DTM and this hydro-planar surface were converted to 1 ft resolution rasters. The hydro-planer raster was then subtracted from the DTM-derived raster (a DEM) to yield this Detrended Digital Elevation Model (DtDEM)

* = This elevation is the midpoint between the water surface elevation at the lower end of the DTM and the water surface elevation immediately below Lewiston Dam. While this uniform elevation theoretically could make water flow out of the river near the dam (river is higher than the value of 1596.69) and into the river near the North Fork, the slope created by this is minuscule. At the upper and lower ends of the river where this potential slope would be greatest, it could account for only about 0.025 ft elevation per 100 feet lateral to the river.

Citation: Yurok Tribe Fisheries Department Design and Technical Services Program (YT TSP), 2023. Data Package for 2022 Trinity River Focal Reach Digital Terrain.

This is a raster with 1-ft cell resolution representing a detrended version of the ArcGIS Terrain dataset, "2022 Trinity River Focal Reach Digital Terrain" (YT TSP 2023). For further details of the source data can be found in: Pryor, C., T. Grey, and B. Hocker. 2023. 2022 Trinity River focal reach digital terrain model survey report. Report for the Trinity River Restoration Program (TRRP). Yurok Tribal Fisheries Program, Arcata, California. Available: https://www.trrp.net/library/document?id=2627.

Detrending used a mass point file derived from wetted cells (water depth > 0) in the 2022 SRH2D modeled flow output for 450cfs, along with the 2022 DTM's "Terrain_Extent" polygon data plus a regional buffer to create a "hydro-planar" Terrain surface that represents the water surface from the source data. The regional buffer was created by buffering the "Terrain_Extent" polygon by 1,000,000 feet. Elevation for the regional buffer was set to a uniform 1596.69 ft* as previously used for the elevation mid-point of the focal reach. Both the original DTM and this hydro-planar surface were converted to 1 ft resolution rasters. The hydro-planer raster was then subtracted from the DTM-derived raster (a DEM) to yield this Detrended Digital Elevation Model (DtDEM)

* = This elevation is the midpoint between the water surface elevation at the lower end of the DTM and the water surface elevation immediately below Lewiston Dam. While this uniform elevation theoretically could make water flow out of the river near the dam (river is higher than the value of 1596.69) and into the river near the North Fork, the slope created by this is minuscule. At the upper and lower ends of the river where this potential slope would be greatest, it could account for only about 0.025 ft elevation per 100 feet lateral to the river.

Citation: Yurok Tribe Fisheries Department Design and Technical Services Program (YT TSP), 2023. Data Package for 2022 Trinity River Focal Reach Digital Terrain.