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This dataset contains a UTM Zone 14 2019 Lower Texas Gulf Coast - Colorado River to Rio Grande (US/Mexico border) - shoreline. The 2019 shoreline position was extracted from lidar data acquired by the Bureau between April 2 and June 2, 2019. Laser-range data were combined with aircraft position and orientation determined from ground- and aircraft-based GPS and an inertial measurement unit to determine land-surface position and height above the GRS80 ellipsoid. The Geiod12B model was applied to convert elevation values from heights above the ellipsoid to elevations with respect to North American Vertical Datum of 1988 (NAVD88). To determine the shoreline proxy elevation that best matches the wet-beach/dry-beach boundary at the time of the survey, we examined (1) the 2019 Bureau lidar data and aerial imagery; (2) Gulf shoreline (Sargent Beach to Aransas Pass) lidar data collected by the Bureau in 2013, 2014, and 2015 (Paine and others, 2016); (3) the 2016 lidar data acquired by the USACE (USACE, 2017); (4) beach profiles collected by Bureau researchers and students participating in the THSCMP; (5) GPS-based shoreline mapping conducted by THSCMP students; and (6) the 2016 and 2018 NAIP aerial imagery. Through analysis of wet-beach/dry-beach boundary elevations reported in Bureau- and THSCMP-collected beach profiles (1997-2019), several elevation contours were examined to determine the elevation that best represents the shoreline position most consistent with historical mapping practices. A final shoreline position was extracted from the lidar-derived DEM at an elevation of 1.15 m (3.8 ft) NAVD88, which is equivalent to 1 m (3.3 ft) msl. |